To determine the specificity of the previously demonstrated competition of verapamil with radioligand binding to a-adrenergic receptors, we examined the interaction of calcium channel blockers with aiand a2-adrenergic receptors on several tissues. Verapamil competed for [H] prazosin binding to ai-adrenergic receptors and for [H]yohimbine binding to a2-adrenergic receptors in several tissues (hu...

Nifedipine (NIF) a 1, 4-dihydropyridine calcium channel antagonist, undergoes photodegradation to nitroso analogues of dehydronifedipine (NDNIF) when exposed to sunlight. Photodegradation products of NIF have no clinical activity, so different formulations of NIF must remain unchanged. If NIF preparations become unstable in exposure to light, they could cause therapeutic failure. The present st...

there is strong evidence demonstrating that nifedipine dissolved in ethanol selectively inhibits only l-type ca2+ current. in addition, acute ethanol exposure reduces voltage-dependent calcium currents. in the present study, we investigated the antagonistic effect of fixed concentration of nifedipine dissolved in different concentration of ethanol on l-type ca2+ current. in a na+-k+ free soluti...

Nifedipine (NIF), a 1,4-dihydropyridine calcium channel antagonist, undergoes photo-degradation to dehydro-nifedipine (DNIF) upon exposure to ultraviolet (UV) light and to the nitroso analogue of dehydro-nifedipine (NDNIF) when exposed to sunlight or some kinds of artificial lights. NIF photo-degradation products do not contribute to clinical activity, thus prevention of photo-degradation of NI...

Objective(s) This study aimed to investigate and to compare the effects of nifedipine and amlodipine, dihydropyridine (DHP) calcium channel blockers (CCBs) on perfusion pressure of isolated perfused rat kidney. Materials and Methods Following the establishment of renal perfusion with a constant baseline pressure of 85-95 mmHg, the renal vasculature was constricted by phenylephrine (PE) injec...

OBJECTIVES The purpose of this study was to assess the utility of inhaled nitric oxide (NO), a selective pulmonary vasodilator, for predicting the safety and acute hemodynamic response to high-dose oral nifedipine in primary pulmonary hypertension (PPH). BACKGROUND A significant decrease in pulmonary vascular resistance with an oral nifedipine challenge is predictive of an improved prognosis,...

-Our objective was to compare cardiovascular event rates in patients with stable angina receiving nifedipine as monotherapy or combination therapy and in active drug controls. A MEDLARS search of published articles from 1966 to 1995 in English, French, German, Italian, or Spanish, supplemented by a manual search of bibliographies, identified 60 randomized controlled trials that met protocol cri...

Background: Threatened preterm labor (TPL) is the leading cause of hospitalization during pregnancy. Tocolytic agents are the primary therapeutic options for TPL. The aim of this study is to compare intramuscular progesterone with oral nifedipine as a tocolytic agent. Methods: This randomized controlled trial was carried out in a teaching hospital (Shahid Akbarabadi) in Tehran, Iran, from De...