Drugs online research references
Eur J Pharmacol. 1983 Nov 25;95(3-4):239-45.
Effect of fenoterol on immunological release of leukotrienes and histamine from human lung in vitro: selective antagonism by beta-adrenoceptor antagonists.
Hughes JM, Seale JP, Temple DM.
The inhibitory effects of fenoterol, a beta 2-adrenoceptor agonist, on the release of SRS-A leukotrienes and histamine from chopped human lung tissue were measured and selective beta-adrenoceptor antagonists used to investigate the nature of the receptors involved. Fenoterol 0.01-1.0 microM inhibited the antigen-induced release of SRS-A and histamine, but not the release induced by the calcium ionophore A23187. Propranolol 0.1 and 1.0 microM and butoxamine 10 and 100 microM significantly antagonized the effects of fenoterol 0.1 microM on SRS-A and histamine at concentrations which affect (beta 2-adrenoceptors, while atenolol 0.1 to 10 microM showed no antagonism at concentrations which affect beta 1-adrenoceptors. These results suggest that adrenoceptors in human lung which modulate the immunological release of SRS-A leukotrienes are of the beta 2-subtype as for histamine release.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=6197312&dopt=Abstract
Regul Pept. 1991 Sep 3;35(3):207-19.
Bombesin-like immunoreactivity in skates and the in vitro effect of bombesin on coronary vessels from the longnose skate, Raja rhina.
Bjenning C, Farrell AP, Holmgren S.
Department of Zoophysiology, University of Goteborg, Sweden.
Bombesin-like immunoreactivity is present in nerve fibers projecting to the cardiovascular system, including the coronary arteries, and to the gastrointestinal canal, and in endocrine cells of the gut of skates belonging to the family Rajidae. Synthetic bombesin contracted isolated coronary rings from the longnose skate, Raja rhina, in a cumulative fashion. The contractile response was 84% of that of 60 mM potassium chloride. The pD2-value for bombesin was 8.83 (S.E.M. = 0.33; n = 15). Phentolamine, atropine and two substance P-antagonists increased the sensitivity to bombesin, while atenolol, sotalol, nifedipine, tetrodotoxin and two bombesin antagonists were devoid of significant effects. We conclude from this study that a bombesin-like peptide is present in nerves innervating the cardiovascular system and the gastrointestinal canal of skates of the family Rajidae, and that bombesin contracts coronary vessels in vitro via a direct mechanism and/or via mechanisms involving alpha-adrenergic and muscarinergic receptors.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1758976&dopt=Abstract
Basic Res Cardiol. 1990;85 Suppl 1:47-56.
Beta-adrenergic receptors and the Gs protein in myocardial ischemia and injury.
Maisel AS, Ransnas LA, Insel PA.
Department of Medicine, University of California, San Diego.
The purpose of this study was to explore alterations in the life cycle of adrenergic receptors and the Gs protein in the heart of ischemic animals. In initial experiments left anterior descending coronary artery occlusion was performed in guinea pigs. Sarcolemmal (SL) and light vesicle (LV) (presumably intracellular) fractions were prepared. Both fractions contained a substantial number of beta-adrenergic receptors and alpha 1-adrenergic receptors: the relative proportion of beta-adrenergic receptors in LV/SL was greater than for alpha 1-adrenergic receptors. Myocardial ischemia produced a rapid externalization of beta-adrenergic receptors from LV to SL. alpha 1-adrenergic receptors also increased in SL but without an apparent externalization from LV. Pretreatment of animals with either the non-selective beta-antagonist propranolol or the beta 1-selective antagonist atenolol increased the number of SL beta-receptors and blunted the ischemia-induced increase in SL beta-adrenergic receptors. Treatment with the partial agonist pindolol did not cause up-regulation of beta-receptors, and did not block ischemia-induced externalization. In the second part of this study, we have begun to examine post-receptor events in a rat model of myocardial ischemia. Ligation of the distal left main coronary artery in the rat led to an increase in SL beta-receptors. As G proteins play a pivotal role in transducing receptor occupancy to activation of effector molecules, we measured levels of Gs which stimulates adenylate cyclase activity, using an ELISA technique. In rat SL the amount of alpha s markedly decreased within 15 min of coronary occlusion. There was no transfer of Gs activity to the light vesicle fraction. These studies indicate the dynamic nature of adrenergic receptors and the alpha s protein in the sarcolemma in myocardial ischemia. Changes in adrenergic receptor number and in G protein expression may contribute to the altered pathophysiology of the ischemic heart.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1965404&dopt=Abstract
online pharmacies ||
Hair Million herbal formula for hair loss and hair growth ||
Amoxicillin ||
Tramadol ||
Paxil ||
Rx Drugs USA, Prescription Drugs Online Pharmacy ||
Zithromax ||
online pharmacy ||
Antibiotics and prescription medications online literature ||
Antibiotics