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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study examines the immediate and longer-term changes in angiotensinogen mRNA and in plasma angiotensinogen which follow the withdrawal and replacement of glucocorticoids or thyroxine. RNA from rat liver was analysed by Northern blot and dot-blot hybridization with a 40-mer oligodeoxynucleotide probe specific for angiotensinogen mRNA. Adrenalectomy decreased plasma angiotensinogen and angiotensinogen mRNA to 55 and 50% of control values respectively over a period of 16 days. Similar decreases were obtained after propylthiouracil (1 mg/kg for 16 days) treatment, except when injected simultaneously with T3 (3 micrograms/kg/day). Over the same period plasma renin activity increased in adrenalectomized rats from 4.1 +/- 0.8 to 7.0 +/- 1.5 pmol angiotensin I (AI)/ml/h, and decreased in propylthiouracil-treated rats from 3.8 +/- 0.4 to 1.6 +/- 0.4 pmol AI/ml/h. Approximate half-times of 2-3 days were calculated for both plasma angiotensinogen and angiotensinogen mRNA post-adrenalectomy or after propylthiouracil treatment. Dexamethasone (400 micrograms/kg, i.m.) given to intact rats rapidly increased angiotensinogen mRNA to a maximum of 250% of control by 8 h and with a half-maximal response of 2.8 h. Plasma angiotensinogen responded similarly, apart from an initial delay of 2 h. Treatment with different doses of propylthiouracil and dexamethasone showed that responses were dose-related. We conclude that changes in plasma angiotensinogen and angiotensinogen mRNA are closely correlated, and that under various physiological circumstances angiotensinogen mRNA has a rapid rate of accumulation but a slow rate of decay.
Mol Cell Endocrinol 1989 Feb
PMID:Regulation of liver angiotensinogen mRNA by glucocorticoids and thyroxine. 291 84

Autoradiographic techniques coupled with computerized microdensitometry and comparison with 125I standards were used to characterize and quantitate receptors for neuropeptides in rat brain and adrenal and pituitary glands. These techniques are rapidly performed, anatomically precise, and more sensitive than membrane binding techniques. They permit the determination of complete saturation curves and Scatchard analysis in discrete nuclei of the rat brain and in single rat pituitary and adrenal glands. Angiotensin II (AII) receptors were quantitated after incubation of 16-micron tissue sections with the AII agonist 125I-[Sar1]-AII. High-affinity, high-density AII receptors were present in the organon subfornicalis, organon vasculosum laminae terminalis and nuclei triangularis septalis, suprachiasmatis, and paraventricularis of the rat and in rat adrenal capsule-zona glomerulosa area, adrenal medulla, and anterior pituitary. These techniques could be used for precise localization and quantitation of other neuropeptide receptors in single rat brain nuclei, after optimizing the assay conditions and provided that suitable 125I ligands are available.
Cell Mol Neurobiol 1985 Sep
PMID:Quantitative autoradiographic characterization of receptors for angiotensin II and other neuropeptides in individual brain nuclei and peripheral tissues from single rats. 299 23

Islet-activating protein (IAP, a Bordetella pertussis toxin) was employed to test the hypothesis that the inhibitory GTP-binding regulatory protein of adenylate cyclase (Ni) mediates GTP effects on the binding of Ca2+-mobilizing hormones to liver plasma membranes and is involved in calcium mobilization stimulated by these agonists. IAP added to normal liver plasma membranes catalyzed the incorporation of radioactivity from [32P]NAD into a 41,000-Da peptide (presumably the alpha-subunit of Ni). However, no such incorporation was observed in liver membranes prepared from rats 24 hr after intraperitoneal injection of IAP. Angiotensin II attenuated glucagon-stimulated increases in cAMP in hepatocytes prepared from control but not IAP-treated rats. In contrast, following IAP treatment, no changes were observed in the ability of glucagon, vasopressin, angiotensin II, or epinephrine to activate phosphorylase; nor did this treatment alter [3H]vasopressin binding or epinephrine displacement of [3H]prazosin binding. However, IAP treatment decreased [3H]angiotensin II binding affinity when studies were performed in the absence but not the presence of 5'-guanylylimidodiphosphate (GppNHp). This shift was small and represented only 5-8% of the shift in apparent Kd elicited by GppNHp in untreated membranes. In vitro studies with IAP confirmed the results of the radioligand binding studies using in vivo IAP treatment. The effects of NaCl on [3H]angiotensin II binding were also tested but were not typical of other receptors which couple to Ni. The data suggest that, although a small population of hepatic angiotensin II receptors couple to Ni and attenuate glucagon-stimulated increases in cAMP, vasopressin, alpha 1-adrenergic, and the majority of angiotensin II receptors do not interact significantly with Ni. Thus, although there is evidence that agonist-induced Ca2+ mobilization requires a GTP-binding regulatory protein, this protein does not appear to be Ni in rat liver.
Mol Pharmacol 1986 Feb
PMID:Effect of islet-activating pertussis toxin on the binding characteristics of Ca2+-mobilizing hormones and on agonist activation of phosphorylase in hepatocytes. 300 28

The protein phosphorylation changes associated with the contraction and relaxation of bovine carotid artery smooth muscle were studied using two-dimensional gel electrophoresis of labeled phosphoproteins. Muscle was stimulated with histamine, angiotensin II, 12-deoxyphorbol 13-isobutyrate (DPB) or high extracellular K+. Histamine induced a rapid and sustained contraction which was associated with an early (2 min) phosphorylation of 20 kDa myosin light chain (MLC) and two cytosolic proteins, Nos. 1 and 2, and with the late (60 min) phosphorylation of MLC, two isoelectric variants of desmin and ten other cytosolic proteins. Additionally, there was a decrease in the extent of phosphorylation of two cytosolic proteins, Nos. 9 and 10. Angiotensin II induced a rapid but transient contraction which was associated with the same early (2 min) phosphorylation changes, but with none of the late (60 min) changes. Elevation of the extracellular K+ concentration to 110 mM led to a sustained contraction which was associated with the phosphorylation of MLC and proteins Nos. 1 and 2 at both 2 and 60 min, but none of the other late phase phosphoproteins were seen. Addition of DPB, an activator of protein kinase C, induced a slowly developing but sustained contractile response which was associated with none of the early (5 min) phosphorylation changes. However, nearly all of late (60 min) protein phosphorylation changes were the same as those seen after histamine action. Addition of forskolin to either control or histamine-treated muscle led to an increase in the phosphorylation of three cytosolic proteins (Nos. 3, 8 and 13), and in the histamine-contracted muscle the dephosphorylation of MLC and proteins Nos. 4, 9, 10, 15 and 16. Similarly, forskolin induced a relaxation of DPB-treated muscle and the dephosphorylation of proteins Nos. 4, 9, 10, 15 and 16. These results suggest that there are two pathways by which histamine activates contraction: a Ca2+-calmodulin pathway which initiates the response, and a protein kinase C pathway which, along with the Ca2+-calmodulin pathway, sustains contraction.
Mol Cell Endocrinol 1988 Nov
PMID:Protein phosphorylation changes in bovine carotid artery smooth muscle during contraction and relaxation. 321 89

The stimulation of phosphoinositide metabolism by angiotensin II (Ang II) was studied in [3H]inositol-labelled bovine adrenal glomerulosa cells. After separation of the phosphoinositols by ion-exchange high-performance liquid chromatography, it was shown that the formation of inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) and inositol 1,3,4-trisphosphate (Ins(1,3,4)P3) followed distinct kinetics. The first compound to increase upon stimulation with 10(-7) M Ang II was Ins(1,4,5)P3, which reached a maximum (250% of basal level) within 10 s. At lower concentrations of Ang II, this response was slower. The formation of Ins(1,4,5)P3 depended upon the concentration of Ang II, with an EC50 of 2.4 +/- 1.5 X 10(-9) M Ang II. The potency of Ang II in stimulating the turnover of phosphoinositides and in increasing the biosynthesis of aldosterone was very similar, whereas the peptide was ten times more potent in its ability to mobilize Ca2+. Ang II was also able to stimulate the production of Ins(1,4,5)P3 in permeabilized glomerulosa cells. This effect was mimicked by a non-hydrolysable analog of GTP (GTP gamma S), suggesting that a GTP binding protein is involved in the mechanism coupling the Ang II membrane receptor to phospholipase C. These results strengthen the view that Ins(1,4,5)P3 plays a key role as second messenger in the steroidogenic response to Ang II in adrenal glomerulosa cells.
Mol Cell Endocrinol 1988 Jun
PMID:Inositol trisphosphate isomers in angiotensin II-stimulated adrenal glomerulosa cells. 326 Dec 66

The aim of this study was to identify immunologically and biologically a renin-like enzyme (RLE) in rat corpora lutea (CL). The biological activity of partially purified extracts of CL was tested in vivo by injection into anesthetized pentolinium-treated rats, obtaining a pressor response similar to renal renin. The enzyme activity in vitro was inhibited to about 50% by pretreatment with a specific antibody against renal renin. When the extracts were incubated with angiotensinogen, the product was inhibited mainly by angiotensin I antibody. The fact that there was no change in RLE content in 24 or 48 h nephrectomized rats, suggested the idea of a local production rather than an active blood renin sequestration.
Mol Cell Endocrinol 1986 Oct
PMID:A renin-like enzyme in luteal tissue. 353 Aug 37

Angiotensin II can elicit cellular responses by 2 different receptor-dependent mechanisms: increase in intracellular calcium or inhibition of adenylate cyclase activity. The well-known inhibition of renin release from granulated cells of the kidney is thought to be mediated by an increase in intracellular calcium. However, the participation of the other possible pathway, i.e. inhibition of adenylate cyclase, has not been excluded. We studied this question by using the toxin from Bordetella pertussis, which inactivates the inhibitory coupling units Ni and thus permits to identify hormonal actions mediated through inhibition of adenylate cyclase. In isolated perfused kidneys from rats pretreated with pertussis toxin (2 micrograms/100 g i.v., single injection) the inhibition of renin release by angiotensin II (10(-11) to 10(-8) M) was significantly attenuated. In parallel, the vasoconstrictor response to angiotensin II was also diminished in these rat kidneys. The effect of pertussis toxin was apparent 3, 5 and 10 days after treatment, with a maximal effect at the fifth day. These data suggest that angiotensin II may exert the inhibitory effect on renin release in part through inhibition of adenylate cyclase in granulated cells of the kidney.
Mol Cell Endocrinol 1985 Sep
PMID:Pertussis toxin attenuates angiotensin II-induced vasoconstriction and inhibition of renin release. 393 13

Previous studies have documented that high affinity binding of [125I]angiotensin II to adrenal cortex receptors was modulated by guanine nucleotides. Since in other receptor systems, similar properties of hormone-receptor interactions were shown to be specific for agonists, we studied the differential binding characteristics of agonists and antagonists to this receptor using a new radiolabeled antagonist [125I] [Sar1,Ile8] angiotensin II. Receptor saturation studies indicate that the antagonist is binding to a homogeneous population of sites with a Kd of 0.6-2.0 nM and with a receptor density around 1 pmol/mg of protein. Competition curves using unlabeled antagonists are characterized by a slope factor of 1 and a single Kd of 1-3 nM. Addition of guanylylimidodiphosphate to the assay is absolutely without effect on radiolabeled antagonist binding. In contrast, competition curves using the full agonists angiotensin II, [Sar1]angiotensin II, angiotensin III, and [des-Arg]angiotensin III display slope factors of 0.79, 0.87, 0.70, and 0.84, respectively. These curves can be explained by two apparent forms of the receptor having high and low affinity for the agonist. The higher affinity form associated with these four agonists is characterized by a Kd of 1.2 nM, 0.25 nM, 0.8 nM, and 3 microM, and corresponds to 60, 56, 42, and 25% of angiotensin II-binding sites, respectively. The other form displays 13- to 33-fold lower affinity. Addition of guanine nucleotide to the assay results in a 2-4-fold shift to the right and a steepening (slope factor 0.9-1.0) of agonist competition curves. Angiotensin II receptors, occupied by the full agonist [131I] [Sar1] angiotensin II or by the antagonist [125I] [Sar1, Ile8]angiotensin II, were then solubilized with the nonionic detergent octylglucoside. Dissociation of the agonist [131I] [Sar1] angiotensin II from solubilized receptors is enhanced by guanylylimidodiphosphate or sodium acetate, while dissociation of the antagonist [125I] [Sar1, Ile8]angiotensin II displays little sensitivity towards guanine nucleotides or increased ionic strength. Inclusion of bile salts in the solubilization medium preferentially destabilizes receptor-bound agonist, presumably by interfering with protein-protein interactions required for high affinity agonist binding. Separation of radiolabeled agonist and antagonist-occupied solubilized receptor complexes by steric exclusion high performance liquid chromatography reveals that the agonist-occupied receptor complex behaves as a larger protein than the antagonist-occupied receptor complex.(ABSTRACT TRUNCATED AT 400 WORDS)
Mol Pharmacol 1984 Nov
PMID:Evidence for agonist-induced interaction of angiotensin receptor with a guanine nucleotide-binding protein in bovine adrenal zona glomerulosa. 609 99

Hepatic plasma membranes of female obese mice C57 BL-6 orl ob/ob (ob/ob mice) completely lack vasopressin (VP) receptors of the V1 type whereas kidney VP receptors are normally expressed and functionally coupled to adenylate cyclase. To discover if these alterations are linked to a genetic defect of the V1 receptor, we have studied the binding of VP on liver and kidney membranes of two other models, female diabetic mice C57 BL-6 orl db/db (db/db mice) and female Zucker rats Fatty/orl fa/fa (fa/fa rats), which exhibit different temporal pattern of obesity, hyperinsulinemia and insulin resistance. In addition, since VP is known to exert its vascular response through stimulation of V1 receptors, we have studied the reactivity of VP of isolated tail artery in the three different models, ob/ob and db/db mice and fa/fa rats, and in their respective controls. In all cases, VP kidney receptors and VP vascular reactivity are normal. db/db mice exhibit a marked decrease in hepatic VP receptors whereas a 50% decrease was observed in 32 week fa/fa rats. Angiotensin II and prazosin binding sites are still present as well as the adenylate cyclase response to glucagon. These results suggest that the specific alteration in liver VP receptors is not related to a defect in V1 receptor genetic expression but is specific for liver and appears to parallel the level of hyperinsulinemia and/or insulin resistance.
Mol Cell Endocrinol 1984 Dec
PMID:Reduction in hepatic but not in renal and vascular vasopressin receptor number in hyperinsulinemic mice and rats. 609 84

The hydrolysis of substance P is catalyzed by purified rabbit lung angiotensin-converting enzyme (peptidyldipeptide hydrolase, EC 3.4.15.1). The kcat/Km for the reaction at 37 degrees is 3.3 +/- 0.3 X 10(3) M-1 sec-1, which is 60 times less than that which has been reported for the hydrolysis of angiotensin I. The initial site of hydrolysis is the antipenultimate peptide bond, which generates the tripeptide amide (Gly-Leu-Met-NH2). This hydrolysis is inhibited by the angiotensin-converting enzyme inhibitors captopril, MK-422, and EDTA, and is dependent on the concentration of chloride ion. Both captopril and MK-422 potentiate the substance P-induced stimulation of salivation in rats. Thus, angiotensin-converting enzyme may be one of the enzymes that degrade substance P in vivo.
Mol Pharmacol 1984 Mar
PMID:Carboxyl-terminal tripeptidyl hydrolysis of substance P by purified rabbit lung angiotensin-converting enzyme and the potentiation of substance P activity in vivo by captopril and MK-422. 619 59


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