Drugs online research references
J Pharmacol Exp Ther. 1999 Feb;288(2):814-9.
Improving effects of huperzine A on spatial working memory in aged monkeys and young adult monkeys with experimental cognitive impairment.
Ye JW, Cai JX, Wang LM, Tang XC.
State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, P.R. China.
Our previous studies demonstrated that huperzine A, a reversible and selective acetylcholinesterase inhibitor, exerts beneficial effects on memory deficits in various rodent models of amnesia. To extend the antiamnesic action of huperzine A to nonhuman primates, huperzine A was evaluated for its ability to reverse the deficits in spatial memory produced by scopolamine in young adult monkeys or those that are naturally occurring in aged monkeys using a delayed-response task. Scopolamine, a muscarinic receptor antagonist, dose dependently impaired performance with the highest dose (0.03 mg/kg, i.m.) producing a significant reduction in choice accuracy in young adult monkeys. The delayed performance changed from an average of 26.8/30 trials correct on saline control to an average of 20.2/30 trials correct after scopolamine administration. Huperzine A (0.01-0. 1 mg/kg, i.m.) significantly reversed deficits induced by scopolamine in young adult monkeys on a delayed-response task; performance after an optimal dose (0.1 mg/kg) averaged 25.0/30 correct. In four aged monkeys, huperzine A (0.001-0.01 mg/kg, i.m.) significantly increased choice accuracy from 20.5/30 on saline control to 25.2/30 at the optimal dose (0.001 mg/kg for two monkeys and 0.01 mg/kg for the other two monkeys). The beneficial effects of huperzine A on delayed-response performance were long lasting; monkeys remained improved for about 24 h after a single injection of huperzine A. This study extended the findings that huperzine A improves the mnemonic performance requiring working memory in monkeys, and suggests that huperzine A may be a promising agent for clinical therapy of cognitive impairments in patients with Alzheimer's disease.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9918593&dopt=Abstract
J Pharm Biomed Anal. 1998 Dec;18(4-5):815-25.
Capillary electrophoresis for the analysis of tropane alkaloids: pharmaceutical and phytochemical applications.
Mateus L, Cherkaoui S, Christen P, Veuthey JL.
Laboratory of Pharmaceutical Analytical Chemistry, University of Geneva, Switzerland.
Three capillary electrophoresis methods, using UV detection, were developed for the simultaneous determination of several tropane alkaloids, including atropine, scopolamine and synthetic derivatives. After optimization, the validated capillary zone electrophoresis methods were applied to the determination of these compounds in various pharmaceutical forms, such as ophthalmic and injection solutions, tablets, suppositories and aerosols. Capillary electrophoresis in the micellar mode was found to be more appropriate for the analysis of hyoscyamine and scopolamine in plant material. These two compounds are generally found together with other tropane alkaloids which present similar structures and charge to mass ratio. Furthermore, the separation of positional isomers, such as hyoscyamine and littorine generally encountered in plant extracts, was also considered. The developed method was applied to the analysis of hairy root extracts of Datura candida x Datura aurea, Datura quercifolia and Hyoscyamus albus.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9919984&dopt=Abstract
Eur J Pharmacol. 1999 Jan 1;364(1):7-11.
Characterization of the muscarinic receptor subtype mediating pilocarpine-induced tremulous jaw movements in rats.
Mayorga AJ, Cousins MS, Trevitt JT, Conlan A, Gianutsos G, Salamone JD.
Department of Psychology, University of Connecticut, Storrs 06269-1020, USA.
Four muscarinic receptor antagonists with varying selectivities for the four pharmacologically-defined muscarinic receptor subtypes (M1-M4) were administered into the lateral ventricle to determine their relative potency in reducing tremulous jaw movements induced by i.p. injection of the muscarinic receptor agonist pilocarpine (4.0 mg/kg). All four muscarinic receptor antagonists reduced tremulous jaw movements in a dose-dependent manner, with the following rank order of potency: scopolamine > methoctramine > or = telenzepine > pirenzepine. This pattern is inconsistent with the rank order of affinity of these agents at the muscarinic M1 receptor, and is consistent with their rank order of affinity at muscarinic M2 or M4 receptors. Because tremulous jaw movements are related to striatal function, and the muscarinic M4 receptor is more predominant than the muscarinic M2 receptor as a post-synaptic receptor in striatum, the present results suggest that pilocarpine induces jaw movements due to muscarinic M4 receptor stimulation. In view of the hypothesized relation between parkinsonism and cholinomimetic-induced jaw movements, these data suggest that a centrally-acting muscarinic M4 receptor antagonist could be useful as an antiparkinsonian agent.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9920179&dopt=Abstract
Herbs and Pharmaceuticals Online ||
Hair Million herbal formula for hair loss and hair growth ||
Wellstreet online pharmacy for click-order prescription medications ||
Altace Online Pharmacy ||
Rx Drugs USA, Prescription Drugs Online Pharmacy ||
Insurance plans and information ||
Insurance policies for all purposes ||
Antibiotics and prescription medications online literature ||