Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Angiotensin-II (A-II) receptor subtypes and their potential coupling mechanisms were investigated in bovine adrenal fasciculata cells (BAC) in culture, by the use of selective antagonists for AT1 (DUP 753 or Losartan) and AT2 (PD 123177 and CGP 42112A) sites. Competition for [125I]A-II specific binding with AT1 or AT2 selective ligands produced a biphasic displacement curve, suggesting two distinct A-II binding sites. In the presence of PD 123177 (10(-5) M), a concentration at which most of the AT2 sites were saturated, DUP 753 displaced [125I]A-II specific binding in a monophasic manner with an IC50 of 6.2 +/- 1.4 x 10(-7) M. In the presence of DUP 753 (10(-5) M), the displacement produced by CGP 42112A and PD 123177 was also monophasic, with IC50s of 8 +/- 3 x 10(-10) and 4.6 +/- 2.1 x 10(-7) M, respectively. The reducing agent dithio-1,4-erythritol inhibited the binding of [125I]A-II to AT1 (DUP 753 sensitive) sites, but increased its binding to AT2 sites 2-fold. The IC50 values for these two effects were about 0.5 and 3 mM, respectively. The biological effects of A-II in BAC, phosphoinositide hydrolysis and cortisol production, were inhibited in a dose-dependent manner by DUP 753, but not by AT2 antagonists. Similarly, the potentiating action of A-II on corticotropin-induced cAMP production was blocked by DUP 753, but not by AT2 antagonists. These data indicate that BAC contain both receptor subtypes, but that all the known effects of A-II in BAC were induced via the AT1 receptor subtype.
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PMID:Characterization and coupling of angiotensin-II receptor subtypes in cultured bovine adrenal fasciculata cells. 132 66

In an attempt to determine the mechanism of pressor action of centrally administered rat joining peptide (rJP), a pro-opiomelanocortin (POMC)-derived peptide, we investigated its action on the angiotensin and adrenergic system in the brain stem. In conscious spontaneously hypertensive rats with chronic cannulas in the cisterna magna and abdominal aorta, the pressor effect of synthetic rJP in the cisterna magna was markedly inhibited by pretreatment with losartan, an antagonist of angiotensin (ANG) II receptor specific for its AT1 subtype, and also by the nonspecific antagonist [Sar1,Ile8]ANG II but not by AT2-specific PD-123319. Pretreatment with captopril did not alter the pressor response. Adrenergic receptor antagonists, yohimbine and propranolol, did not change the pressor response. The intracisternal joining peptide administration (10 and 30 nmol) increased the concentration of immunoreactive ANG II in cerebrospinal fluid 2.4- and 5.7-fold, respectively. These results indicate that the pressor response to rJP is mediated by the release of central ANG II and AT1 receptor. This study details a biological response to rJP, the only POMC-derived peptide whose action has not been identified previously.
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PMID:Angiotensin II-mediated pressor effect of rat joining peptide. 816 Aug 74

Differential evaluation of angiotensin II (Ang II) receptors (AT1A, AT1B and AT2) expression was performed in dispersed adenohypophyseal cells fractionated by unit gravity sedimentation. Binding of [125I-Sar1-Ile8]-Ang II and its displacement by specific nonpeptidic AT1 (DuP753) and AT2 (PD123319) antagonists was monitored throughout the gradient. Quantification of mRNA levels corresponding to both AT1 receptor subtypes (AT1A and AT1B) was achieved by reverse transcriptase polymerase chain reaction (RT-PCR) amplification in the presence of an AT1 receptor mutant cRNA as internal standard. Fractions were characterised by radioimmunoassay for the five major anterior pituitary hormones and by counting immunocytochemically labelled cells. Quantification of AT1 receptor subtype mRNA levels was also performed in four hypophyseal cell lines secreting prolactin, growth hormone, corticotropin and a gonadotropin subunit. As already described for the whole pituitary, AT1B receptor mRNA is predominantly expressed (80% of total AT1A + AT1B receptor mRNA content), whereas AT1A is expressed at lower level (20%) in dispersed pituitary cells. Most AT1 receptor mRNA and binding co-elute with fractions enriched in lactotropes and corticotropes. In contrast to AT1B, AT1A receptor mRNA is not present in heavier populations of lactotropes or in somatomammotropes. Low AT1B mRNA levels are detected in GH4C1 and in GC cells, two clones which secrete respectively prolactin and growth hormone. In contrast, no AT1 receptor mRNA expression was found in two other cell lines, AtT20 and alphaT3-1, which produce pro-opiomelanocortin and gonadotropin. It is concluded that expression of AT1 receptor subtypes is heterogeneous in different populations of lactotropes and corticotropes.
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PMID:Expression of angiotensin II receptor subtypes AT(1A) and AT(1B) in enriched fractions of dispersed rat pituitary cells. 943 Apr 47

Adrenocorticotropic hormone (ACTH; 5 microg/kg/ day) infused into 10 pregnant ewes (gestation age, 127-139 days) for 72 h caused an increase in arterial pressure within 1-2 h (p < 0.05), which was sustained for the rest of the experiment. Cardiac output was increased at 24 h (p < 0.05). Total peripheral resistance did not change. There were no changes in four pregnant ewes infused with 0.15 M saline at the same rate for 72 h. In ACTH-treated pregnant ewes, a relation between arterial pressure and plasma renin activity observed in nontreated pregnant ewes (r = 0.71; p = 0.0005) was no longer evident. Compared with nonsurgical pregnant ewes, total angiotensin II (Ang II)-receptor density in the uterine artery was decreased in ewes that had previously had surgery (p = 0.015) and further reduced in ACTH-treated ewes (p < 0.0005). This was due to a reduction in the AT2-receptor density, which was inversely related to plasma cortisol levels (r = 0.73; p < 0.03). AT1-receptor density and the affinities of the AT1 and AT2 receptors were unchanged. The correlation between plasma cortisol and AT2-receptor density in uterine blood vessels may partly explain why these receptors are downregulated after surgery.
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PMID:Effects of ACTH-induced hypertension in the pregnant ewe. 1059 25

Whereas collagen IV is expressed throughout the fetal adrenal gland during the second trimester of human development, fibronectin, and laminin demonstrate a rather mirror-image distribution, with higher expression of fibronectin in the central portion and laminin at the periphery of the gland. In the present study, extracellular matrices were able to modulate the profile of steroid secretion in primary cultures: collagen IV favored cortisol secretion following adrenocorticotropin (ACTH) or angiotensin II (Ang II) stimulation while specific stimulation of the AT2 receptor of Ang II elicited dehydroepiandrostenedione (DHEA) production. These effects were correlated by changes in mRNA levels of 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and cytochrome P450C17. In contrast, fibronectin and laminin decreased cell responsiveness to ACTH in terms of cortisol secretion, but enhanced ACTH-stimulated androgen secretion. Finally, extracellular matrices were able to orchestrate cell behavior: collagen IV and laminin enhanced cell proliferation whereas fibronectin incited cell death. These results indicate that the nature of extracellular matrix coordinates specific steroidogenic pathways and cell turnover in the developing human fetal adrenal gland.
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PMID:Fibronectin, laminin, and collagen IV interact with ACTH and angiotensin II to dictate specific cell behavior and secretion in human fetal adrenal cells in culture. 1253 Jun 75

The renin-angiotensin (ANG) system has been implicated in the development of hypertension in spontaneously hypertensive rats (SHR). Because SHR are more susceptible to stress than normotensive Wistar-Kyoto rats (WKY), we measured the mRNA expression of AT1A, AT1B, and AT2 receptors in the hypothalamo-pituitary-adrenal (stress) axis of male SHR in comparison to age-matched WKY at prehypertensive (3 to 4 weeks), developing (7 to 8 weeks), and established (12 to 13 weeks) stages of hypertension. AT1A receptor mRNA was mainly expressed in the hypothalamus and adrenal gland. AT1B receptor mRNA was detected in the pituitary and adrenal gland. AT2 receptor mRNA was prominent only in the adrenal gland. When compared with WKY, SHR showed increased AT1A receptor mRNA levels in the pituitary gland at all ages in contrast to reduced pituitary AT1B receptor mRNA levels. In the adrenal gland of SHR, AT1B receptor mRNA levels were decreased at the hypertensive stages when compared with WKY. The reduced expression of adrenal AT1B receptor mRNA was localized selectively in the zona glomerulosa by in situ hybridization. No differences were observed between WKY and SHR in the expression of hypothalamic ANG receptors. ANG significantly increased plasma levels of adrenocorticotropic hormone (ACTH) and corticosterone in dexamethasone-treated SHR but not in WKY. The aldosterone response to ANG was similar in SHR and WKY. Our results suggest a differential gene expression of AT1A and AT1B receptors in the hypothalamo-pituitary-adrenal axis of SHR and normotensive WKY and imply the participation of AT1 receptors in an exaggerated endocrine stress response of SHR to ANG.
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PMID:Differential expression of AT1 receptors in the pituitary and adrenal gland of SHR and WKY. 1289 May 82