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PubMed1992

Onset and characteristics of the midcycle surge in bioactive and immunoactive luteinizing hormone secretion in normal women: influence of physiological variations in periovulatory ovarian steroid hormone secretion.

Limited studies in nonhuman primates suggest that the midcycle LH surge is characterized by distinctly different patterns of bioactive (LH-BIO) and immunoactive (LH-RIA) LH secretion. To further examine the patterns of midcycle LH-BIO and LH-RIA secretion and explore the influence of physiological variations in steroid hormone feedback on LH surge dimensions we studied seven normal ovulatory women over the periovulatory interval. In each, blood samples were obtained every 3 h and transvaginal ultrasonography was performed every 12 h over a 5-7 day interval at midcycle. Serum levels of LH-RIA, FSH, estradiol (E2), progesterone (P4), and 17-hydroxyprogesterone were determined by RIA; LH-BIO was estimated using a mouse leydig cell bioassay. Hormone data were standardized to the time of surge onset in LH-RIA (time zero), defined as a 100% increase above a 6-point running mean baseline value; surge cessation was defined as a decline to below baseline concentration. Mean LH-RIA surge duration was 54.0 +/- 4.0 h. LH-BIO surge onset was simultaneous with that of LH-RIA and coincident with the peak in E2 levels (mean data). Mean P4 and 17-hydroxyprogesterone rose in a parallel, phasic manner, an abrupt increase in slope occurred between -6 h and +30 h but an acute rise in P4 was not consistently observed among individuals. The surge onset to follicle rupture interval (mean 37.6 +/- 4.2 h) positively correlated with peak LH-RIA (r = 0.76, P less than 0.05), surge amplitude (r = 0.74, P less than 0.05) and surge onset to peak interval (r = 0.87, P less than 0.02), but not surge duration. There were no significant relationships between E2 or P4 (mean, peak, integrated, slope) and surge amplitude or duration (LH-RIA, FSH), peak value, or surge onset to peak interval (LH-RIA, LH-BIO, FSH). These data suggest that in women, 1) onset of the midcycle surge in LH-RIA and LH-BIO is simultaneous, and 2) surge characteristics are not influenced by physiological variations in steroid hormone secretion that occur beyond the thresholds required for surge initiation.

Adult↗
PubMed1993

Cushing's disease in a child caused by a corticotropin-releasing hormone-secreting intrasellar gangliocytoma associated with an adrenocorticotropic hormone-secreting pituitary adenoma.

Cushing's disease resulting from intrasellar corticotropin-releasing hormone (CRH)-secreting gangliocytomas is very rare, and only two such cases have been reported in the literature to date. The authors present a third case in which an adrenocorticotropic hormone-secreting pituitary adenoma was found in addition to a gangliocytoma in a 10-year-old girl with clinical and endocrinological symptoms of Cushing's disease. Computed tomographic and magnetic resonance imaging scans showed a suprasellar and parasellar tumor. A green-colored, heterogeneous tumor and a small adenoma were removed transsphenoidally. Histological examination revealed a large gangliocytoma immunoreactive for CRH and a small, mucoid cell pituitary adenoma immunoreactive for ACTH. This is the first case of such a tumor causing Cushing's disease in a child. It might exemplify induction of an ACTH-secreting pituitary adenoma by means of chronic overstimulation of CRH.

Adenoma↗
PubMed2007

The maturation of mucus-secreting gastric epithelial progenitors into digestive-enzyme secreting zymogenic cells requires Mist1.

Continuous regeneration of digestive enzyme (zymogen)-secreting chief cells is a normal aspect of stomach function that is disrupted in precancerous lesions (e.g. metaplasias, chronic atrophy). The cellular and genetic pathways that underlie zymogenic cell (ZC) differentiation are poorly understood. Here, we describe a gene expression analysis of laser capture microdissection purified gastric cell populations that identified the bHLH transcription factor Mist1 as a potential ZC regulatory factor. Our molecular and ultrastructural analysis of proliferation, migration and differentiation of the gastric unit in Mist1(-/-) and control mice supports a model whereby wild-type ZC progenitors arise as neck cells in the proliferative (isthmal) zone of the gastric unit and become transitional cells (TCs) with molecular and ultrastructural characteristics of both enzyme-secreting ZCs and mucus-secreting neck cells as they migrate to the neck-base zone interface. Thereafter, they rapidly differentiate into mature ZCs as they enter the base. By contrast, Mist1(-/-) neck cells differentiate normally, but ZCs in the mature, basal portion of the gastric unit uniformly exhibit multiple apical cytoplasmic structural abnormalities. This defect in terminal ZC differentiation is also associated with markedly increased abundance of TCs, especially in late-stage TCs that predominantly have features of immature ZCs. Thus, we present an in vivo system for analysis of ZC differentiation, present molecular evidence that ZCs differentiate from neck cell progenitors and identify Mist1 as the first gene with a role in this clinically important process.

Animals↗
PubMed1999

Fluid secretion by isolated Malpighian tubules of Drosophila melanogaster Meig.: effects of organic anions, quinacrine and a diuretic factor found in the secreted fluid.

Para-aminohippuric acid (PAH, 0.2 and 1 mmol l(-)(1)) had no effect on the basal fluid secretion rate (FSR) of isolated Malpighian tubules of Drosophila melanogaster Meig. and did not affect stimulation of the FSR induced by adenosine 3',5'-monophosphate (cAMP). Phenol Red (phenolsulphonphthalein, PSP; 0.5 and 1 mmol l(-)(1)) slowed the FSR and abolished stimulation of the FSR by cAMP. Diodrast (1 mmol l(-)(1)) slightly, but significantly, reduced the FSR and greatly reduced the stimulation of the FSR normally provoked by cAMP and by the 3',5'-monophosphates of guanosine (cGMP), inosine (cIMP) and uridine (cUMP). However, stimulation of the FSR by the 3', 5'-monophosphate of cytidine (cCMP) was little affected by diodrast. Probenecid (0.2 or 1 mmol l(-)(1)) consistently stimulated the FSR, on average by approximately 25 %, but did not markedly inhibit the subsequent stimulation of the FSR by cAMP, cGMP or cIMP. However, the FSR of tubules stimulated by cGMP was temporarily lowered by probenecid. Quinacrine (0.1 mmol l(-)(1)) slowed basal FSR by an average of approximately 30 %, but subsequent stimulation of the FSR by cAMP was not noticeably affected. Both 0.1 mmol l(-)(1) cAMP and 1 mmol l(-)(1) probenecid stimulated adenylate cyclase activity in extracts of Malpighian tubules, but cIMP, cGMP, cUMP and diodrast were without effect in this regard. Uptake of radioactivity from a solution containing 500 nmol l(-)(1) [(3)H]cAMP and 9.5 micromol l(-)(1) cAMP was reduced by more than 90 % by 1 mmol l(-)(1) PSP, by approximately 40 % by 0.2 mmol l(-)(1) probenecid, by 36 % by 1 mmol l(-)(1) diodrast and by 30 % by 1 mmol l(-)(1) PAH. Neither 0.01 mmol l(-)(1) ouabain nor 0.1 mmol l(-)(1) quinacrine affected the uptake of [(3)H]cAMP by the Malpighian tubules. Fluid secreted by isolated Malpighian tubules of Drosophila melanogaster contains a factor that stimulated the FSR on average by approximately 50 %. The presence in the secreted fluid of cGMP at a concentration of 8.3 micromol l(-)(1) did not explain the stimulatory effect on FSR. These results support the existence of a carrier-mediated uptake of cyclic nucleotides into the Malpighian tubules of Drosophila melanogaster, possibly involving a multispecific transporter.

Adenylyl Cyclases↗
PubMed2000

Twenty-kilodalton human growth hormone (20K hGH) secretion from growth hormone-secreting pituitary adenoma cells in vitro.

Circulating human growth hormone (GH) consists of several molecular isoforms. Increased proportion of circulating non-22K hGH and 20K hGH was reported in active acromegaly. In this study, we studied the release of 20K and 22K hGH from cultured GH-producing human pituitary adenoma cells in vitro. Pituitary adenoma cells obtained from 6 acromegalic patients were cultured and submitted to perifusion experiments. Concentrations of 20K and 22K hGH in the serum and the perifusion effluent were determined by specific enzyme-linked immunosorbent assays recently developed. The %20K value varied in a wide range from 3.58 to 8.72% in vitro and was lower than in the serum (mean+/-SD: 6.57+/-1.88% vs 9.08+/-2.12%, P<0.05). There was no correlation between the %20K values in vitro and in vivo (r=0.31, P>0.05). The in vitro secretions of 20K and 22K hGH were in parallel and strongly correlated (r=0.953, P<0.001). These findings suggest that different GH-producing pituitary adenoma cells secrete 20K hGH in variable amounts and that the proportion of 20K hGH in the serum might be affected by metabolic clearance of hGH isoforms. It was also suggested that 20K and 22K hGH might be secreted in toto from GH-producing human pituitary adenoma cells.

Acromegaly↗
PubMed2004

PPARgamma inhibits GH synthesis and secretion and increases apoptosis of pituitary GH-secreting adenomas.

OBJECTIVE: The objective of the study was to evaluate the expression and functional activity of Peroxisome proliferator-activated receptor (PPAR) gamma in pituitary adenomas from 14 consecutive acromegalic patients and to establish its role in apoptosis. SUBJECTS AND METHODS: Fourteen consecutive acromegalic patients were enrolled in the study. Wistar-Furth rats were used for in vivo studies. Expression of PPARgamma was evaluated by RT-PCR and Western blot. Apoptosis and cell cycle were assessed by FACS analysis. The effects of PPARgamma ligands on transcriptional regulation of GH gene were evaluated by RT-PCR and electromobility shift assay. RESULTS: PPARgamma was expressed in all human GH-secreting adenoma (GH-oma), in normal pituitary tissue samples (39+/-24% and 78+/-5% of immunostained nuclei respectively; P<0.0002; ANOVA), and in rat GH-secreting (GH3) cells. A PPRE-containing reporter plasmid transfected into GH3 cells was activated by ciglitazone or rosiglitazone (TZDs), indicating that PPARgamma was functionally active. Treatment of GH3 cells with TZDs increased apoptosis in a dose-dependent manner (P=0.0003) and arrested cell proliferation, reducing the number of cells in the S-phase (P<0.0001 vs untreated cells). TZDs increased the expression of TRAIL, leaving unaffected that of p53 and Bax. TZDs reduced GH concentrations in the culture media from 43.7+/-5.4 ng/ml to 2.1+/-0.3 ng/ml (P<0.0001) and in cell extracts (P<0.004). PPARgamma-RXRalpha heterodimers bound to GH promoter, inhibiting its activity and reducing GH mRNA levels (1.8 x 10(6) vs 5.7 x 10(6) transcripts respectively vs untreated cells; P<0.002). Subcutaneous GH-oma developed in rats injected with GH3 cells; tumor growth increased in placebo-treated rats and to a lesser extent in TZDs-treated animals (24.1+/-2.0 g, and 14.8+/-4.2 g respectively, P<0.03). Serum GH concentrations were lower in TZDs-treated rats than in controls (871+/-67 ng/ml vs 1.309+/-238 ng/ml; P<0.05). CONCLUSIONS: The results of this study indicate that PPARgamma controls GH transcription and secretion as well as apoptosis and growth of GH-oma; thus, TZDs have the potential of a useful tool in the complex therapeutic management of acromegalic patients.

Adenoma↗
PubMed1987

Influence of adrenergic receptors on ovarian progesterone secretion in the pseudopregnant cat and oestradiol secretion in the oestrous cat.

The infusion of isoprenaline or propranolol into the abdominal aorta of the pseudopregnant cat caused an increase or decrease respectively in the ovarian progesterone secretion rate. These observations suggest that the sympathetic innervation of the ovary has a physiological influence on normal progesterone secretion, and this mechanism may explain stress-related increases in progesterone concentrations. The infusion of isoprenaline or propranolol after the stimulation of follicular growth had no consistent or convincing effect on oestradiol secretion.

Animals↗
PubMed1993

Stimulation of rat placental lactogen-II (rPL-II) secretion by cultured trophoblasts by insulin: development of a rat placental cell culture system and effects of peptide hormones on rPL-II secretion in vitro.

The purpose of this study was to develop a primary culture system using serum-free medium for rat placental trophoblast cells and to investigate the factors that control rat placental lactogen-II (rPL-II) secretion in vitro. The placentae of day 13 pregnant rats were dissociated in Medium 199 containing 0.1% collagenase and 0.002% DNAase. Dissociated cells were fractionated into five segments by centrifugation through a 40% Percoll density gradient and incubated on rat tail collagen bed in medium SFM-101 for up to 7 days. Fraction B at the Percoll gradient density of 1.05 g ml-1 was enriched with rPL-II-producing cells and the time course of rPL-II secretion was characterized by a rapid increase in the first 2 days, remaining at high values (mean: 14-16 ng micrograms-1 DNA) for the following 2-3 days and decreasing thereafter. The rPL-II-producing cells from faction B identified by immunocytochemical examination accounted for approximately 69% of total cultured cells and consisted of a few giant cells and polygonal cells. Growth factors (bovine insulin, 0.1-20 micrograms ml-1; recombinant human insulin-like growth factor (IGF)-I, IGF-II, 0.1-1.0 micrograms ml-1; murine epidermal growth factor (EGF), 0.001-10 micrograms ml-1), rat pituitary hormones (rat growth hormone, rat prolactin, 0.1-10 micrograms ml-1) and hypothalamic hormones (human growth hormone-releasing hormone (GHRH), corticotrophin-releasing hormone (CRH), LHRH, 0.1-10 micrograms ml-1) were individually added to the culture medium to investigate the putative factors that directly control rPL-II secretion by the trophoblast cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2004

Serotonin antagonist-induced lowering of prolactin secretion does not affect the pattern of pulsatile secretion of follicle-stimulating hormone and luteinizing hormone in the bitch.

Dopamine agonists decrease plasma prolactin concentration and shorten the duration of anoestrus in the bitch. In order to determine whether this shortening results from decreased prolactin release or is due to another dopamine agonistic effect on the pulsatile release of FSH and LH, eight anoestrous beagle bitches were treated with a low dose of the serotonin antagonist metergoline (0.1 mg per kg body weight, twice daily) starting 100 days after ovulation. Six-hour plasma profiles of LH and FSH were obtained 7 days before, immediately before, 1 week after, and then at 2-week intervals after the start of the treatment with the serotonin antagonist until signs of pro-oestrus appeared. Plasma prolactin concentration was measured three times weekly from 75 to 142 days after ovulation and thereafter once weekly until the next ovulation, and was observed to decrease significantly after the start of treatment. The length of the interoestrous interval in the treated dogs was, however, not different from that in the preceding pretreatment cycle or from that in a group of untreated bitches. During the first weeks of treatment no changes were observed in the pulsatile plasma profiles of FSH and LH. Four weeks after the start of the treatment with the serotonin antagonist there was an increase in the mean basal plasma FSH concentration and the mean area under the curve for FSH, without a concurrent increase in LH secretion. The increase in FSH secretion continued until late anoestrus. In conclusion, the serotonin antagonist-induced lowering of plasma prolactin concentration was not associated with shortening of the interoestrous interval. The plasma profiles of LH and FSH were similar to those observed during physiological anoestrus, but different from those observed during anoestrus shortened by treatment with a dopamine agonist. Hence the prematurely induced oestrus observed during administration of dopamine agonists cannot be explained by a decreased plasma prolactin concentration but must be due to some other dopamine agonistic effect, probably increased FSH secretion. The observations in this study further strengthen the hypothesis that an increase in circulating FSH is essential for ovarian folliculogenesis and consequently the termination of anoestrus in the bitch.

Animals↗
PubMed2002

A critical reappraisal of MIB-1 labelling index significance in a large series of pituitary tumours: secreting versus non-secreting adenomas.

Pituitary tumours are usually benign neoplasia, but may have a locally aggressive or malignant evolution. This study aimed to identify factors which mostly influence their proliferative activity, in order to clarify its value for clinical and research purposes. The proliferative index was determined in a prospective series of 132 pituitary tumours as the percentage of monoclonal antibody MIB-1-immunopositive cells and referred to as the MIB-1 labelling index (LI). Its distribution was analysed according to both univariate and multivariate models. A life-threatening pituitary tumour is presented separately. The mean LI was 1.24+/-1.59%, with significant differences between clinically secreting (CS) and clinically non-secreting (CNS) adenomas. In CS adenomas (n=65), LI was highly variable and markedly influenced by pre-operative pharmacological treatment (0.80+/-1.03 vs 2.06+/-2.39% in treated vs untreated cases, P=0.009); it decreased with patient's age (P=0.025, r=0.28) and increased with tumour volume and invasiveness. The influence of pre-operative treatment and macroscopic features on LI in this group was confirmed by multivariate analysis. In CNS adenomas (n=67), LI distribution was less variable than in CS adenomas (P<0.0001), it was age-independent and correlations with tumour volume, invasiveness or recurrence did not reach significance. In a rapidly growing parasellar tumour, the mean LI was 24% at first surgery and exceeded 50% at second surgery performed 4 months later. LI should be interpreted according to hormone secretion and pre-operative treatment. Unusually high LI values deserve particular attention.

Adenoma↗
PubMed1979

Pancreatic exocrine secretion in the rat after chronic alcohol ingestion: nonparallel secretion of proteins and pancreatic secretory trypsin inhibitor.

Pancreatic secretion was studied in rats given 20% (v/v) ethanol or water ad libitum for 7--8 months. Basal secretion samples were collected for 30 min, after which secretion was stimulated with secretin (1.1 U/h) and cholecystokinin-pancreozymin (2.8 U/h). Then, four successive 30-min samples were collected. The flow rate, protein concentration and output, pancreatic secretory trypsin inhibitor (PSTI) concentration and output, and chymotrypsinogen concentration increased significantly from basal levels during the first stimulation period in both groups, with no significant differences between the groups. During the second, third, and fourth stimulation periods gradual decreases of these parameters were observed in both groups, and the decrease of volume, protein output, and PSTI output were significantly greater in the alcohol group than in the control group. No significant differences were observed in the concentrations of chymotrypsinogen, protein, and PSTI, but the PSTI/protein ratio was significantly lower in the alcohol group at the end of the experiment. The concentrations of bicarbonate did not decrease during stimulation and were elevated in the alcohol group compared with the control group during the fourth period. It is suggested that the decreased PSTI/enzyme ratio caused by long-term alcohol ingestion might favour premature activation of the proenzymes in the pancreatic ducts.

Alcoholism↗
PubMed1997

[A case of multiple endocrine neoplasia type I with primary hyperparathyroidism, prolactin secreting pituitary microadenoma and gastrin secreting duodenal carcinoid].

A case of MEN type I in a 64-year-old man is reported. He had undergone partial duodenectomy because of gastric ulcer and multiple duodenal polyps (gastrin secreting carcinoid). Blood examination revealed hypercalcemia, hyperPTHemia, and hyperprolactinemia. Neck US and CT showed enlargement of 4 parathyroid glands. Brain MRI revealed the microadenoma in left pituitary gland. Total parathyroidectomy with auto-transplantation in the left forearm were performed. Histological examination showed the hyperplasia of the parathyroid. Three and a half year after parathyroidectomy, there was no evidence of recurrence of gastrin secreting tumor and hyperparathyroidism, and enlargement of pituitary microadenoma. This is the first MEN type I case in Japan which have detected 3 endocrine tumors clinically with gastrin secreting duodenal carcinoid.

Adenoma↗
PubMed1975

[Effect of somatostatin on betazole-stimulated gastric secretion and carbachol-stimulated pancreatic secretion and gall bladder contraction in man(author's transl)].

The effect of somatostatin on betazole-stimulated gastric secretion and carbachol-stimulated pancreatic secretion and gall bladder contraction has been studied in seven healthy volunteers. Somatostatin (150 and 250 mug/h) inhibited dose-dependently volume of gastric juice and acid output stimulated by 16 mg betazole. Acid concentration was little affected. 500 mug/h were not more effective than 250 mug/h. Pancreatic secretion stimulated by 250 mug carbachol has been reduced by 80-90% and gall bladder contraction abolished by somatostatin infusion (200 mug/h).

Adult↗
PubMed2003

Time-dependent observations of secretion marker levels in nasal secretion after histamine and methacholine provocations.

Nasal provocation tests with histamine and methacholine were carried out on 25 healthy men in an effort to assess the dynamic changes of albumin, total IgA, secretory IgA and lactoferrin concentrations in the nasal secretion. The trials were performed with 0.5, 1, and 4 mg of histamine and 8, 16, and 32 mg of methacholine. Each dose of histamine or methacholine was sprayed into the nose every 2nd day, with two days' interval between the two provoking agents. Nasal secretions were collected after saline spraying only, forming the baseline group, after 3, 10 and 15 min of administration of the challenge agent. The baseline levels presented the following values: for albumin 257 +/- 230 microg/ml, secretory IgA 608 +/- 379 microg/ml, total IgA 1025 +/- 423 micog/ml, and lactoferrin 213 +/- 156 microg/ml. The increase in albumin level after nasal provocation, particularly significant after histamine administration (to 3713 +/- 2311 microg/ml), indicates incessant protein plasma leakage from the blood circulation to the nasal secretion. After administration of both provocating agents, there was a significant gradual decrease in secretory IgA level, even below the baseline value. After the 2nd and 3rd doses of methacholine and histamine spray, the concentration of secretory IgA decreased by 2-3 times and was found to be 200-300 microg/ml, respectively. Also, lactoferrin concentration values decreased gradually after the 2nd and 3rd doses of methacholine and histamine to levels close the baseline value. These observations suggest a time- and dose-dependent, non-specific dysfunction of local immunity response after nasal provocations.

Adult↗
PubMed2004

[Laparoscopic adrenalectomy in multiple endocrine tumors, in secreting and non-secreting lesions].

AIM: Personal experience in laparoscopic adrenalectomies (LA) for secreting and non-secreting tumors is presented. METHODS: Between March 1995 and December 2001 a total of 111 LA (58 left, 49 right and 4 bilateral) were performed in 60 females and 51 males, mean age 47.5 (range 8-81) years, for: 38 Conn diseases, 24 incidentalomas, 15 pheochromocytomas, 13 Cushing diseases, 4 kysts, 3 angiomyolipomas, 1 adreno-genital syndrome, 1 hydatidosis, 1 hyperplasia, 1 ganglioneuroma, 1 oncocyte adenoma, 1 adrenal fibrous tumor, 4 cortical carcinomas and 4 metastases (from renal carcinoma, breast carcinoma, leiomyosarcoma and rabdoid sarcoma, respectively). In all cases LA was transabdominal with a lateral flank approach. RESULTS: Mean global operative time was 88.6 minutes (range 35-240). Conversion rate was 1.8% (2/111). There was low postoperative pain. Mean hospital stay was 4.3 days (range 2-13). There were 0.9% (1/111) 30-day mortality and 4.5% (5/111) morbidity. During a mean follow-up of 41 months (range 1-81), the 67 secreting patients were disease-free. Concerning 8 malignant cases, mean follow-up was 40.5 months (range 9-72) with 3 cortical carcinomas disease-free and 1 dead for stroke, 2 metastases (1 leiomyosarcoma and 1 breast carcinoma) dead for disease and 2 disease-free. There was no port-site metastases. CONCLUSIONS: LA seems safe and effective when performed in experienced Centers on endocrine surgery and laparoscopy.

Adolescent↗
PubMed2005

[Drugs inhibiting parathyroid hormone (PTH) secretion by control of the calcium receptor (calcimimetics)--effect on the set point of calcium-regulated PTH secretion].

Calcimimetics are positive allosteric modulators that activate the parathyroid calcium receptor (CaR) and thereby immediately suppress parathyroid hormone (PTH) secretion. Preclinical studies have demonstrated that calcimimetics inhibit PTH secretion and parathyroid gland hyperplasia and ameliorates bone qualities in rats with chronic renal insufficiency. Clinical trials with cinacalcet hydrochloride, a calcimimetic compound, have shown that calcimimetics possess lowering effects not only on serum PTH levels but also on serum phosphorus levels in dialysis patients with secondary hyperparathyroidism (2HPT). Thus, calcimimetics have considerable potential as an innovative medical approach to manage 2HPT. In this review, the similarities are extrapolated between the pharmacological effect of calcimimetics on the set point of Ca-regulated PTH secretion and clinical observations in affected subjects with activating CaR mutations.

Animals↗
PubMed1992

[An experimental study of adrenalin-stimulated gastric acid secretion and gastrin secretion in rats of cysteamine-induced duodenal ulcer].

It is known that cysteamine-induced duodenal ulcers in rats are similar to the human duodenal ulcers in some aspects. We investigated their similarities in view of adrenalin-stimulated gastric acid secretion and gastrin secretion in these rats. Acid outputs decreased in the control group by the administration of adrenaline, but in the cysteamine-administered group acid outputs increased dose dependently. Serum gastrin levels and plasma noradrenaline levels increased by cysteamine administration. The abnormal gastric acid secretion by the adrenalin infusion in the process of cysteamine-induced duodenal ulcers in rats, which was resembled to that of duodenal ulcer patients, was recognized.

Animals↗
PubMedDate not supplied

[Secretion of periplasmic PhoA protein during its supersynthesis into the medium using outer membrane vesicles. Features of chemical composition of the vesicles and membranes of Escherichia coli secreting cells].

E. coli K12802 cells transformed by multicopy plasmid with phoA gene acquire the ability to oversynthesize alkaline phosphatase, secrete it into the cultural medium, and accumulate the precursor of this enzyme. The dynamics of enzyme production and secretion as well as cytomorphological changes revealed the existence of a mechanism of selective enzyme secretion into the medium. It is characterized by a decrease of enzyme specific activity in periplasm and its increase in cultural medium, appearance of numerous local zones of adhesion of cytoplasmic and outer membranes, formation of large extracellular outer membrane vesicles containing PhoA protein on the cell poles, and their release into the medium. We isolated the vesicles and found that they contain PhoA (in dominating quantity), several other periplasmic proteins, and matrix proteins of outer membranes. By their phospholipid and protein composition, they correspond to the fraction of outer membranes which have the largest density and sedimentation rate and, apparently, contain no lipoprotein.

Alkaline Phosphatase↗