Biomedical subjects

F W Bazer

Publications and source records attributed to F W Bazer.

At least 163 records · Page 9Linked to original sources

PubMed1990

Biological activities of glycosylated and nonglycosylated porcine prolactin.

Nonglycosylated and glycosylated porcine prolactin (PRL) were separated using concanavalin A-Sepharose CL-6B column chromatography and tested for mitogenic and lactogenic activities, as well as immunoaffinity and receptor binding characteristics compared to total (nonseparated) porcine PRL. Mitogenic activity, using Nb2 lymphoma cells, was 4- and 50-fold greater (P less than 0.01) for total PRL than nonglycosylated and glycosylated PRL, respectively. Glycosylated PRL had 64% higher (P less than 0.05) lactogenic activity than nonglycosylated or total PRL. In a homologous radioimmunoassay (RIA), displacement was greatest for total, followed by the nonglycosylated and glycosylated forms of PRL. Competitive inhibition of porcine [125I]-(total) PRL by radioinert total, nonglycosylated and glycosylated PRL in a homologous radioreceptor assay (RRA) indicated similar Ka values for total and nonglycosylated PRL, but different receptor numbers, while radioinert glycosylated PRL had a higher Ka, but bound fewer receptors. Therefore, glycosylated porcine PRL has greater lactogenic activity and higher binding affinity despite decreased mitogenicity, while nonglycosylated PRL had characteristics similar to total PRL. Results from the homologous RRA and the Nb2 assay suggest that both forms of PRL are necessary to achieve biological effects similar to those for total PRL. The two forms of PRL may have individual and collective effects, while changes in the ratio between these forms may influence physiologically diverse effects of PRL on target tissues.

Animals↗

PubMed1990

Development of antibodies for studying conceptus interferons in the cow.

Three synthetic peptides comprising amino acids 100-113, 131-140 and 152-172 of bovine trophoblast protein-1 (bTP-1) were synthesized, coupled to keyhole limpet hemocyanin and used for antibody production in rabbits. Of the resultant anti-peptide antibodies, the antibody directed towards the C-terminal of bTP-1 (152-172) was found effective for recognizing native bTP-1 in enzyme-linked immunoabsorbent assay (ELISA), Western blotting and immunocytochemistry systems. By immunocytochemistry, anti-bTP-1(152-172) reacted with kidney and lung tissue, suggesting that the presence of other interferons in extra-embryonic tissues limits the specificity of the antibody. The other two anti-peptide antibodies showed low cross-reactivity to native bTP-1. None of the three peptides displayed antiviral activity or inhibited antiviral activity of bovine conceptus-conditioned culture medium. Of other anti-interferon antibodies tested, antiserum to human interferon-alpha and bovine interferon-alpha I 1 showed only slight cross-reactivity with bTP-1 and trophoblast protein-1 (oTP-1). A monoclonal antibody raised against oTP-1 also recognized bTP-1 and bTP-1(152-172), suggesting that it recognizes an epitope on the C-terminal region of oTP-1 and bTP-1. In summary, the C-terminal region of bTP-1 is antigenic and accessible to antibodies. Thus, antibodies directed against this region should prove useful for immunochemical studies of bTP-1.

Animals↗

PubMed1990

Purification of bovine trophoblast protein-1 complex and quantification of its microheterogeneous variants as affected by culture conditions.

The bovine trophoblast protein-1 complex (bTP-1) is a group of glycosylated interferon-alpha 11, molecules secreted by the bovine conceptus that plays a critical role in preventing luteolysis during early pregnancy. In the current studies, secretion of individual variant forms of bTP-1 was quantified under a variety of culture conditions that could affect yields of bTP-1 for preparative-scale production of bTP-1. Additionally, a purification scheme for bTP-1 was developed. Conceptuses from Day 17 produced 13 proteins in the molecular weight and pI range characteristic of bTP-1, with 4-5 isoforms (pI = 5.6-6.6) at each of three molecular weight classes (21, 23.2 and 25.8 kDa). The major forms of bTP-1 were two variants of 23.2 kDa having pIs of 6.2 and 6.6. The relative proportion of bTP-1 variants was generally unaffected by culture conditions. Cultured conceptuses secreted bTP-1 at a sustained rate for 3 days and gaseous environment was without major effect on bTP-1 secretion. Conceptuses from superovulated cows also produced bTP-1 at Day 17 of pregnancy, suggesting that superovulation might be a useful method for increasing total bTP-1 yield per cow. The purification scheme that was developed utilized ultrafiltration with Centricon devices to achieve rapid molecular weight fractionation, desalting and concentration of conceptus secretory proteins prior to purification of bTP-1 using anion-exchange and gel filtration HPLC. The resultant preparation of bTP-1 included 9 variant forms of bTP-1 as well as a slight amount of a 45-kDa contaminant. Purified bTP-1 possessed antiviral activity but the specific activity was apparently reduced when conceptus-conditioned medium used for purification was stored for prolonged periods.

Animals↗

PubMed1990

Effects of conceptus and conceptus secretory products on uterine development in the pig.

Pregnant gilts (n = 6) were subjected to surgery on Day 3 of pregnancy and uterine horns, within gilts, were assigned to either (1) ligation 15 cm below the uterotubal junction (REST) or (2) ligation proximal to the uterine body (NONREST). On Day 15 of pregnancy gilts were hysterectomized and length and weight of both uterine horns were recorded. NONREST uterine horns were longer (P less than .05) than those of REST, but weights were similar. Conceptuses from the REST uterine horns were retarded in development. Morphometric analysis of surface (SE) and glandular (GE) epithelial cells detected no effect of treatment on height, width, area, nuclear area or percentage of nucleus. Porcine conceptus secretory proteins (pCSP) were obtained from medium in which pig conceptuses, collected on Day 15 of pregnancy, were cultured for 30 h. Culture medium was pooled, dialysed and concentrated by Amicon ultrafiltration for intrauterine infusion. Serum proteins (SP) were obtained from blood collected from a Day 15 pregnant gilt and diluted for intrauterine infusion. Catheters were placed into both uterine horns or cyclic gilts (n = 8) on Day 10 of the oestrous cycle and uterine horns were ligated proximal to the uterine body. Gilts received either oestradiol valerate (E2) (5 mg) or corn oil (CO) on Days 11 and 12. On Days 12-14 each gilt received twice daily infusions of Day 15 pCSP in one uterine horn and SP in the other uterine horn.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

PubMed1990

Localization of an antiviral site on the pregnancy recognition hormone, ovine trophoblast protein 1.

Ovine trophoblast protein 1 (oTP-1) is the interferon alpha (IFN-alpha) variant with potent antiviral activity and low toxicity that is responsible for maternal recognition of pregnancy in sheep. To examine the structure/function basis for the potent antiviral activity of oTP-1, we have exploited the direct approach of synthetic peptide competition with oTP-1 for receptor, using N-terminal oTP-1-(1-37) and C-terminal oTP-1-(139-172) peptides. These peptides possess structures similar to those predicted for the intact molecule on the basis of circular dichroism. oTP-1-(1-37) at 1.5 mM specifically blocked oTP-1 antiviral activity without affecting the antiviral activity of natural ovine IFN-alpha, recombinant bovine IFN-alpha, and recombinant human IFN-alpha. At concentrations as low as 0.15 mM, oTP-1-(139-172) blocked the antiviral activity of oTP-1, as well as that of natural ovine IFN-alpha, recombinant bovine IFN-alpha, and recombinant human IFN-alpha, but not recombinant bovine interferon gamma. Further, binding of radiolabeled oTP-1 to endometrial membrane preparations could be effectively inhibited by polyclonal anti-C-terminal and anti-N-terminal antisera, with the anti-C-terminal antiserum being the more effective inhibitor. Consistent with peptide and antiserum functional data, oTP-1 and recombinant bovine IFN-alpha are predicted to possess similar C-terminal structure but different N-terminal structure by composite surface profile predictions. The findings suggest that the C-terminal regions of IFN-alpha s bind to a common site on the IFN-alpha receptor while the N-terminal region binds to a site unique for the particular IFN-alpha.

Amino Acid Sequence↗

PubMed1990

Oxytocin-stimulated inositol phosphate turnover in endometrium of ewes is influenced by stage of the estrous cycle, pregnancy, and intrauterine infusion of ovine conceptus secretory proteins.

Three experiments (Exp) assessed the influence of stage of the estrous cycle, pregnancy, and intrauterine infusion of ovine conceptus secretory proteins (oCSP) on turnover of inositol trisphosphate (the putative second-messenger for oxytocin-stimulated secretion of prostaglandin F2 alpha) in ovine endometrium during luteolysis and maternal recognition of pregnancy. In Exp 1, endometrium was collected from 5 cyclic (Cy) and 6 pregnant (P) ewes on Day 16 after onset of estrus. In Exp 2, endometrium was collected from Day 12 Cy (n = 5), Day 12 P (n = 3), Day 16 Cy (n = 4), and Day 16 P (n = 3) ewes. In Exp 3, 12 Cy ewes were allotted randomly, in a 2 x 2 factorial arrangement, to receive serum protein (SP), or oCSP and estradiol-17 beta (E2), or vehicle treatments. Ewes were injected i.v. with 0.5 mg E2 or vehicle on Day 12 and received twice-daily infusions of 1.5 mg SP or oCSP (containing 25 micrograms ovine trophoblast protein-1 by radioimmunoassay [RIA]) + SP (1.5 mg total protein) into each uterine horn on Days 12, 13, and 14. Blood samples for RIA of plasma progesterone were collected on Days 10-15 (before treatment on each day) and endometrium was collected on Day 15. For each Exp, 100 mg endometrium was incubated, in duplicate, for 2 h with 10 microCi [3H] inositol and treated with 0 or 100 nM oxytocin (OT) for 20 min, then [3H]inositol mono-, bis-, and trisphosphates (IP1, IP2, and IP3, respectively) were quantified.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Retinol-binding protein: a major secretory product of the pig conceptus.

Pig conceptuses and endometrial explants recovered from gilts between Days 10 and 15 of pregnancy were cultured in leucine-deficient or methionine-deficient medium supplemented with 3H-leucine or 35S-methionine, respectively, for 30 h. Conceptus and endometrial tissues from Day 15 of pregnancy were fixed in Bouin's fixative for immunocytochemistry and light microscopy. Conceptus culture medium from Day 15 of pregnancy was pooled, dialyzed, and fractionated by anion exchange and gel filtration chromatography. A family of 3-5 low molecular weight (Mr) acidic (Mr = 19,000-22,000; pI = 5.6-6.5) 3H-leu-labeled proteins were isolated and identified by two-dimensional polyacrylamide gel electrophoresis (2D-PAGE), electroblotting, and fluorography. The two major proteins (pCSP-1 and pCSP-2) were excised from a polyvinylidene difluoride transfer membrane, and NH2-terminal amino acids were sequenced. One peptide was sequenced through 33 amino acids and the second, which shared 100% homology, was sequenced through 22 amino acids. Analysis of the larger sequence indicated that it shared 93.9% and 90.9% homology with the first 33 amino acids of human and rabbit plasma retinol-binding protein (RBP), respectively. Analyses of culture medium from pig conceptus incubations by 2D-PAGE and immunoprecipitation with rabbit anti-human RBP serum indicated that immunoreactive RBP was produced between Days 10 and 15 of pregnancy and was present in Day 30 allantoic fluid. Western blotting of enriched fractions of Day 15 conceptus RBP followed by immunostaining indicated that five isoforms of radiolabeled RBP were present. Immunoreactive RBP was detected in trophectoderm and yolk sac of conceptuses and endometrial surface and glandular epithelium at Day 15 of pregnancy. Results from this study demonstrate that pig conceptuses secrete RBP prior to onset of conceptus elongation and throughout the peri-implantation period, which suggests that RBP and associated retinoids influence conceptus development.

Amino Acid Sequence↗

PubMed1990

Effect of pregnancy and exogenous ovarian steroids on endometrial prolactin receptor ontogeny and uterine secretory response in pigs.

During gestation, pigs have constant circulating levels of prolactin (PRL), and lack decidual PRL and placental lactogens. Effects of PRL on uterine physiology in pigs may be due to changes in endometrial PRL receptors. In this study, effects of the conceptus and cyclic hormonal environment on endometrial PRL receptors were investigated. Endometrial PRL receptor numbers were similar between Days 8 and 15 for cyclic gilts. In contrast, endometrial PRL receptor numbers for pregnant gilts were similar between Days 8 and 11, then increased (p less than 0.05) on Day 12 and remained elevated between Days 14 and 30. This day-by-status interaction approached significance (p less than 0.06) and overall receptor numbers were higher (p less than 0.01) for pregnant than for cyclic gilts. Pig conceptuses secrete estrogen between Days 11 and 12; therefore, regulation of endometrial PRL receptors by acute administration of estradiol was investigated. Uterine flushings and endometrium were collected from one uterine horn of cyclic gilts on Day 11; then, at 1, 6, 12, and 24 h following a single injection of estradiol valerate (EV; 5 mg, into adipose tissue), uterine flushings and endometrium were collected from the second uterine horn. Endometrial PRL receptor numbers were higher (p less than 0.05) at both 1 h and 6 h after treatment with EV and then decreased (p less than 0.02) by 12 h to below pretreatment values. In uterine flushings, total recoverable protein (p less than 0.05), uteroferrin (p less than 0.01), leucine aminopeptidase (p less than 0.05), calcium (p less than 0.03), sodium (p less than 0.01), and potassium (p less than 0.05) increased between 12 and 24 h following EV treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Ovine trophoblast protein-one inhibits development of endometrial responsiveness to oxytocin in ewes.

In experiment (Exp) 1, 12 cyclic ewes had catheters placed into each uterine horn on Day 7 (estrus = Day 0). On Days 11-15, 6 ewes received twice-daily intrauterine infusions of 1.5 mg serum protein (SP) into each uterine horn and 6 ewes received infusions of 1.08 mg SP + 0.42 mg ovine conceptus secretory proteins (oCSP) containing 25 micrograms ovine trophoblast protein-one (oTP-1) as determined by radioimmunoassay (25-35% bioactive by antiviral assay). SP-infused and oCSP-infused ewes had similar plasma 13,14-dihydro-15-keto prostaglandin F2 alpha (PGF2 alpha) profiles in response to oxytocin on Day 11, but SP ewes became more responsive (p less than 0.01) to oxytocin on Days 13 and 15 than oCSP ewes. SP ewes also had greater incorporation of [3H]inositol into inositol trisphosphate (IP3) (+3449%, p less than 0.01) and total inositol phosphate (IP) (+760%, p less than 0.08), in response to oxytocin, than did oCSP ewes (+553 and +168% for IP3 and total IP, respectively) in endometrium collected at ovariectomy/hysterectomy on Day 16. Mean CL weights on Day 16 and mean concentrations of progesterone in plasma collected at 12-h intervals on Days 6-16 were not different for SP and oCSP ewes, but concentrations of progesterone were lower (p less than 0.05) in SP ewes on Days 15-16 than for oCSP ewes. These results indicate that oTP-1 may prevent luteolysis by inhibiting development of endometrial responsiveness to oxytocin and, therefore, reduce oxytocin-induced synthesis of IP3 and PGF2 alpha.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Reorientation of prostaglandin F secretion by calcium ionophore, estradiol, and prolactin in perifused porcine endometrium.

Establishment of pregnancy in pigs requires a shift in endometrial prostaglandin (PG) F secretion from an endocrine (toward the myometrium and uterine vasculature) to an exocrine (toward the uterine lumen) orientation. Three experiments utilized bilateral endometrial perfusion devices for separate perifusion of myometrial and luminal surfaces to determine whether promoting calcium cycling across the luminal epithelial surface, which may be induced by interactive effects of estradiol and PRL, is involved in the reorientation of PGF secretion during establishment of pregnancy in pigs. In Exp 1, endometrium from cyclic gilts (n = 7) on day 14 after estrus was perifused with either saline (control) or calcium ionophore A23187 added to luminal surface perifusion buffer. In Exp 2, cyclic gilts (n = 7) at day 11 after estrus received an im injection of estradiol valerate (EV) after unilateral hysterectomy and the remaining EV-stimulated uterine horn removed at 6 h (n = 3) or 12 h (n = 4) after EV. Both surfaces of these endometrial samples were perifused with buffer containing either 250 ng/ml BSA or porcine PRL. In Exp 3, endometrium from cyclic (n = 3), pregnant (n = 4), and EV-induced pseudopregnant (n = 4) gilts was collected on day 14 after estrus and perifused with BSA or PRL to both surfaces. Orientation of PGF secretion was initially endocrine in Exps 1 and 2 (P less than 0.01). In Exp 1, calcium ionophore shifted the orientation of PG secretion from endocrine to exocrine (P less than 0.01). In Exp 2, neither EV in vivo nor PRL in vitro alone altered the orientation of PGF secretion. However, EV and PRL interacted to reorient secretion of PGF from endocrine to exocrine at 6 h (P less than 0.01) and 12 h (P less than 0.01) after EV. In Exp 3, the orientation of PGF secretion was endocrine in cyclic gilts and exocrine in pregnant and pseudopregnant gilts (status x side; P less than 0.05). PRL did not alter the orientation of PGF secretion regardless of reproductive status. These results suggest that the reorientation of endometrial PG secretion in pigs during the establishment of pregnancy involves interactive effects of estrogens and PRL, possibly through increased calcium cycling across the uterine epithelium.

Animals↗

PubMed1990

Hormonal regulation of insulin-like growth factor gene expression in pig uterus.

The present studies were undertaken to define potential regulation of endometrial insulin-like growth factor-I (IGF-I) synthesis and secretion by steroid hormones and to correlate conceptus- and serum-derived estrogens with these events. Four experimental groups of gilts were studied: 1) prepubertal gilts administered estradiol (E) and/or progesterone (P4) daily for up to 15 days; 2) mature gilts ovariectomized (ovx) on day 2 of the estrous cycle, and then administered E, P4, or E plus P4 from days 4-11 after estrus; 3) unilaterally pregnant gilts on day 12 or 16 after the onset of estrus; and 4) cyclic gilts administered E on day 11 and hysterectomized 1, 6, 12, or 24 h after E. IGF-I mRNA was measured by blot hybridization of total cellular RNAs, while a specific RIA was used to quantitate levels of tissue and uterine luminal fluid (ULF) IGF-I. In prepubertal gilts, E or P4 increased uterine IGF-I mRNA levels and IGF-I protein. Mature, ovx gilts treated with E, P4, or E plus P4 had increased levels of endometrial IGF-I mRNAs and protein and luminal IGF-I. The magnitude of E or P4 induction was comparable and was not additive. Gravid horns on day 12 had higher amounts of IGF-I in ULF compared to day 12 nongravid horns or day 16 gravid and nongravid horns. However, no significant differences in the amounts of endometrial IGF-I mRNA and tissue IGF-I content between horns on each day were detected. Acute treatment of cyclic gilts (day 11) with E increased levels of endometrial IGF-I mRNAs and luminal IGF-I 1 h after treatment. The effect of E was transient and was reversed within 24 h of E injection. IGF-II and IGF-binding protein-2 mRNAs were regulated by E and P4 distinct from IGF-I mRNAs. These results indicate that E and P4 are involved in the normal regulation of uterine IGF-I synthesis and/or secretion. However, the relative contributions of serum and conceptus-derived estrogens in these processes during the preimplantation period in the pig remain to be defined.

Aging↗

PubMed1990

Onset of secretion of proteins with antiviral activity by pig conceptuses.

In Exp. 1, antiviral activity was detected in Day-15 pregnant uterine flushings (6222 +/- 2167 units/ml) and in conceptus culture medium collected at 0, 1, 2, 4, 8, 16, 24, 32, 40, and 48 h (95, 375, 650, 1216, 1600, 2100, 2017, 2083, 3500 and 5000 units/ml, respectively; R2 = 0.81, P less than 0.01; y = 190.0 + 252.7x - 11.2x2 + 0.2x3. In Exp. 2, antiviral activity of Day-15 conceptus culture medium was reduced 99% after boiling for 20 min (P less than 0.01) and, after 18 h dialysis (6000-8000 Mr cut-off), 100% of the activity was in the retentate. In Exp. 3, antiviral activity was not detected in cultures of conceptuses from Days 10 and 11 and activity was maximal for Day 14 and Day 15 conceptuses (2100 and 2083 units/ml, respectively). Effects of day were best described by a quadratic regression equation (y = 17,652 - 3263x + 150x2; R2 = 0.55, P less than 0.01). In Exp. 4, changes in antiviral activity detected in uterine flushings from pregnant gilts on Days 8, 10, 11, 12, 14 and 15 (1.3, 0, 6.7, 63.3, 580 and 1663 units/ml, respectively) were described by the equation y = -20,743 + 6189x - 606x2 + 20x3 (R2 = 0.85, P less than 0.01). In Exp. 5, low antiviral activities (5-30 units/ml) were detected in all plasma samples collected from the uterine artery and uterine vein of pregnant and cyclic gilts, but values were not significantly influenced by pregnancy status, day or site of collection.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Influence of the endometrium, protease inhibitors and freezing on antiviral activity of proteins secreted by pig conceptuses.

In Exp. 1, only medium from cultures containing conceptus tissue had antiviral activity (P less than 0.05). Addition of Day-15 pregnant endometrium or Day-14 cyclic uterine flush proteins to cultures containing 200 mg conceptus tissue decreased antiviral activity (conceptus x endometrial protein interaction, P less than 0.06). Effects of endometrium (-54%) and uterine flush proteins (-40%) on antiviral activity of conceptus cultures did not differ from each other (P greater than 0.10). In Exp. 2, antiviral activity was only detected in cultures containing conceptus tissue (P less than 0.06). The amount of antiviral activity in cultures of Day-15 conceptus tissue was not influenced differently (P greater than 0.10) by culture in medium conditioned by endometrium from Day 10 or Day 12 of pregnancy. However, antiviral activity was undetectable in medium conditioned by endometrium from one of the Day-12 gilts. In Exp. 3, antiviral activity was present in medium from only 1 of 3 cultures from Day-12 gilts when assayed unfrozen. Antiviral activity was lower (P less than 0.01) in cultures of conceptuses from Day 12 than Day 14 of pregnancy; however, antiviral activity increased quadratically (P less than 0.05) when cultures contained 0, 0.01, 0.1 and 1.0 units/ml aprotinin, respectively. Freezing and thawing culture medium did not reduce (P greater than 0.10) antiviral activity compared to medium assayed unfrozen (1438 vs 1354 units/ml, respectively). These results suggest a regulatory influence of the endometrium on secretion of antiviral proteins by pig conceptuses in vitro.

Animals↗

PubMed1990

Evidence for steroid control of a putative angiogenic factor in the porcine uterus.

The formation of new capillaries, both in extraembryonic membranes and in the maternal endometrium, is an essential prerequisite for appropriate feto-maternal relationships throughout pregnancy. At present there is no indication of the nature of the uterine angiogenic stimulus. In-vitro, degradation products of hyaluronic acid, following its catalysis by hyaluronidase, have been shown to have angiogenic properties. In the current study, levels of hyaluronic acid in endometrial tissues and of hyaluronidase and hyaluronic acid in uterine flushings were measured during the oestrous cycle and early pregnancy. The concentration of both hyaluronic acid and hyaluronidase in uterine flushings followed the growth and regression of the corpus luteum, in that basal levels detected on days 0 and 6 increased to peak concentrations on days 12 and 15. By day 18, levels of both hyaluronidase and hyaluronic acid had decreased in cyclic gilts, but remained increased in pregnant pigs. Tissue concentrations of hyaluronic acid were not affected by pregnancy or by the day of the oestrous cycle. In a subsequent experiment, four groups of gilts were ovariectomized on day 4 and thereafter received daily injections of corn oil, progesterone, oestrogen or a combination of oestrogen and progesterone. Hyaluronidase was undetectable in uterine flushings collected on day 15 from corn oil- and oestrogen-treated gilts, but present in similar amounts in uterine flushings from gilts treated with progesterone and progesterone plus oestrogen. Similarly, uterine fluid concentrations of hyaluronic acid were increased in progesterone- and progesterone plus oestrogen-treated gilts, but not in corn oil- or oestrogen-treated pigs. Tissue concentrations of hyaluronic acid were unaffected by steroid treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiogenesis Inducing Agents↗

PubMed1990

Endometrial inositol phosphate turnover in pigs is reduced during pregnancy and estradiol-induced pseudopregnancy.

Three experiments were conducted to examine inositol phosphate (IP) turnover in response to treatments applied in vitro to endometrium from cyclic (CYC), pregnant (PREG) and estradiol-induced pseudopregnant (PSP) gilts. In Exp. 1, treatments (in 25 microliters .1 M NaHCO3) were 1) control (NaHCO3), 2) 125 ng oxytocin, 3) .25 micrograms prolactin, 4) 2.5 micrograms prolactin and 5) 5 micrograms pig conceptus secretory proteins (pCSP). Basal IP turnover on d 14 (estrus = d 0) for CYC was 3.9 to 5.0-fold greater than for PREG gilts and .6 to 1.1-fold greater than for PSP gilts (P less than .05). Oxytocin increased IP turnover 23 to 42% in CYC gilts (P less than .05), but not in PREG or PSP gilts. The treatment x reproductive status interaction (P less than .05) indicated that pCSP increased IP turnover 74 to 140% in PREG gilts but decreased it 18 to 22% in CYC and 17 to 50% in PSP gilts. In Exp. 2, treatments were applied in a 2 x 2 x 2 arrangement: 1) 0 or 125 ng oxytocin; 2) 0 or 2.5 micrograms prolactin and 3) 0 or 5 micrograms pCSP. Basal IP turnover on d 14 was 3.3 to 5.4-fold greater (P less than .05) in CYC than in PSP gilts and was affected by interaction (P less than .05) of pCSP and prolactin. Inositol phosphate turnover was increased by prolactin (12 to 22%) and by pCSP (7 to 34%) but, when combined, the stimulatory effects of each were eliminated.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

Effect of fructose consumption during lactation on sow and litter performance and sow plasma constituents.

The effects of dietary consumption of high-fructose corn syrup (HFCS) and dextrose during a 28-d lactation on sow and litter performance and sow plasma constituents were examined in 45 multiparous and 36 primiparous crossbred sows. Isocaloric and isonitrogenous corn-soybean meal diets were formulated to contain either 20% fructose or 20% glucose. Diets were fed on a metabolic BW basis from d 0 to d 28 of lactation. Litter and pig weights on d 28 were not affected (P greater than .05) by treatment. Litter size was greater (P less than .10) at weaning for primiparous sows fed HFCS, but multiparous sows weaned heavier (P less than .05) pigs. Sow weight change during lactation was not influenced by diet, but primiparous sows lost more (P less than .05) weight during lactation and had longer intervals to estrus than multiparous sows did. Milk yields on d 17 and 21 of lactation were not different (P greater than .05) for sows fed HFCS vs dextrose, but sows fed HFCS tended to have greater (P = .05) percentage of milk fat. Preprandial concentrations of fructose in plasma were low in sows fed HFCS and nondetectable in those fed dextrose but were elevated (P less than .05) after consumption of HFCS. Conversely, similar (P greater than .05) concentrations of glucose in plasma preprandially were followed by greater (P less than .05) postprandial glucose concentrations in sows fed dextrose. Although postprandial concentrations of insulin were not affected (P greater than .05) by diet, sows fed dextrose had greater (P less than .05) preprandial insulin concentrations in plasma. Concentrations of nonesterified fatty acids and growth hormone in plasma and response to a glucose challenge were not affected (P greater than .05) by feeding HFCS. However, concentrations of insulin in plasma following glucose infusion were less (P less than .05) during the glucose challenge period on d 25 than on d 13 of lactation.

Animals↗

PubMed1989

Structural relationship, biosynthesis, and immunocytochemical localization of uteroferrin-associated basic glycoproteins.

Uteroferrin, a progesterone-induced secretory protein of the pig uterus, can noncovalently associate with additional progesterone-induced glycoproteins (uteroferrin-associated glycoproteins or UfAP) to form a heterodimer. The UfAP were dissociated from uteroferrin by passage through an immunoaffinity column. The flow through material consisted of two immunologically related variants of different size (Mr = 47,000-50,000 and Mr = 39,000-40,000) forms. By using an antiserum to all molecular weight components of the UfAP, it was shown that these glycoproteins were localized in the glandular epithelium of the uterus. Amino acid sequence analysis of the higher molecular weight (Mr = 47,000-50,000) form indicated it had a common amino-terminal sequence which was distinct from that of the lower molecular weight (Mr = 39,000-40,000) form. Endoglycosidase F treatment converted the Mr = 47,000-50,000 form to a common product with Mr = 43,000. Tryptic peptide analysis showed that the Mr = 39,000-40,000 form was closely related in primary sequence to the larger species. When endometrial RNA was translated in vitro, a single major product (Mr = 45,000) was immunoprecipitated by using the UfAP antiserum. These results suggest that the different forms of the UfAP originate from a single precursor by differential glycosylation and peptide cleavage. Endometrial explant cultures released all forms of the glycoproteins. When [32P]orthophosphate was provided, label was incorporated into the 6-position of D-mannosyl residues on the oligosaccharide chains of the UfAP. Therefore the associated glycoproteins have a structural feature normally associated with lysosomal enzymes.

Acid Phosphatase↗

PubMed1989

De novo synthesis and release of polypeptides from cyclic and early pregnant porcine oviductal tissue in explant culture.

The objective of the present study was to identify and characterize in a limited manner the major de novo oviductal secretory proteins (OSP) synthesized and released by the porcine oviduct. Oviductal tissue was collected on various days of the estrous cycle (EC) and early pregnancy (EP) and cultured in a modified minimal essential medium supplemented with 100 muCi L-[3H]-leucine. Oviductal secretory activity, as measured by the rate of incorporation of 3H-leucine (dpm/mg wet tissue weight) into nondialyzable macromolecules, was greatest (P less than .01) between days 0 and 2 and reached its lowest levels on days 10 to 15. There was no difference between left and right side or pregnancy status. This increased rate of incorporation at proestrus and estrus is temporally associated with elevated levels of estrogen. Incorporation rate for ampulla was greater than for the isthmus. Analysis of oviductal culture medium by one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis and fluorography revealed three protein bands of relative molecular weight (Mr) 335,000, 115,000, and 85,000, which were associated with proestrus, estrus, and metestrus and were not detectable on other days. All three proteins also incorporated 3H-glucosamine. The 115,000 Mr band was the major 3H-glucosamine-labeled protein. Two protein bands (Mr 60,000 and 20,000) were expressed with increasing progesterone during diestrus. Other de novo synthesized protein bands appear to be present throughout the EC and EP with little modulation by estrogen or progesterone. Thus, this study demonstrates that for the porcine oviduct, the increase in the incorporation rate of 3H-leucine into OSP by both whole oviduct and ampulla and de novo synthesis and secretion of three glycoproteins, Mr 335,000, 115,000, and 85,000, were associated with proestrus and estrus when events such as fertilization and early cleavage stages of embryo development occurred.

Animals↗