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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The production of prostaglandins by rat renal tubular cells and by rat vascular smooth muscle cells (VSMC) in response to vasoactive hormones was examined. A superfusion technique was used to stimulate collagenase-dispersed renal cortical or medullary tubular cells and trypsinized rat aortic smooth muscle cells with vasoactive hormones and ANF. All cell types responded promptly to the stimuli in a dose-dependent manner. Renal tubular cells produced mainly PGE2, less PGF2 alpha and no 6-keto-PGF1 alpha, while VSMC produced exclusively 6-keto-PGF1 alpha. This production of PG was strictly dependent on the presence of extracellular Ca2+ and was not inhibited by antagonists of voltage-dependent Ca2+-channels. Angiotensin II (Ang II) was active on cortical tubular cells and VSMC. Sar1-Ala8-angiotensin II blocked this action. Arginine-vasopressin (AVP acted on medullary tubular cells and VSMC and its effect was inhibited by selective V1-antagonists. The V2-agonist dDAVP had no effect on PG production. A clear distinction between V1-receptor mediated PG release and V2-receptor mediated cAMP extrusion was observed in medullary tubular cells. Bradykinin was a weak agonist on medullary tubular cell. The synthetic (1-24) atrial natriuretic peptide did not prevent 6-keto-PGF1 alpha release induced by Ang II or AVP in VSMC nor the PGE2 release in cortical tubular cells induced by Ang II.
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PMID:The regulation of prostaglandins by vasoactive hormones in renal tubular and vascular smooth muscle cells. 312 55

Rat renal papillary collecting duct (PCD) cells were isolated using collagenase and hyaluronidase digestion and a three-step low-speed centrifugation. As assessed by binding of the lectin Dolichos biflorus and determination of vasopressin-sensitive adenylate cyclase and Na+-K+-ATPase, the enrichment of PCD cells over a crude papillary cell preparation was 1.8, 2.4, and 1.4, respectively. Microscopic evaluation indicated that the preparation was greater than 90% pure PCD cells. The isolated cells were viable as evident from the high K/Na ratio of intracellular electrolytes measured by electron probe analysis (5.3), from the high ATP/ADP ratio (2.15), and the metabolic response to alterations in Na transport. Exposure to 2 mM ouabain or removal of Na reduced O2 consumption by 25-35%; the uncoupler carboxylcyanide-m-chlorophenylhydrazone more than doubled O2 consumption. In the presence of 14 mM glucose and at a PO2 of 100 Torr the cells produced substantial quantities of lactate. This aerobic glycolysis may account for greater than 20% of the ATP production. In the presence of rotenone, glycolysis increased by 56% and was able to maintain the cellular ATP level at 65% of control. In the absence of any exogenous substrate PCD cells respired normally and had a close to normal ATP content, but lactate production was markedly decreased. These results demonstrate that viable PCD cells can be isolated from rat kidney. At normal PO2 and in the presence of D-glucose the cells show a substantial amount of aerobic glycolysis, although their mitochondrial respiration is not rate limiting. In the absence of glucose the cells derive the majority of their energy from an as yet unidentified endogenous substrate.
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PMID:Purification of rat papillary collecting duct cells: functional and metabolic assessment. 330 74

The epithelial cells of the toad bladder have been isolated by brief exposure to ethylenediaminetetraacetic acid followed by treatment with collagenase, DNAse, and the application of shearing forces. This approach eliminates the need for scraping of the mucosal surface and reduces mechanical damage during harvesting of the epithelium. The method yields intact, isolated epithelial cells and few clumps. The three major types of epithelial cells described in the intact toad bladder were present in the final preparation. The cellular contents of nucleic acids and proteins (in pg/cell) were: DNA 22.5 +/- 1.1; RNA, 12.9 +/- 0.6; and protein, 192 +/- 9. The isolated cells possess rates of oxygen consumption and amino acid incorporation higher than those of epithelial sheets obtained by collagenase treatment and scraping of the intact bladder. However, the production of cyclic nucleotides in response to stimulation by vasopressin and carbachol is comparable in both preparations.
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PMID:Isolation of epithelial cells from toad bladder. 624 42

Hormone-dependent adenylate cyclase activity was measured separately in the different nephron portions by combining the microdissection of collagenase-treated rabbit kidneys and the use of a single tubule enzyme microassay. The results obtained in the rabbit for vasopressin, parathyroid hormone, calcitonin, and isoproterenol are given and discussed. Each hormone stimulated adenylate cyclase activity in several well-localized segments of tubule according to a highly specific and reproducible pattern. Sharp transitions were generally noted between responsive and unresponsive nephron portions. In the rat kidney, the functional segmentation of the distal convoluted tubule was not as clearly delineated as in the rabbit kidney. Various nephron segments of the rat kidney were observed to contain glucagon-sensitive adenylate cyclase activity. When the results obtained for vasopressin are compared in rabbit, rat, mouse, and human kidneys, species differences are noted with respect to the responsiveness to arginine vasopressin in the medullary portion of thick ascending limbs of Henle's loops. It is concluded that biochemical approaches can be used as a means of investigating problems dealing with kidney physiology very near the cell level.
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PMID:Sites of hormone action in the mammalian nephron. 625 51

Previous studies have shown that vasopressin stimulates the mitotic activity in adrenal zona glomerulosa cells in intact as well as in hypophysectomized rats. (Payet and Isler, Cell and Tissue Res. 172, 1976; Payet and Lehoux, J. steroid Biochem. 12, 1980). We now report that this effect is direct and specific, since vasopressin stimulates the mitotic activity of rat adrenal zona glomerulosa cells in primary cultures. These cells were prepared by dissociation with collagenase in the culture medium MEM-d-Valine. Isolated cells were placed in 3.5 diameter petri dishes in MEM-d-valine medium containing 15% fetal calf serum and antibiotics for two days and 5% fetal calf serum for subsequent cultures. The medium was changed at 24 hr intervals. The hormones were added 3 days after the culture was started. The mitogenic effect of vasopressin was found to be dependent both on time and hormone concentrations. Vasopressin (10(-11) M) stimulated thymidine incorporation 4.8 +/- 0.6-fold after 2 days of treatment and 5.3 +/- 1.6-fold after 8 days. When ACTH (10(-11) M) was added together with vasopressin (10(-11) M) the mitogenic effect was enhanced at 6.5 +/- 1.9-fold after 2 days and 12.9 +/- 6.9-fold after 8 days of treatment. The aldosterone and corticosterone outputs were also stimulated by the combined presence of vasopressin and ACTH in the incubation medium; a maximal effect was observed between 6 and 8 days of treatment. Vasopressin (10(-11) M) + ACTH (10(-11) M) stimulated the aldosterone output 7-fold and that of corticosterone by 18-fold. When added alone, vasopressin, as well as ACTH alone had only a small effect on the aldosterone output. However, ACTH alone stimulated the corticosterone output 10-fold. In conclusion, vasopressin is an important and specific growth factor of the adrenal zona glomerulosa cells. In addition, together with ACTH vasopressin stimulates the aldosterone and corticosterone output both in vivo and in vitro in primary cell cultures.
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PMID:Vasopressin: a potent growth factor in adrenal glomerulosa cells in culture. 632 70

Several angiogenic preparations that have been shown to stimulate plasminogen activator (PA) and collagenase production by cultured bovine capillary endothelial (BCE) cells were tested for their ability to stimulate BCE cell motility in the phagokinetic track assay. Bovine retinal extract, medium conditioned by 3T3-F442A differentiated mouse adipocytes, SK HEP-1 human hepatoma cell lysate, mouse sarcoma 180 cell lysate, and medium conditioned by mouse sarcoma 180 cells stimulated motility 68.7%, 48.5%, 140.9%, 56.5%, and 102.1%, respectively, relative to untreated cells. The motility-stimulating activity of these preparations was dose dependent and linear over the 16-h assay period. Several hormones and growth factors were tested for BCE cell motility-stimulating activity, including insulin, vasopressin, fibroblast growth factor, and a partially purified preparation of sarcoma growth factor, and were found to be ineffective. 12-0-tetradecanoyl-phorbol-acetate (TPA), a potent stimulator of both PA and collagenase activities in BCE cells, also did not stimulate motility, indicating that protease production is not sufficient to stimulate BCE cell motility in this assay. Neither SK HEP-1 hepatoma cell lysate nor TPA was effective in stimulating motility in bovine aortic endothelial (BAE) cells. The inability of SK HEP-1 hepatoma cell lysate to stimulate movement in BAE cells is consistent with the observation that angiogenesis occurs by sprouting of capillaries, not large vessels.
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PMID:Stimulation of motility in cultured bovine capillary endothelial cells by angiogenic preparations. 632 76

We examined effects of osmolality or sodium concentration on vasopressin induced cyclic AMP generation in the medullary thick ascending limbs isolated from collagenase treated rat kidneys. Vasopressin-stimulated cyclic AMP generation was increased as a function of NaCl concentration of the incubation medium. Addition of sucrose was also effective in enhancing the vasopressin-stimulated cyclic AMP, whereas addition of urea was without effect. When incubation medium was made hypertonic with sodium cyclamate, vasopressin-stimulated cyclic AMP generation was also enhanced. When choline chloride was used instead of sodium cyclamate, only an insignificant increase in the hormone-stimulated cyclic AMP generation was observed. These results suggest that the responsiveness of the rat medullary thick ascending limbs to vasopressin is regulated, at least in part, by transmembrane osmotic gradient.
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PMID:Effects of solute concentration on vasopressin stimulated cyclic AMP generation in the rat medullary thick ascending limbs of Henle's loop. 632 7

The effects of alterations in extracellular calcium concentration on prostaglandin (PGE) and thromboxane (TXB2) syntheses were studied in isolated epithelial cells from the urinary bladder of the toad, Bufo marinus. In epithelial cells prepared using collagenase, basal iPGE synthesis was greater than iTXB2 synthesis. Increasing extracellular calcium from zero to 1 mM increased iPGE synthesis and decreased iTXB2 synthesis equivalently such that total conversion of endogenous arachidonate to these two metabolites was unaltered. Vasopressin stimulated iPGE and iTXB2 syntheses when the incubation buffer contained 1 mM calcium but had no effect in the presence of 0.4 microM calcium. In contrast, using an EDTA isolation method, basal iPGE and iTXB2 syntheses were equal in the presence of zero calcium. Increasing extracellular calcium concentration to 1 mM caused a greater enhancement in iTXB2 synthesis compared to iPGE. Increasing extracellular calcium to 2 mM was associated with a decline in iPGE and iTXB2 syntheses back to the levels observed with no calcium added to the medium. The effect of increasing the calcium concentration was greater in phosphate than in bicarbonate buffer. In a Tris buffer the effect of altered calcium was almost completely abrogated. These studies demonstrate that the choice of buffer and alterations in extracellular calcium concentration differentially alter basal arachidonic acid metabolism to prostaglandins and thromboxane in isolated toad urinary bladder cells. The results suggest that there may exist several endogenous pools of arachidonic acid which are differentially influenced by calcium. Furthermore, the pool sensitive to vasopressin has an absolute requirement for calcium.
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PMID:Alterations in extracellular calcium concentration differentially influence prostaglandin and thromboxane synthesis in epithelial cells from the toad urinary bladder. 642 55

Sites of action of vasopressin along the nephron were investigated by using a microassay for adenylate cyclase for single pieces of tubule microdissected from collagenase-treated kidneys. In the rabbit, not only the medullary and cortical portions of collecting tubules, but also the thin and thick segments of the ascending limb of Henle's loop were observed to contain adenylate cyclase highly responsive to arginine-vasopressin. In contrast, the other segments of the nephron-including the descending limb of the loop, the distal convolution, and the connecting tubule -- were unresponsive to vasopressin. Qualitative and quantitative species difference were noted between rabbit, rat, mouse and man, regarding vasopressin responsiveness in distal tubules and ascending limbs. As an example, adenylate cyclase in thick ascending limb is not sensitive to vasopressin in man whereas, in rat, it is as responsive as the collecting tubule. The physiological relevance of these results is discussed.
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PMID:[Vasopressin action sites along the nephron (author's transl)]. 727 40

The relationship between vasopressin (VP) receptor levels in the anterior pituitary and VP-stimulated ACTH release in vitro was studied in rats subjected to various chronic stress paradigms. The stress models used were water deprivation for 60 h and administration of 2% NaCl in the drinking water (both of which are associated with decreased pituitary ACTH responsiveness), and repeated i.p. hypertonic saline injections or repeated daily immobilization for 14 days (associated with increased ACTH responsiveness to novel stimuli). VP receptors were measured by binding of [3H]arginine-VP to anterior pituitary membrane-rich fractions, and ACTH responses to VP in collagenase dispersed anterior pituitary cells. In control rats, binding of [3H]AVP was saturable and high affinity, with a Kd of 0.45 +/- 0.05 nM and a Bmax of 138.8 +/- 8.1 fmol/mg. In pituitary membranes from stressed rats, binding affinity was unchanged, but Bmax changed according to the type of stress. While VP binding was markedly reduced after water deprivation and 2% saline (25% and 49%, respectively), it was significantly increased after repeated i.p. hypertonic saline injections and repeated immobilization (126% and 154% of controls, respectively). The changes in VP binding were associated to parallel changes in maximum VP-stimulated ACTH production in vitro, with a 34% decrease in water deprived rats and a 25% increase in hypertonic saline injected rats. The potentiating effect of VP on corticotropin releasing hormone-stimulated ACTH was also reduced in cells from water-restricted rats, and increased in cells from rats given repeated injections of hypertonic saline. The data show a direct relationship between changes in corticotroph responsiveness and changes in pituitary VP receptors during chronic stress, suggesting that pituitary VP receptor regulation is involved in the adaptation of the HPA axis during chronic stress.
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PMID:Regulation of pituitary vasopressin receptors during chronic stress: relationship to corticotroph responsiveness. 761 75


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