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)

Intra-abdominal sepsis was induced in rats by implanting into their abdominal cavities fecal-agar pellets impregnated with Escherichia coli and Bacteroides fragilis. Sham-operated rats received sterile pellets. A group of sterile- and septic-implanted rats was treated intraperitoneally with diltiazem (1.2 mg/kg) 8 h after implantations. Septic- and sterile-implanted rat hepatocytes were loaded with 1) the fluorescent dye indo-1 to quantify hepatocyte basal and vasopressin (100 nM)-elevated cytosolic Ca2+ concentration and 2) 45Ca to quantify Ca2+ flux and cellular content of exchangeable Ca2+. Lipid peroxidation was determined by measuring conjugated dienes (CD) and thiobarbiturate-reactive substances (TBA-RS) in liver homogenates. In septic-implanted rats, the basal cytosolic [Ca2+], cellular exchangeable Ca2+, Ca2+ flux, CD, and TBA-RS were significantly higher than in sterile-implanted rats. Although vasopressin caused a significant elevation in cytosolic [Ca2+] in septic rat hepatocytes, the magnitude of this elevation was significantly smaller than that found in the sterile group. Diltiazem treatment of septic rats significantly decreased basal cytosolic [Ca2+], cellular exchangeable Ca2+ content, Ca2+ flux, CD, and TBA-RS. Also, vasopressin-induced increase in hepatocyte cytosolic [Ca2+] in diltiazem-treated septic rats was significantly greater than that observed in untreated septic rats. Both Ca2+ and membrane lipid alterations were attenuated with diltiazem treatment of septic rats. These results suggest that prevention or attenuation of Ca2+ channel-mediated Ca2+ influx restores both Ca2+ homeostasis and membrane lipid alteration.
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PMID:Ca(2+)-related hepatocellular alterations during intra-abdominal sepsis. 141 41

The modulatory effect of Ca on [Arg8]vasopressin-dependent (AVP) cAMP metabolism was studied in medullary collecting tubules (MCT) and medullary ascending limbs (MAL) microdissected from rat kidney. In MCT segments incubated in vitro with AVP, the accumulation of cAMP was enhanced (delta +59%) when Ca was omitted from the incubation medium compared with a medium with 2 mM of ionized calcium (Ca2+). Ionophore A23187 caused a decrease in AVP-stimulated cAMP accumulation in MCT in the presence of 2 mM Ca2+ but not in a Ca2+-free medium. Diltiazem and verapamil enhanced the AVP-stimulated cAMP accumulation in MCT; PTH had no detectable effect. A23187 caused a dose-dependent inhibition of cAMP accumulation stimulated by AVP with forskolin in both MCT and in MAL. However, in MAL the A23187 concentration needed for half-maximum inhibition (6.3 X 10(-6) M) was higher than for MCT (3.9 X 10(-7) M). The maximum inhibition in MAL (-65%) was less than in MCT (-97%). In the presence of 3-isobutyl-1-methylxanthine, AVP-stimulated cAMP accumulation was inhibited by A23187 in MCT (-45%) but not in MAL. Naproxen or ibuprofen did not relieve the inhibitory action of A23187 in MCT. Added Ca2+ inhibited the AVP-stimulated adenylate cyclase in MCT and MAL (half-maximum approximately equal to 5 X 10(-4) M Ca2+) and stimulated cAMP phosphodiesterase (cAMP-PDIE) in both MCT and in MAL (half-maximum approximately equal to 9 X 10(-5) M Ca2+). Incubation of MCT and MAL with A23187 decreased (-50%) the content of ATP. Results suggest that increased influx of extracellular Ca2+ inhibits the AVP-stimulated cAMP accumulation in MCT and to a much lesser degree in MAL. Deceased cAMP accumulation in MCT is probably due to both stimulation of cAMP-PDIE and the inhibition of adenylate cyclase, whereas in MAL it is due to stimulation of cAMP-PDIE. The results suggest that Ca2+ influx exhibits a negative modulatory effect on AVP-dependent cAMP metabolism mainly in MCT.
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PMID:Effects of calcium on the vasopressin-sensitive cAMP metabolism in medullary tubules. 241 23

The effect of diltiazem on vasoconstrictor responses was investigated in the feline mesenteric vascular bed under conditions of controlled blood flow. Diltiazem inhibited vasoconstrictor responses to sympathetic nerve stimulation, tyramine and norepinephrine suggesting that responses to both nerve-released and exogenous norepinephrine are dependent in part on an extracellular source of calcium. The calcium entry antagonist inhibited vasoconstrictor responses to alpha 1 and to alpha 2 adrenoceptor agonists over a wide range of concentration. Diltiazem also inhibited mesenteric vasoconstrictor responses to angiotensin II, vasopressin, prostaglandin F2 alpha and KCl. The inhibitor effects of diltiazem on vasoconstrictor responses to nerve stimulation and the pressor agents were reversible, and all responses returned to control value 30 to 45 min after the infusion of the calcium entry antagonist. The present data suggest that the inhibitory effects of diltiazem on responses to sympathetic nerve stimulation are postjunctional in nature, as responses to nerve-released and exogenous norepinephrine and nonadrenergic pressor agents are reduced to a similar extent. The present results suggest that vasoconstrictor responses to neuronally released and exogenous norepinephrine, as well as agents which activate membrane receptors or depolarize vascular smooth muscle in the feline mesenteric vascular bed, are dependent in part on an extracellular source of calcium. The inhibitory effects of diltiazem on vasoconstrictor responses to sympathetic nerve stimulation and pressor hormones may be relevant to the antihypertensive actions of this calcium entry antagonist.
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PMID:Inhibitory effects of diltiazem on vasoconstrictor responses in the cat. 289 47

1. The aim of the present study was to determine whether antianginal efficacy of semotiadil fumarate (SD-3211), a structurally novel calcium antagonist, is distinct from those of diltiazem, nifedipine and nisoldipine. 2. First, the duration of the inhibitory effects of semotiadil was compared with that of other Ca2+ antagonists in rat experimental angina evoked by vasopressin. Semotiadil (10 mg kg-1, p.o.) was effective for at least 9 h in the anginal model and those effects of semotiadil were longer-lasting than those of diltiazem (30 mg kg-1, p.o.), nifedipine (10 mg kg-1, p.o.), and nisoldipine (3 mg.kg-1, p.o.). 3. Second, the selectivity of actions of these Ca2+ antagonists for the coronary arteries and myocardium was evaluated in rat isolated perfused hearts. Diltiazem (10(-6) M) reduced cardiac contractility without inhibiting the elevation of perfusion pressure evoked by acetylcholine. Semotiadil (10(-7) M) significantly suppressed cardiac contractility and inhibited the coronary response to acetylcholine. In contrast, nifedipine (3 x 10(-9)-3 x 10(-8) M) and nisoldipine (3 x 10(-10)-10(-8) M) did not reduce cardiac contractility at concentrations which significantly inhibited the increase in perfusion pressure to acetylcholine. 4. The selectivity of semotiadil for coronary artery and myocardium is intermediate between diltiazem and dihydropyridines tested in the present study. 5. These findings suggest that semotiadil has an advantage of diltiazem, nifedipine, and nisoldipine in the treatment of angina with regard to long-lasting action and selectivity for coronary artery and myocardium.
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PMID:Pharmacological profile of semotiadil fumarate, a novel calcium antagonist, in rat experimental angina model. 856 35