Biomedical subjects

A Miyake

Publications and source records attributed to A Miyake.

At least 163 records · Page 9Linked to original sources

PubMed1993

High magnesium concentration inhibits ligand-stimulated calcium influx and hormone secretion in rat pituitary lactotropes with involvement of intracellular free magnesium.

The effects of extracellular magnesium concentration ([Mg2+]ex) on thyrotropin-releasing hormone (TRH)-stimulated intracellular free calcium mobilization and prolactin secretion were investigated concomitantly with measurement of the intracellular free magnesium concentration ([Mg2+]i). TRH-stimulated intracellular free calcium mobilization was significantly inhibited when the medium was replaced by high Mg2+ medium ([Mg2+]ex = 10 mM) in normal Ca2+ medium. The inhibitory effects of high Mg2+ became apparent concomitantly with an increase in [Mg2+]i from 0.7 to 1.3 mM. High Mg2+ significantly inhibited TRH-induced PRL secretion in a dose-dependent manner in normal Ca2+ medium. TRH-stimulated inositol triphosphate (IP3) production was rather augmented by the replacement with high Mg2+ medium. In summary, high Mg2+ inhibits Ca2+ influx stimulated by TRH in the rat pituitary lactotropes, possibly with the involvement of [Mg2+]i increase. These results have general importance in relation to high Mg(2+)-induced suppression of the biological functions of cells.

Animals↗

PubMed1993

Dynamics of exocytosis, endocytosis and recycling in single pituitary gonadotropes.

The dynamic changes in exocytosis, endocytosis and recycling in single gonadotropes induced by gonadotropin-releasing hormone (GnRH) were visualized and estimated with an impermeable fluorescent membrane probe, 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatrien (TMA-DPH), using a digital imaging and confocal laser scanning microscope. 10(-7) M GnRH induced exocytosis and endocytosis within 10 sec and 60 sec, respectively. Recycling of the plasma membrane started at 180-300 sec. Exocytosis and endocytosis in purified gonadotropes changed dose-dependently with 10(-10)-10(-7) M GnRH. These results show that GnRH-induced exocytosis, endocytosis and recycling in gonadotropes maintain dynamic equivalence. The procedure we established will be very useful in studies of the function of secretory cells.

Animals↗

PubMed1993

Autocrine growth mechanism by transforming growth factor (TGF)-beta 1 and TGF-beta 1-receptor regulation by epidermal growth factor in a human endometrial cancer cell line IK-90.

Transforming growth factor-beta 1 (TGF-beta 1) enhanced cell proliferation in a concentration-dependent manner in a human endometrial cancer cell line, IK-90. Scatchard analysis of TGF-beta 1 receptor in IK-90 cells, using 125I-TGF-beta 1 as a ligand, revealed the presence of a class of high-affinity TGF-beta 1 receptors (2,000 sites per cell, KD = 74pM). Moreover, IK-90 cells produced and secreted TGF-beta 1: TGF-beta 1 messenger RNA was detected at 2.5 and 4.0 kb by Northern-blot analysis using 32P-labeled TGF-beta 1 cDNA as a probe, and TGF-beta 1 activity in conditioned medium by the inhibition of 3H-thymidine uptake into CCl 64 mink lung epithelial cells. We investigated the regulation of TGF-beta 1 receptor by 4 kinds of growth factor: epidermal growth factor (EGF) but not TGF-beta 1, insulin or insulin-like growth factor-1 increased the level of TGF-beta 1 binding sites in a concentration- and time-dependent manner. These findings suggest that TGF-beta 1 may be a potential autocrine growth factor in a human endometrial cancer cell line IK-90 and that this autocrine mechanism may be affected by EGF.

Adult↗

PubMed1993

Ovariectomy increases the level of estrogen receptor mRNA and estrogen receptor binding sites in female rat adipose tissue.

The roles of estrogen in the changes in estrogen receptor (ER) mRNA and ER binding sites in rat adipose tissue were studied in female rats. To elucidate the mechanism(s) behind ovariectomy (OVX)-induced obesity, the levels of ER mRNA and ER binding sites in adipose tissue were analyzed three weeks after OVX using Northern blot analysis of ER mRNA and the [3H]E2 binding assay, respectively. OVX induced an increase in body weight, and replacement of estradiol (E2) prevented that increase. Significant increases in the amounts of ER mRNA and in [3H]E2-specific binding were observed after OVX, and E2 replacement reduced both of those increases. These results suggest that E2 may regulate rat obesity directly through ER in adipose tissues.

Adipose Tissue↗

PubMed1993

Magnesium sulfate inhibits oxytocin-induced calcium mobilization in human puerperal myometrial cells: possible involvement of intracellular free magnesium concentration.

OBJECTIVE: Our purpose was to elucidate the mechanisms of the tocolytic action of Mg2+ on the human myometrium. STUDY DESIGN: The effects of extracellular Mg2+ on oxytocin-induced increases in the intracellular free Ca2+ concentration in human puerperal myometrial cells were examined by means of indo-1-AM. The changes in the intracellular free Mg2+ concentration under various conditions were also measured with Mg(2+)-fura-2-AM. RESULTS: The increase in intracellular free Ca2+ concentration induced by oxytocin was reduced to 26% of that in the normal solution 20 minutes after replacement of the normal solution with an extracellular Mg2+ solution, 10 mmol/L. When extracellular Ca2+ was removed, the increase in intracellular free Ca2+ concentration was not suppressed even 20 minutes after the replacement. A solution of extracellular Mg2+ concentration, 10 mmol/L, raised the intracellular free Mg2+ concentration gradually, by approximately 150% in 20 minutes, concomitant with the suppression of the response to oxytocin in the intracellular free Ca2+ concentration. CONCLUSION: High intracellular free Mg2+ concentration, caused by high extracellular Mg2+, is essential for suppression of oxytocin-induced Ca2+ influx across the cell membrane; this presumably results in inhibition of uterine contractions.

Calcium↗

PubMed1993

Suppression of inflammatory responses to 12-O-tetradecanoyl-phorbol-13-acetate and carrageenin by YM-26734, a selective inhibitor of extracellular group II phospholipase A2.

1. YM-26734 [4-(3,5-didodecanoyl-2,4,6-trihydroxyphenyl)-7-hydroxy-2-(4-hydroxyph eny l) chroman] dose-dependently inhibited the activities of extracellular phospholipase A2 (PLA2): rabbit platelet-derived group II and porcine pancreas-derived group I PLA2, with IC50 values of 0.085 (0.056-0.129, n = 5) and 6.8 (5.0-9.6, n = 5) microM, respectively. 2. In contrast, YM-26734 did not reduce the activity of intracellular PLA2 prepared from mouse macrophages, which preferentially hydrolyzed arachidonoyl phospholipids at concentrations up to 50 microM. YM-26734 also showed no effect against either sheep seminal vesicle cyclo-oxygenase or rat leukocyte 5-lipoxygenase. 3. Linewater-Burk analysis showed that YM-26567-1 behaved as a competitive inhibitor of group II PLA2 derived from rabbit platelets, with a Ki value of 48 nM. 4. In mice, YM-26734 inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA, 1 microgram/ear)-induced ear oedema in a dose-dependent manner, with ED50 values of 45 (30-67) micrograms/ear (n = 5) and 11 (4-32) mg kg-1, i.v. (n = 5), but did not decrease arachidonic acid (4 mg/ear)-induced ear oedema at 1 mg/ear and 30 mg kg-1, i.v. 5. In rats, the accumulation of exudate fluids and leukocytes in the pleural cavity in response to carrageenin injection (2 mg) was significantly less in a group treated with YM-26734 (20 mg kg-1, i.v.) than in the control group (0.43 +/- 0.02 vs 0.59 +/- 0.03 g per cavity and 3.8 +/- 0.2 vs 4.9 +/- 0.3 x 10(7) cells per cavity, respectively; n = 5). 6. These results suggest that YM-26734 is a potent and competitive inhibitor of extracellular PLA2 with selectivity for group II PLA2, and that the inhibition of group II enzymes activity may cause the suppression of inflammatory responses to TPA and carrageenin.

Animals↗

PubMed1993

Involvement of epidermal growth factor in inducing obesity in ovariectomized mice.

Ovariectomy (Ovx) of mice significantly increases the epidermal growth factor (EGF) concentration in the submandibular gland. To elucidate the role of this elevated EGF in obesity of Ovx mice, we examined the effects of sialoadenectomy (Sx) and anti-EGF rabbit antiserum administration on the body weight (BW) gain and carcass fat deposition in Ovx animals. Studies were performed in four groups of mice consisting of control, Ovx, Ovx+Sx, and Ovx+anti-EGF groups. Ovx increased the BW gain compared with the control animals, whereas Sx and anti-EGF significantly reduced it. Although the relative weights (weight ratio to BW) of the liver and kidney were not significantly changed by Ovx, Sx, or anti-EGF treatment of Ovx mice, the relative weights of mesenteric, parametrial, and subcutaneous fat tissues were increased in Ovx mice, and this increase was significantly reduced by Sx or anti-EGF administration. Ovx induced adipocyte hypertrophy, and this effect was eliminated by Sx and anti-EGF. Moreover, acyl-CoA synthetase mRNA level was increased by Ovx, and this increase was reduced by Sx and anti-EGF in mesenteric fat tissue. These findings suggest that elevation of EGF may play a role in the induction of obesity in Ovx mice.

Acetate-CoA Ligase↗

PubMed1993

Intraventricular administration of histidyl-proline-diketopiperazine [Cyclo(His-Pro)] suppresses prolactin secretion and synthesis: a possible role of Cyclo(His-Pro) as dopamine uptake blocker in rat hypothalamus.

Histidyl-proline-diketopiperazine [Cyclo (His-Pro) (CHP)] was discovered to be one of the metabolites of TRH. To understand the specific role of CHP in rat hypothalamic dopamine neurons, we examined the in vivo effects of intraventricular (icv) infusion of CHP on the release and synthesis of PRL in the rat pituitary and the 3,4-dihydroxyphenylacetic acid (DOPAC)/dopamine ratio in the rat hypothalamus. We also examined the in vitro effects of CHP on the release of [3H]dopamine from dispersed tuberoinfundibular dopamine neurons, [3H]dopamine reuptake in hypothalamic membrane fractions, and PRL release from rat pituitary cultured cells. Female rats were treated by icv infusion of 1 microM CHP daily for 1, 3, and 7 days, using Alzet osmotic pumps. After 1 day of treatment, the serum PRL concentration was significantly decreased. Northern blot analysis of the total RNA isolated from the pituitary glands of control animals using 32P-labeled PRL cDNA as a probe indicated the presence of PRL gene transcript, 1.0 kilobase in size, and its amount was decreased by CHP treatment. CHP did not affect [3H]dopamine release from dispersed tuberoinfundibular dopaminergic neurons at any concentration up to 1 microM. CHP did not inhibit PRL release from cultured pituitary cells at low concentrations (1-100 nM), but it stimulated PRL release at high concentrations (1 and 10 microM). We also examined the concentrations of dopamine and DOPAC in the rat hypothalamus when CHP was administered icv for 1 or 7 days. There was a significant decrease in the DOPAC/dopamine ratio after CHP treatment for 1 day. Furthermore, CHP caused dose-dependent inhibition of [3H]dopamine uptake by the rat hypothalamus similar to other dopamine uptake blockers, such as benztropine and GBR12909. These data suggest that icv administration of CHP might decrease both PRL secretion and accumulation of PRL gene transcripts in the pituitary by decreasing the DOPAC/dopamine ratio and inhibiting dopamine reuptake in the rat hypothalamus.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1993

Menstrual stage-specific expression of epidermal growth factor and transforming growth factor-alpha in human oviduct epithelium and their role in early embryogenesis.

We studied the expression of epidermal growth factor (EGF) and transforming growth factor (TGF)-alpha in human oviduct epithelium at various menstrual stages. Immunohistochemical stainings using anti-EGF and anti-TGF alpha antibodies showed a specific staining in ampullary oviduct epithelium at late follicular and luteal stages, but the stainings were very weak at early follicular stage. Quantitative reverse transcription and polymerase chain reaction, using beta-actin messenger RNA as an internal standard, revealed the menstrual stage-specific expression of EGF and TGF alpha gene transcripts: relative amounts of EGF and TGF alpha messenger RNA to those of beta-actin were 1.5 +/- 1.9% (mean +/- SD) and 1.4 +/- 0.6% (n = 3) at early follicular, 16.5 +/- 4.9% and 12.6 +/- 2.6% (n = 3) at late follicular, and 18.9 +/- 2.2% and 13.8 +/- 3.2% (n = 3) at luteal stages, respectively. The expression of these growth factors was in proportion to the increase in serum estradiol but not to progesterone levels. To clarify the biological significance of these growth factors, mouse two-cell embryos were cocultured with human oviduct epithelial cells with or without blocking the action of these growth factors. Cocultures significantly promoted blastocyst formation, but this promotive effect of the oviduct epithelial cells was completely abolished by the addition of anti-EGF and/or anti-TGF alpha monoclonal neutralizing antibodies to the coculture system. All these results showed that EGF and TGF alpha were synthesized and expressed in human oviduct epithelium specifically to menstrual stages, and that these growth factors may be involved in early embryonic development.

Actins↗

PubMed1993

Pituitary folliculo-stellate-like cell line (TtT/GF) responds to novel hypophysiotropic peptide (pituitary adenylate cyclase-activating peptide), showing increased adenosine 3',5'-monophosphate and interleukin-6 secretion and cell proliferation.

Several studies have shown that folliculo-stellate cells (FS cells) in the anterior pituitary gland exhibit paracrine functions. Recently, we established a pituitary FS-like cell line, TtT/GF, which was derived from an isologously transplantable pituitary thyrotropic tumor line induced by radiothyroidectomy. In studies to examine the function of FS cells, we found that two forms of a novel hypophysiotropic peptide, pituitary adenylate cyclase-activating polypeptide (PACAP), were potent activators of TtT/GF cells. Both the 27- and 38-amino acid forms of PACAP (PACAP-27 and PACAP-38) and vasoactive intestinal peptide (VIP) increased the levels of cAMP in TtT/GF cells in a similar dose-dependent manner. PACAP-27 and PACAP-38 specifically stimulated the proliferation of TtT/GF cells dose dependently, whereas VIP was ineffective. The minimal effective concentration of the PACAPs inducing cell proliferation was between 10(-8)-10(-7) M. However, PACAP-27 was much less potent than PACAP-38 in stimulating cell proliferation and DNA synthesis. PACAP-38, PACAP-27, and VIP all stimulated the release of interleukin-6 (IL-6) from TtT/GF cells. PACAP 38 (10(-8) M) stimulated IL-6 production effectively within 1 h of incubation, and the level attained at 8 h of cultivation (620 pg/ml) was nearly 10-fold that in the absence of PACAP-38 (60 pg/ml). PACAP-38 and VIP stimulated IL-6 secretion significantly at 10(-10)-10(-9) M in a bell-shaped manner; the maximum values were 10(-7) and 10(-8) M, respectively. On the other hand, IL-6 secretion stimulated by PACAP-27 became saturated at 10(-8) M, and the maximum value (320 pg/ml) was about 25% of that stimulated by PACAP-38 (1280 pg/ml). These findings obtained using TtT/GF cells as a model of FS cells suggest that PACAP acts as a hypophysiotropic factor, which targets FS cells and stimulates their proliferation, adenylate cyclase activation, and IL-6 secretion.

Animals↗

PubMed1993

Prolactin stimulates [3H]dopamine release from dispersed rat tubero-infundibular dopaminergic neurons and dopamine decreases gonadotropin-releasing hormone release induced by calcium ionophore.

In order to investigate the involvement of prolactin-dopamine and dopamine-gonadotropin interactions in the hypothalamo-pituitary axis of hyperprolactinemia, in vitro studies were performed using primary cultures of dispersed rat hypothalamic heterogeneous cells containing tubero-infundibular dopaminergic neurons or gonadotropin-releasing hormone (GnRH) neurons. We observed that prolactin caused dose-dependent stimulation of [3H]dopamine release after a 16-h incubation. Staurosporin (10 nmol/l), an inhibitor of protein kinase C, significantly reduced the [3H]dopamine release induced by prolactin (1 mg/l). Incubation of tubero-infundibular dopaminergic neurons with prolactin (1 mg/l) had no effect on intracellular cyclic adenosine monophosphate accumulation. Dopamine (1 mumol/l) significantly (p < 0.01) reduced the release of GnRH induced by 50 mumol/l calcium ionophore from dispersed hypothalamic cells from the preoptic area, while prolactin had no effect on GnRH release. These data support the hypothesis that the antigonadotropic effect of prolactin on the hypothalamus is mediated by an inhibitory effect of dopamine on GnRH release.

Animals↗

PubMed1993

Imaging of peritoneal pseudocysts: value of MR imaging compared with sonography and CT.

OBJECTIVE: Peritoneal pseudocysts are created when fluid arising from the ovary is trapped by peritoneal adhesions. We studied the value of MR imaging, compared with sonography and CT, for detecting these abnormalities. SUBJECTS AND METHODS: Nine women, 27 to 49 years old, who had surgically proved peritoneal pseudocysts were included in the study. All nine patients were premenopausal, and eight had a history of pelvic surgery. All patients were examined with MR imaging and sonography, and five were also examined with CT. Imaging findings were analyzed and compared with the surgical findings. RESULTS: Sonograms in all nine patients showed a thick-walled cyst that contained focal echoes indicating nodules, making it difficult to differentiate these lesions from cystic ovarian tumors. In eight of the nine patients, the fluid in the pseudocysts had low signal intensity on T1-weighted MR images and high signal intensity on T2-weighted spin-echo MR images, suggesting that the fluid was serous. The pseudocyst had an irregular shape on MR images in seven patients and on CT scans in three patients. However, MR provided more information than CT did about the nature of the fluid within the pseudocyst. CONCLUSION: Our study suggests that MR imaging is more useful than sonography and CT for determining the characteristic findings of peritoneal pseudocysts.

Adult↗

PubMed1992

Activin A increases cytosolic free calcium concentration in rat pituitary somatotropes.

The effect of activin A on the cytosolic free calcium concentration ([Ca2+]i) in normal rat pituitary cells was examined using a calcium sensitive fluorescent dye, indo 1 AM, and a digital imaging fluorescent microscope system. The cells showing an increase in [Ca2+]i in response to activin A were then characterized by comparison with cells responding to growth hormone releasing hormone (GRH), thyrotropin releasing hormone (TRH), corticotropin releasing hormone (CRH), and gonadotropin releasing hormone (GnRH) in monolayer cultures of normal rat pituitary cells. Activin A increased [Ca2+]i in some cells in a mixed population of normal rat pituitary cells. The cells that responded to activin A also responded to GRH. Most of these cells were not affected by other tropic hormones (CRH, TRH, and GnRH), but a few cells responded to both GRH and TRH. None of the activin A-responding cells responded to CRH or GnRH, and none of the CRH- or GnRH-responding cells responded to activin A. In a preparation of somatotropes purified 80-90% by fluorescence-activated cell sorting, activin A increased [Ca2+]i in 30% of the cells that shows a [Ca2+]i-response to GRH. These findings suggest direct involvement of somatotropes in activin A-induced biological events in the rat pituitary gland.

Activins↗

PubMed1992

Relationship of age at menarche and subsequent fertility.

We investigated retrospectively the relationship between the age at menarche and reproductive ability in 2278 married women. Those who had a pregnancy experienced menarche at a mean age (+/- SEM) of 13.7 +/- 0.1 years, and those who were infertile had menarche at a mean age of 14.0 +/- 0.2 years, difference in the times of onset of menarche being significant (P less than 0.05). Moreover, a group in whom menstruation started after the age of 18 years had a significantly higher rate of infertility (15.7%) than the others (5.0%). Irregular menstruations during the first few years after menarche was also related to decreased reproductive ability. These findings indicate the importance of menarche before the age of 18 for normal reproductive functioning.

Adolescent↗

PubMed1992

Regulation of intracellular Mg2+ by superoxide in amnion cells.

Changes of intracellular free Mg2+ concentration ([Mg2+]i) in human amnion cells induced by superoxide anion were determined using a highly Mg(2+)-sensitive fluorescent dye Mg(2+)-fura2 or Mg(2+)-indol. Superoxide anion, produced by addition of xanthine oxidase to hypoxanthine, induced decrease of [Mg2+]i. The decrease was significantly inhibited by an anion channel blocker, 4,4'diisothiocyano-2,2' disulfonic acid stilbene (DIDS). Superoxide dismutase (SOD), injected into cells by cell fusion, also inhibited the change of [Mg2+]i, but catalase did not. Superoxide anion induced prompt increase of intracellular pH (pHi) as well as decrease of [Mg2+]i and subsequently activated the increase of intracellular free Ca2+ ([Ca2+]i) and the release of arachidonate. In contrast to superoxide anion, NH4Cl which induces increase of pHi in amnion cells increased [Mg2+]i. The elevation of basal level of [Mg2+]i by Mg(2+)-ionophore inhibited the change of [Ca2+]i and the release of arachidonate induced by superoxide anion. These results suggest that superoxide anion, transported through anion channels into cells, decreases [Mg2+]i directly, not due to a pH-effect and that the decrease of [Mg2+]i may regulate biological functions of the cells via increase of [Ca2+]i.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗

PubMed1992

Triplet pregnancy involving complete hydatidiform mole and two fetuses: genetic analysis by deoxyribonucleic acid fingerprint.

A case of a triplet pregnancy involving a dizygous twin pregnancy and a complete hydatidiform mole after therapy with human menopausal gonadotropin and human chorionic gonadotropin is reported. Two female fetuses, two placentas in one mass with two amnions and two chorions, and a tumor mass with a grapelike appearance were spontaneously delivered at 19 weeks of gestation. The deoxyribonucleic acid fingerprints of the two placentas and tumor tissue were compared with those of the parents. The fingerprints of the placentas showed patterns different from each other; however, all their polymorphic fragments could be traced back to either the father or mother. All polymorphic fragments of the tumor tissue were inherited only from the father (androgenesis). These results indicated that this triplet pregnancy involved a dizygous twin pregnancy and a complete hydatidiform mole.

Adult↗

PubMed1992

In vitro and in vivo activities of SCE-2787, a new parenteral cephalosporin with a broad antibacterial spectrum.

SCE-2787, a new cephalosporin having a condensed azolium moiety in the 3 position and an aminothiadiazolyl group in the 7 beta side chain, was evaluated for its in vitro and in vivo activities in comparison with those of ceftazidime, flomoxef, cefpirome, and E1040. Against methicillin-susceptible strains of Staphylococcus aureus and Staphylococcus epidermidis, SCE-2787 was more active than ceftazidime and E1040 and was as active as flomoxef and cefpirome, with MICs for 90% of strains tested (MIC90s) being 1.56 micrograms/ml or less. SCE-2787 was also active against Pseudomonas aeruginosa, for which the MIC90 was 6.25 micrograms/ml, which was lower than that of cefpirome and comparable to that of ceftazidime. SCE-2787 was marginally active against methicillin-resistant strains of staphylococci and Enterococcus faecalis, although its MIC90s were the lowest among those of the antibiotics tested. The activities of SCE-2787 against Streptococcus species, most members of the family Enterobacteriaceae, and Haemophilus influenzae exceeded those of ceftazidime and flomoxef and were comparable to those of cefpirome. Furthermore, MIC90s of SCE-2787 were significantly lower than those of ceftazidime for ceftazidime-resistant isolates of Citrobacter freundii and Enterobacter cloacae. SCE-2787 was resistant to hydrolysis by various types of beta-lactamases, including the Bush group 1 beta-lactamases, and had low affinities for these enzymes, with Km or Ki values of greater than 100 microM. The in vitro activity of SCE-2787 was reflected in its efficacy in mouse protection tests. Thus, SCE-2787 appears to be a promising cephalosporin that should be further evaluated in clinical trials.

Animals↗

PubMed1992

Binding sites for interleukin-6 in the anterior pituitary gland.

Interleukin-6 (IL-6) binding site in the rat anterior pituitary gland was characterized using radioiodinated human recombinant (hr) IL-6. Results showed that the anterior pituitary gland contained 170 binding sites per cell of a single class with a dissociation constant of 2.7 x 10(-9) M. The binding of 125I-hrIL-6 to the rat anterior pituitary gland was competitively inhibited by unlabeled hrIL-6, but not by hrIL-1 alpha, hrIL-1 beta, hrIL-2 or hr-interferon-gamma, indicating these binding sites are specific for IL-6. We also demonstrated mouse IL-6 receptor gene expression in the rat anterior pituitary gland by Northern blot analysis. Furthermore, the IL-6 receptor was detected on human gonadotrophs by the double immunofluorescence method. Our findings demonstrate the presence and expression of IL-6 binding site in the rat anterior pituitary gland and the presence of IL-6 binding site on human gonadotrophs, suggesting the important role of IL-6 binding site in pituitary hormone release in both species.

Animals↗