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)

Isolated rat neurohypophyses were fixed by their stalks to a platinum wire electrode and superfused with Krebs-HEPES solution. Vasopressin and oxytocin released into the medium were determined by specific radioimmunoassays. Hormone secretion was increased by electrical stimulation of the pituitary stalk at different frequencies. The effects of several potassium channel blockers, tetraethyl-ammonium (TEA) ions, 4-aminopyridine (4-AP) and 3,4-diaminopyridine (3,4-DAP) were tested. The release of vasopressin and oxytocin evoked by electrical stimulation with 900 pulses at 15 Hz (about 900 and 1,000 microU, respectively) was about 10 times higher than that evoked by 900 pulses at 3 Hz. Both 10 and 30 mmol/l TEA enhanced the release of vasopressin evoked by stimulation at 3 and 15 Hz, by 25- and 2-fold, respectively, to attain a maximum release of about 1,800 microU per stimulation. The stimulated release of oxytocin attained a maximum of about 9,000 microU at 15 Hz in the presence of 10 mmol/l TEA or at 3 Hz with 30 mmol/l TEA. Thus, in the presence of maximally effective concentrations of TEA both stimulation frequencies (3 and 15 Hz) were equieffective in evoking release of vasopressin and oxytocin. 4-AP or 3,4-DAP enhanced the release of vasopressin evoked by 15 Hz stimulation maximally to about 1,600 microU. In the presence of 4-AP or 3,4-DAP the release of oxytocin evoked by stimulation at 15 Hz increased maximally to about 8,000 microU and that evoked by stimulation at 3 Hz to about 1,500 microU.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differential effects of potassium channel blockers on neurohypophysial release of oxytocin and vasopressin. Evidence for frequency-dependent interaction with the endogenous opioid inhibition of oxytocin release. 285 13

The purpose of the present study was to compare the effect of seven drugs, that have been reported to enhance cognitive functions, on rat hippocampal cholinergic neuronal activity. The latter was assessed by measuring the effects of the drugs on in vitro sodium-dependent high affinity choline uptake (HACU) into rat hippocampal synaptosomes 30 minutes after their in vivo administration. 3,4-Diaminopyridine (0.1 mg/kg IP), like pramiracetam (44 and 88 mg/kg IP), increased HACU with higher or lower doses being ineffective. Centrophenoxine (100 mg/kg IP) decreased HACU. Piracetam (100 and 500 mg/kg IP), aniracetam (10-200 mg/kg PO), lysine vasopressin (0.005-0.05 mg/kg IM) and 4-aminopyridine (0.01-3.0 mg/kg IP) were ineffective. The results indicate that 3,4-diaminopyridine and centrophenoxine, like pramiracetam may be increasing cognitive function in part by affecting hippocampal cholinergic neuronal activity. In addition, the findings indicate the usefulness of using in vitro HACU as a biochemical measurement to assess the potential effect of cognitive-enhancing drugs on cholinergic neuronal activity in vivo.
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PMID:The effects of various cognition-enhancing drugs on in vitro rat hippocampal synaptosomal sodium dependent high affinity choline uptake. 298 37

The antianginal effects of palonidipine, a novel 1,4-dihydropyridine derivative, and nifedipine on various myocardial ischemic models were compared. (1) Palonidipine at 0.5 mg/kg, p.o. significantly inhibited vasopressin-induced ST depression of ECG in Donryu rats. This activity was about 5 times more potent than that of nifedipine and was long-lasting. (2) Palonidipine at 1 mg/kg, i.d. significantly inhibited ST depression induced by isoproterenol in Wistar rats. This activity of TC-81 was more potent than that of nifedipine. (3) Palonidipine at 3 micrograms/kg, i.v. produced an increase in regional myocardial tissue blood flow in the ischemic region of chronic coronary artery occluded dogs. (4) In isolated dog coronary artery, palonidipine at a concentration of 10(-10) M or greater inhibited the amplitude of 3,4-DAP-induced cyclic contractions in a concentration-dependent manner. This activity was 10-30 times more potent than that of nifedipine. (5) An intracoronary injection of endothelin (30 pmol/kg) reduced the coronary blood flow, subepicardial tissue blood flow, and subepicardial pH in anesthetized dogs. The ST elevation of ECG over 0.1 mV also occurred in 8 of 10 cases. In all the cases, ventricular extrasystoles were noted, and 9 out of 10 animals died. Pretreatment with palonidipine (3 micrograms/kg, i.v.) inhibited endothelin-induced ischemic changes, with a potency greater than that of nifedipine. These results suggest that palonidipine may be useful for the therapy of angina-pectoris.
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PMID:[Effect of palonidipine hydrochloride (TC-81), a new dihydropyridine derivative, on various myocardial ischemic models]. 837 May 58