Quantum chemical (MNDo)caleulations have beenused toelucidate the molecular properties and structure - activity relationships of dihydropyridine (DHP) type calcium antagonists. There is a good corielation between the net atomic charges on various atoms of the 4 - phenyl ring of dihydropyridines and pharmacological activity. .Also, activity decreases with increasing free rotation of the phen...

in this study, the influence of dopamine receptor agonists and antagonists on antinociception induced by bac10fen has been examined in the formalin test. the gaba-b agonist bac10fen induced antinociception in both phases of the formalin test in mice. the dopamine receptor agonists skf 38393 and quinpirole also induced antinociception in both phases of the test. skf 38393 but not quinpirole pote...

  In this study, we investigated the effect of nicotinic receptor agonists and antagonists on the analgesic response to morphine in the formalin test. In experiments conducted in mice, nicotine produced an early dose-dependent analgesic effect. At a dose of 0.5 mg/kg, mecamylamine, a nicotinic receptor inhibitor, suppressed the analgesic effect induced by 0.1 mg/kg nicotine in both stages of th...

Objective(s): Oxytocin is involved in modulation of many brain-mediated functions. In the present study, we investigated the central effects of oxytocin and its receptor antagonist, atosiban on inflammatory pain. The contribution of opiate receptors was explored using non-selective and selective antagonists. Materials and Methods: The fourth ventricle of the brain of anesthetized rats was impla...

Choroid plexus epithelial cells are enriched in mRNA for proteins such as the iron carrier transferrin, which acts as a trophic factor in the brain. Choroid plexus epithelial cells also have a high density of 5-HT1C receptors linked to activation of the phosphoinositide (PI) hydrolysis second messenger system. The present studies show that the 5-HT1C/5-HT2 receptor agonist 1-(2,5-dimethoxy-4-io...

1. Pressure-sensitive mechanosensory (P) neurones of the leech Hirudo medicinalis produce two responses to serotonin (5-HT): activation of a Cl- conductance and of a non-selective monovalent cation conductance. The effects of channel blockers, the receptor pharmacology and the second-messenger dependence of these responses were studied in voltage-clamped P cells in culture. Antagonists were app...

AIMS 5-Hydroxytryptamine (5-HT) is a potent vasoconstrictor and mitogen in the pulmonary vascular bed which exhibits phenotypical and functional heterogeneity according to size of the vessels. METHODS We thus investigated both contractile response and smooth muscle cell (SMC) proliferation in response to 5-HT in rat main extrapulmonary artery (MPA) and intrapulmonary arteries of the first and...

Losartan potassium, Valsartan , Telmisartan and Irbesartan are angiotensin-II-receptor antagonists (ARA II) group which used in treatment of hypertension alone or in combination with other drugs mainly Hydrochlorothiazide. RP- HPLC method was developed for the assay of three angiotensin-II-receptor antagonists (ARA-IIs) in presence of Hydrochlorothiazide. The method was performed by reversed ph...

The effect of NMDA (N-methyl-D-aspartate) receptor antagonists on tolerance to morphine antinociception was investigated in mice. Daily subcutaneous administration of 50 mg/kg of morphine hydrochloride for three days induced tolerance to different (3,6 and 9 mg/kg) test doses of morphine. The tolerance obtained was decreased by pretreatment of animals with single or repeated doses of compe...

PURPOSE A genetic polymorphism of the beta 2-adrenergic receptor is a major factor associated with the asthmatic phenotype. The association of this polymorphism with toluene diisocyanate (TDI)-induced asthma has not been investigated. We examined 103 TDI-induced asthma patients (TDI-OA), 60 asymptomatic exposed controls (AEC), and 263 unexposed healthy controls (NC) in order to identify beta 2-...