Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Guanine nucleotides and pertussis toxin were used to test for the involvement of a guanine nucleotide binding protein in the vasopressin V1 receptor-mediated stimulation of protein kinase C activity in Swiss 3T3 cells. Addition of vasopressin in the presence of [gamma-32P]ATP and digitonin caused a marked and rapid increase (8 +/- 1-fold after 1 min) in the phosphorylation of an Mr = 80,000 cellular protein (80K), a specific marker for protein kinase C activation. This phosphorylation was selectively blocked by the V1 receptor antagonist Pmp1-0-Me-Tyr2 [Arg8] vasopressin, indicating that the effect was mediated through the vasopressin V1 receptor. Down regulation of protein kinase C by prior prolonged pretreatment of intact cells with phorbol 12,13-dibutyrate (PBt2) blocked the ability of vasopressin to stimulate the phosphorylation of 80K in digitonin-permeabilized cells. Addition of a submaximal concentration of vasopressin together with the GTP analogue GTP-gamma-S caused a synergistic stimulation of 80K phosphorylation. The GDP analogue GDP-beta-S caused a 50% inhibition of the phosphorylation of 80K induced by a saturating concentration of vasopressin and shifted the vasopressin dose-response curve to the right. GDP-beta-S had no effect on the dose-response for the stimulation of 80K phosphorylation induced by PBt2. Prior incubation of intact quiescent cultures of Swiss 3T3 cells with pertussis toxin did not impair either vasopressin-induced increase in cytosolic [Ca2+] or activation of protein kinase C. These findings provide functional evidence for the involvement of a pertussis toxin-insesitive G protein in the vasopressin V1 receptor-mediated stimulation of protein kinase C in Swiss 3T3 cells.
 ...
PMID:Vasopressin rapidly stimulates protein kinase C in digitonin-permeabilized Swiss 3T3 cells: involvement of a pertussis toxin-insensitive guanine nucleotide binding protein. 253 Feb 40

In the present study we report the properties of vasopressin (VP) receptors in the anterior pituitary gland and show that the number of these receptors is markedly affected by adrenalectomy and hypothalamic lesions. VP-binding activity was assayed in particulate fractions of rat anterior pituitary glands using tritium-labeled arginine VP ([3H] AVP) as tracer. In the presence of Mg2+ the radioligand interacted with a single class of high affinity, low capacity binding sites. Magnesium ions modulated the affinity of the receptors but had no effect on binding capacity. Guanine nucleotides decreased the amount of tracer bound in a dose-dependent manner by increasing the dissociation constant (Kd) of the binding reaction by approximately 2-fold. Increasing the concentration of Mg2+ did not prevent this effect. Bilateral adrenalectomy (ADX) decreased pituitary AVP-binding activity: binding fell by 30% 4 h after surgery and declined further to 10% or less of control at 4 days. The decrease in binding was primarily due to a reduction in the number of receptors. Daily administration of corticosterone inhibited the reduction of binding activity at 4 days in a dose-dependent manner. Destruction of hypophyseotropic VP neurons by means of surgical lesioning of the hypothalamic paraventricular nucleus or the medial basal hypothalamus abolished the effect of ADX on pituitary AVP binding at 24 h but only attenuated the degree of receptor loss at 4 days. Furthermore, the lesions themselves caused a significant (approximately 30%) reduction in receptor number 4-7 days after hypothalamic surgery. Adrenalectomy reduced pituitary AVP-binding activity in homozygous (di/di) Brattleboro rats. The extent as well as the time course of the loss of receptor activity resembled that in normal rats. Rat anterior pituitary segments were exposed to synthetic CRF, AVP, or oxytocin (all 10(-7) M) for 4 h in vitro, and [3H] AVP-binding activity was subsequently determined. Both AVP and oxytocin reduced the amount of radioligand bound, while CRF had no effect. These observations allow the following conclusions: Magnesium ions and guanine nucleotides modulate the affinity of pituitary AVP receptors by different mechanisms and have no effect on binding capacity; Pituitary receptors for AVP are regulated by the amount of AVP released by paraventricular nucleus neurons as well as through a mechanism that requires the presence of corticosterone; Homozygous Brattleboro rats may respond to ADX by increased hypothalamic release of an endogenous ligand for pituitary AVP receptors.
 ...
PMID:Pituitary binding of vasopressin is altered by experimental manipulations of the hypothalamo-pituitary-adrenocortical axis in normal as well as homozygous (di/di) Brattleboro rats. 316 22

Forskolin is a unique diterpene that may directly activate the catalytic subunit of adenylate cyclase. We therefore examined the effect of 50 microM forskolin on osmotic water permeability in rabbit cortical collecting tubules perfused in vitro. Forskolin increased net volume flux (Jv, from 0.30 to 1.22 nl/mm/min, P less than 0.02) in all tubules. The hydro-osmotic effect of forskolin was similar with respect to magnitude and time course to that produced by a maximal dose (250 microU/ml) of arginine vasopressin. An additive effect on Jv and Lp was not observed when maximal concentrations of forskolin and arginine vasopressin were given simultaneously. The compound d(CH2)5Tyr(Et) VAVP, which noncompetitively inhibits the vasopressin receptor, significantly reduced collecting tubular hydro-osmotic response to arginine vasopressin. In contrast, the hydro-osmotic response to forskolin was maintained in the presence of d(CH2)5 Tyr(Et)VAVP. However, the hydro-osmotic response to forskolin could be inhibited by 1.0 microM guanine 5'-(beta,gamma-imido) triphosphate (GppNHp) and by the calmodulin inhibitor N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7). These results demonstrate that forskolin exerts an hydro-osmotic effect in the mammalian nephron which occurs independent of the vasopressin receptor. Guanine nucleotide regulatory proteins may modulate the osmotic water permeability effect of forskolin. Finally, calmodulin is required for full expression of the effect of forskolin to increase osmotic water flux.
 ...
PMID:Forskolin increases osmotic water permeability of rabbit cortical collecting tubule. 654 43

We studied the genetic basis of familial neurohypophyseal diabetes insipidus in a Japanese family. The members had polyuria and a deficiency of plasma vasopressin (AVP). Polymerase chain reaction (PCR) amplified exons of the AVP-neurophysin-II gene were subcloned and sequenced. Exons 1 and 3 were normal, but nucleotide 1884 Guanine (G) in exon 2 was substituted with Thymine (T), which induced a substitution of glycine (Gly) for valine (Val). To examine the presence of this mutation in the affected subjects, we designed two mutated primers. One of them induced a new endonuclease restriction site in the PCR fragments from normal, and the other induced a new endonuclease restriction site from patients with the mutation. DNA fragments from two affected members of this family were amplified with this primer, and the PCR products were digested by endonuclease and resolved by electrophoresis. The results indicated that these subjects had both normal and mutant alleles, indicating that the mutation was heterozygous. We concluded that this mutation caused neurohypophyseal diabetes insipidus in this family.
 ...
PMID:A new type of familial central diabetes insipidus caused by a single base substitution in the neurophysin II coding region of the vasopressin gene. 862 36