Vasopressin-binding sites in the pig pituitary gland: competition by novel vasopressin antagonists suggests the existence of an unusual receptor subtype in the anterior lobe

1994 ◽  
Vol 141 (3) ◽  
pp. 383-391 ◽  
Author(s):  
Y Arsenijevic ◽  
M Dubois-Dauphin ◽  
E Tribollet ◽  
M Manning ◽  
W H Sawyer ◽  
...  
Keyword(s):  
Pituitary Gland ◽  
Rat Liver ◽  
Arginine Vasopressin ◽  
Binding Sites ◽  
Anterior Lobe ◽  
Receptor Subtype ◽  
Lower Affinity ◽  
Corticotrophin Releasing Factor ◽  
Rat Pituitary ◽  
Acth Release

Abstract Arginine vasopressin (AVP) acts in the pituitary gland, in synergy with corticotrophin-releasing factor, to induce ACTH release in response to stressful stimuli. Pituitary AVP receptors in the rat are coupled to phospholipase C, as are the so-called V1-type AVP receptors. The present study examined [3H]AVP binding in membranes prepared from the anterior lobe of the pituitary gland of the pig. [3H]AVP, alone or in competition with analogues, bound to sites in the pig anterior lobe which are pharmacologically similar to those described previously by others in the rat pituitary gland. For comparison, the same competition studies were performed on membrane preparations from the rat liver which contain the classic V1-type AVP receptor. Pituitary and liver AVP-binding sites were dissimilar; both cyclic and linear V1 antagonists had, in general, a much lower affinity for pituitary AVP-binding sites than for those in the liver. Thus, Phaa-d-Tyr(Et)-Phe-Gln-Asn-Lys-Pro-Arg-NH2 (Phaa=phenylacetyl) has a 2500-fold greater affinity for the latter (negative logarithm of inhibition constant (pKi)=9·64) than for the former (pKi=6·22). One linear antagonist, Pa-d-Tyr-Phe-Val-Asn-Arg-Pro-Arg-Arg-NH2 (Pa=propionyl) had about equal affinities for liver and pituitary membranes (pKi=6·39 and 6·53 respectively). Another compound, Phaa-d-Tyr-Phe-Val-Asn-Arg-Pro-Arg-Arg-NH2 had the highest affinity found to date for binding to AVP sites in the pituitary (pKi=7·43). These findings suggest some ideas for the design of more potent and/or selective AVP analogues acting in the pituitary gland. Journal of Endocrinology (1994) 141, 383–391

In-vitro effects of corticosterone, synthetic ovine corticotrophin releasing factor and arginine vasopressin on the release of adrenocorticotrophin by fetal rat pituitary glands

1984 ◽  
Vol 101 (3) ◽  
pp. 339-344 ◽  
Author(s):  
J. P. Dupouy ◽  
A. Chatelain
Keyword(s):  
Arginine Vasopressin ◽  
Fetal Life ◽  
Spontaneous Release ◽  
Sharp Rise ◽  
Corticotrophin Releasing Factor ◽  
Fetal Rat ◽  
Rat Pituitary ◽  
Pituitary Glands ◽  
Acth Release

ABSTRACT The in-vitro release of ACTH by fetal rat pituitary glands on days 17, 19 and 21 of pregnancy was measured using radioimmunoassay. The spontaneous release of ACTH, expressed in pg ACTH/gland per h, increased with fetal age, in correlation with the sharp rise in pituitary ACTH content. However, since pituitary ACTH content was nearly sevenfold higher at term than on day 17, while basal release of ACTH was only threefold higher, one can speculate that the spontaneous release of ACTH was proportionally greater on day 17 than on day 21 of gestation. As corticosterone, at a physiological concentration (865 nmol/l), reduced ACTH release, it was concluded that the pituitary gland was one site of the negative feedback action of the corticosteroids during fetal life. Quantities of synthetic ovine corticotrophin releasing factor (CRF) which gave concentrations of 0·3–30 nmol/l in the incubation medium induced a sharp rise in ACTH release which was log-dose dependent between 0·3 and 3 nmolCRF/1 on day 17 and between 0·3 and 30 nmolCRF/1 on days 19 and 21. The response to CRF increased with fetal age. Quantities of arginine vasopressin (AVP) which gave concentrations of 2–200 nmol/l stimulated ACTH release at all stages of gestation investigated. However, the response to AVP was much lower than that to CRF. Potentiation of CRF-induced ACTH release was not observed when whole pituitary glands from 21-day-old fetuses were incubated with AVP (20 nmol/l) + CRF (3 nmol/l). Such results were correlated with the ontogenesis of immunoreactive vasopressin- and CRF-containing fibres in the median eminence of the rat fetus, as well as with the CRF-like immunoreactivity present in adult rat pituitary portal plasma and the AVP content of the fetal rat hypophysis. J. Endocr. (1984) 101, 339–344

Arginine-Vasopressin Stimulates CRH and ACTH Release by Rat Adrenal Medulla, Acting Via the V 1 Receptor Subtype and a Protein Kinase C-Dependent Pathway

Peptides ◽  
1997 ◽  
Vol 18 (2) ◽  
pp. 191-195 ◽  
Author(s):  
Giuseppina Mazzocchi ◽  
Ludwik K Malendowicz ◽  
Pierra Rebuffat ◽  
Cinzia Tortorella ◽  
Gastone G Nussdorfer
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Adrenal Medulla ◽  
Arginine Vasopressin ◽  
Receptor Subtype ◽  
Kinase C ◽  
Dependent Pathway ◽  
Acth Release

scholarly journals Immunocytochemical demonstration of tissue-type plasminogen activator in endocrine cells of the rat pituitary gland.

1985 ◽  
Vol 101 (1) ◽  
pp. 305-311 ◽  
Author(s):  
P Kristensen ◽  
L S Nielsen ◽  
J Grøndahl-Hansen ◽  
P B Andresen ◽  
L I Larsson ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
Endocrine Cells ◽  
Large Population ◽  
Cell Types ◽  
Anterior Lobe ◽  
Tissue Type ◽  
Intermediate Lobe ◽  
Posterior Lobe ◽  
Rat Pituitary

We immunocytochemically stained rat pituitary glands using antibodies against plasminogen activators of the tissue type (t-PA) and the urokinase type (u-PA). A large population of endocrine cells in the anterior lobe of the gland displayed intense cytoplasmic immunoreactivity with anti-t-PA. In some areas of the intermediate lobe we found a weak staining, and we observed weakly staining granular structures in the posterior lobe. Controls included absorption of the antibodies with highly purified t-PA. In addition, SDS PAGE followed by immunoblotting of pituitary gland extracts revealed only one band with an electrophoretic mobility similar to that of t-PA when stained with anti-t-PA IgG. No u-PA immunoreactivity was detected in the rat pituitary gland. Sequential staining experiments using antibodies against growth hormone and t-PA demonstrated that the t-PA-immunoreactive cells constitute a large subpopulation of the growth hormone-containing cells. These findings represent the first direct evidence for the presence of t-PA in cell types other than endothelial cells in the intact normal organism. In this article we discuss the implications of the results for a possible role of t-PA in the posttranslational processing of prohormones.

Dexamethasone inhibits ovine corticotrophin-releasing factor (oCRF), arginine vasopressin (AVP), and oCRF + AVP stimulated release of ACTH during the last third of pregnancy in the sheep fetus

1987 ◽  
Vol 65 (6) ◽  
pp. 1186-1192 ◽  
Author(s):  
Laurie J. Norman ◽  
John R. G. Challis
Keyword(s):  
Negative Feedback ◽  
Arginine Vasopressin ◽  
Late Pregnancy ◽  
Feedback Effect ◽  
Plasma Acth ◽  
Fetal Sheep ◽  
Corticotrophin Releasing Factor ◽  
Basal Release ◽  
Sheep Fetus ◽  
Acth Release

We examined the hypothesis that in fetal sheep during late pregnancy exogenous glucocorticoids might affect differentially the pituitary response, measured as changes in plasma ACTH concentrations, to the systemic administration of ovine corticotrophin-releasing factor (oCRF), arginine vasopressin (AVP), or oCRF + AVP. At d 113–116 of pregnancy, equimolar injections of oCRF and AVP given separately provoked similar significant increases in plasma ACTH; the change in ACTH over basal values was significantly greater than the sum of the two separate responses when AVP + oCRF were given together. Exogenous dexamethasone did not affect basal ACTH concentrations, but suppressed significantly the responses to oCRF, AVP, and oCRF + AVP. At d 126–130, there was a significant ACTH response to CRF alone and to AVP + oCRF, but not to AVP alone. The response during the first 30 min postinjection to oCRF was significantly less than that to AVP + oCRF. Plasma Cortisol rose after each peptide injection. Exogenous dexamethasone suppressed both basal and stimulated responses to each peptide. At the amounts injected, there was no significant ACTH or Cortisol response to oCRF, AVP, or oCRF + AVP at d 136–140, but dexamethasone suppressed basal ACTH and Cortisol concentrations at this time. We conclude that stimulated, but not basal, release of ACTH is subject to the negative feedback effect of exogenous glucocorticoid by d 113–116 of gestation in fetal sheep. Both basal and stimulated release of ACTH and Cortisol are suppressed after d 125. At the amount of exogenous dexamethasone given, oCRF, AVP, and oCRF + AVP-stimulated responses are affected similarly. Our results suggest different controls of basal and stimulated ACTH release from the pituitary at d 113–116 of gestation. Our findings would be consistent with the pituitary as a level of action for the negative feedback effect of corticosteroids on stimulated ACTH release throughout the last third of pregnancy in fetal sheep.

GROWTH IN MONOLAYER CULTURE OF RAT PITUITARY CELLS WHICH SYNTHETIZE AND RELEASE ACTH

1975 ◽  
Vol 79 (3) ◽  
pp. 421-430 ◽  
Author(s):  
R. E. Lang ◽  
I. Hilwig ◽  
K. H. Voigt ◽  
H. L. Fehm ◽  
E. F. Pfeiffer
Keyword(s):  
Pituitary Gland ◽  
Monolayer Culture ◽  
Pituitary Cells ◽  
Dependent Manner ◽  
Antibody Technique ◽  
Gland Cells ◽  
Rat Pituitary ◽  
Rat Pituitary Cells ◽  
Dose Dependent ◽  
Acth Release

ABSTRACT Cultures of rat pituitary gland cells were developed to study biosynthesis and release of ACTH. ACTH measurement was accomplished by radioimmunoassay. ACTH release was observed following stimulation with theophylline and cAMP in a dose-dependent manner. Biosynthesis was demonstrated by incorporation of 3H-phenylalanine into the hormone, employing a double antibody technique.

Role for serotonin3 receptors in the control of adrenocorticotropic hormone release from rat pituitary cell cultures

1995 ◽  
Vol 133 (2) ◽  
pp. 251-254 ◽  
Author(s):  
Aldo E Calogero ◽  
Gyorgy Bagdy ◽  
Nunziatina Burrello ◽  
Pietro Polosa ◽  
Rosario D'Agata
Keyword(s):  
Pituitary Gland ◽  
Receptor Antagonist ◽  
Cell Cultures ◽  
Adrenocorticotropic Hormone ◽  
Pituitary Cell ◽  
Hormone Release ◽  
Mdl 72222 ◽  
Rat Pituitary ◽  
Ics 205 930 ◽  
Acth Release

Calogero AE, Bagdy G, Burrello N, Polosa P. D'Agata R. Role for serotonin3 receptors in the control of adrenocorticotropic hormone release from rat pituitary cell cultures. Eur J Endocrinol 1995;133:251–4. ISSN 0804–4643 Although several serotonin (5-HT) receptor types have been shown capable of stimulating the release of adrenocorticotropic hormone (ACTH) from the pituitary gland, relatively little is known about the role of the 5-HT3 receptor, a receptor that has generated a great deal of interest for its involvement in many behavioral and therapeutic effects. Hence, in this study, we tested the effects of the 5-HT¾ receptor antagonist 3-tropanyl-indole-3-carboxylate (ICS 205-930) and the selective 5-HT3 receptor antagonist 3-tropanyl-3,5-dichlorobenzoate (MDL 72222) on ACTH release stimulated by 5-HT from primary cultures of rat pituitary cells. Subsequently, we evaluated the effects of the selective 5-HT3 receptor agonist 1-(m-chlorophenyl)-biguanide (m-CPBG) on basal, corticotropin-releasing hormone (CRH)- and arginine vasopressin (AVP)-stimulated ACTH release. The maximal stimulatory effect of 5-HT (10−9 mol/l on ACTH release was antagonized by both ICS 205-930 and MDL 72222, suggesting that 5-HT stimulates basal ACTH release through activation of 5-HT3 receptors. Accordingly, m-CPBG stimulated basal ACTH release in a concentration-dependent fashion. In contrast to 5-HT, m-CPBG did not have any effect on CRH-stimulated ACTH release and inhibited AVP-stimulated ACTH release in a concentration-dependent manner. These data suggest that the 5-HT3 receptor is involved in the release of ACTH from the pituitary gland in vitro. Aldo E Calogero, Istituto di Clinica Medica I, Ospedale Garibaldi, Piazza S Maria di Gesú, 95123 Catania, Italy

Effects of TRH, prolactin and TSH on cell proliferation in the intermediate lobe of the rat pituitary gland

1996 ◽  
Vol 148 (2) ◽  
pp. 193-196 ◽  
Author(s):  
T Pawełczyk ◽  
M Pawlikowski ◽  
J Kunert-Radek
Keyword(s):  
Cell Proliferation ◽  
Body Weight ◽  
Pituitary Gland ◽  
Anterior Lobe ◽  
Intermediate Lobe ◽  
Proliferating Cells ◽  
Rat Pituitary ◽  
Trh Analogues ◽  
Intermediate Pituitary Lobe ◽  
Significant Stimulatory Effect

Abstract The effect of TRH on cell proliferation in the anterior lobe of the pituitary is well known and documented. On the other hand, there are no data on the effects of TRH on the intermediate lobe of the pituitary gland. The aim of this study was to investigate the effect of TRH and its analogues (pGlu-His-Gly, pGlu-His-Gly-NH2) on cell proliferation in the intermediate pituitary lobe. The bromodeoxyuridine technique was used to detect the proliferating cells. It was found that TRH stimulated cell proliferation 24 h after a single injection at a dose of 100 μg/kg body weight. The TRH analogues did not exert any significant stimulatory effect either 12 h or 24 h after the injection. The second experiment was carried out to distinguish the probable mechanism of the action of TRH. The effects of TSH and prolactin (PRL) on intermediate lobe cell proliferation were examined. It was found that both PRL and TSH exerted a significant stimulatory effect 24 h after a single s.c. injection of PRL at a dose of 150 IU/kg body weight or TSH at a dose 20 IU/kg body weight. It therefore appears that the stimulatory effect of TRH on intermediate pituitary lobe cell proliferation is mediated by PRL and TSH. Journal of Endocrinology (1996) 148, 193–196

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