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

We examined the effect of platelet-activating factor (PAF) on renal vascular reactivity in the pentobarbital sodium-anesthetized male Wistar rat. Intrarenal infusion of C16-PAF at hypotensive (2.5 ng.min-1.kg-1) or nonhypotensive (0.5 ng.min-1.kg-1) doses caused renal vasodilation and dose dependently antagonized the renal vasoconstrictor responses of intrarenal boluses of angiotensin II (ANG II) greater than norepinephrine (NE) greater than vasopressin (AVP). PAF infusion at the high dose did not alter non-receptor-mediated renal vasoconstriction induced by intrarenal KCl injection. The inhibitory effect of PAF on agonist-induced renal vasoconstriction was accentuated by eicosanoid synthesis inhibition (indomethacin or dexamethasone), unaffected by dopamine-receptor blockade (haloperidol) but was totally abolished by PAF receptor antagonism (L-659,989). In contrast, intrarenal infusion of a calcium channel antagonist (nimodipine) or an intracellular calcium channel antagonist (TMB-8) equally inhibited the renal vasoconstrictor responses of ANG II, NE, and AVP. Thus PAF can cause renal vasodilation in the rat kidney and dose-dependently antagonizes the renal vasoconstrictor responses of ANG II greater than NE greater than AVP. The inhibitory effect of PAF on renal vasoconstrictor responses is mediated by PAF receptors and does not appear to be due to a nonspecific membrane effect, reduction in calcium mobilization, or the release of vasodilatory eicosanoids or dopamine.
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PMID:Selective inhibition of vasoconstrictor responses by platelet-activating factor in rat kidney. 190 4

The effects of two classes of phospholipids (PL) on renal function have been studied. Bolus injections of 1 ng (10 pmol) of lysophosphatidylcholine (LPC) caused natriuresis and diuresis in rats. Natriuretic activity was eliminated by substituting unsaturated bonds in the 1-acyl group and by removing the choline group on the sn-3 position. Natriuretic activity was not affected by substitution of 1-alkyl for 1-acyl groups. In the dog, LPC was natriuretic when given as a bolus of 3.0 micrograms/kg or as a constant infusion at 5 ng/kg/min. To explore further the effect of alkyl PLs on renal function, a series of studies with platelet activating factor (PAF) was performed. PAF injected directly into the renal artery (IR) in bolus doses of 0.5-10 ng/kg caused renal vasodilation that was blocked by a specific PAF receptor antagonist. This effect was not due to release of vasodilatory eicosanoids, dopamine, or nitric oxide (NO). PAF given IR as a continuous infusion at 2.5 ng/kg/min attenuated the renal vasoconstrictor effects of angiotensin II and norepinephrine but not vasopressin. This effect to attenuate vasoconstriction was blocked by the NO inhibitor N-monomethyl-L-arginine. These studies using picomolar amounts of PL suggest a physiologic role for these compounds in control of renal function.
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PMID:Effects of phospholipids on renal function. 750 37

We investigated the presence of PAF receptor subtypes in the tissues of the gastrointestinal tract, airways, blood vessels and in murine macrophages. For this purpose we have used a competitive PAF receptor antagonist, yangambin (YAN), extracted from the Brazilian plant "louro de cheiro" (Ocotea duckei Vattimo). Rat duodenum, jejunum, ileum, colon, stomach fundus, trachea and bronchia were removed and 1.5-2 cm muscle segments from those regions were mounted in a 10 ml organ bath with aerated physiological solution at 37 degrees C. PAF evoked a contraction of the rat jejunum, ileum, colon and stomach fundus. The contraction was slow and resistant to wash and was followed by desensitization to further doses of PAF. Contractions induced by PAF (10(-6) M) were inhibited by YAN (10(-7) to M-2 x 10(-5) M) and WEB 2086 (10(-6) m to M-5 M) in rat jejunum, ileum and colon but not in the stomach fundus. In the rat stomach fundus only WEB 2086 (5 x 10(-6) M) was able to block PAF-induced contraction. The contractions induced by acetylcholine, histamine, 5-hydroxytryptamine and vasopressin were not inhibited by prior administration of YAN. Yangambin also significantly inhibited PAF-induced vascular permeability in rat duodenum, jejunum, ileum, colon, and mesentery. Yangambin significantly inhibited PAF-induced lipid body formation in mice peritoneal macrophages. We suggest that YAN is a selective PAF antagonist which is able to discriminate putative PAF receptors subtypes present in the stomach fundus.
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PMID:Yangambin, a lignan obtained from Ocotea duckei, differentiates putative PAF receptor subtypes in the gastrointestinal tract of rats. 1082 Oct 44