Objective To observe the effects of 1,3-dipropyl-8-cyclopentylxanthine(DPCPX),an adenosine A1 receptor antagonist,on brain neurons damage induced by hypoxia and reoxygenation(H/R),and to elucidate the relevant mechanisms.Methods An in vitro cultured rat cerebral cortical neuronal H/R damage model was established;the effects of DPCPX were detected at final concentrations of 0(control),25,50,100nmol/L on the lactate dehydrogenase(LDH) release from normoxic neurons and H/R neurons which were treated with hypoxia for 8,12,24 hours followed by reoxygenation for 24 hours;the changes of malondialdehyde(MDA) content,activities of xanthine oxidase(XO) and Ca2+-ATPase in H/R neurons which were treated with hypoxia for 12 hours and reoxygenation for 24 hours brought by administration of DPCPX at the concentration of 100nmol/L were also determined by use of specific reagents.Results With addition of 100nmol/L DPCPX,the LDH release from H/R neurons which were treated with hypoxia for 12 hours and reoxygenation for 24 hours was significantly increased compared with that in control group(P

AIM To investigate the effects of the novel compound pivanampeta on the fatty liver induced by cholesterol-feeding in rabbits and quails. METHODS ①24 male rabbits were divided into four groups randomly as following: control group, model group, pivanampet 1 and 5 mg?kg -1 groups. The serum levels of total cholesterol were determined after the rabbits were cholesterol-fed for 12 weeks. The morphological changes of liver were observed. The levels of cholesterol and malonal-dialdehyde and the activities of glutatione peroxidase in the homogenate of liver were also measured.②181 male quails were divided into six groups randomly:control group, model group, Simvastatin 5 mg?kg -1 group, pivanampet 3,6 and 9 mg?kg -1 groups. The serum levels of total cholesterol were determined after the quails had been fed with cholesterol diets for 11 weeks. After 14 weeks part of the animals were killed, the morphological changes of liver were observed. The hepatic coefficient were determined after the remaining quails were cholesterol-feeding for 18 weeks. RESULTS Pivanampet alleviated the liver Steatosis induced by cholesterol-feeding in rabbits and quals. It decreased total cholesterol levels, elevated the activity of glutatione peroxidase in the rabbits liver, and reversed the increasing hepatic coefficient in rabbits and quails. CONCLISION The novel compound Pivanampet can delay the formation of fatty liver by cholesterol-feeding.

Due to the completion of human genome project and the advent of new technologies, the traditional drug discovery is shifting to genomics-based drug discovery. Target discovery is an important first step in drug discovery pipeline. In this review, we critically introduce the strategies and biology technologies for target discovery, especially focus on the likely impact of new technologies in drug target research and speculate the future trend of target research.

There is another factor involving in endothelium dependent relaxation besides NO, which is independent of cGMP, EDHF. Its hyperpolarization mechanism may be related to the open of calcium dependent K + channels(K + Ca). NO, PGI 2,H 2O 2 and cytochrome P450 derived metabolite of arachidonic acid are all the candidates of EDHF. In the normal blood vessels, the influence of EDHF on endothelium dependent relaxation is little. But in some diseases, when the production and effect of NO is disturbed ,the mechanism of EDHF may play a specially important role.

It is well documented that vascular tone is the key determinant of blood vessel resistance and blood flow. But vascular tone could be regulated by modulating the activity of potassium channel directly. Potassium channel openers promote vasodilation by inhibiting the activity of voltage dependent calcium channels and reducing Ca 2+ influx. In this case, inhibition results from membrane hyperpolarisation, which arises due to the stimulation of K + efflux through smooth muscle K + channels. While K + channels are blocked, vasoconstriction could be observed as a result of membrane depolarization, which opens voltage dependent calcium channels. The influx of Ca 2+ can promote smooth muscle contraction by making myosin light chain phosphorylation and arising thick myofilament and thin myofilament relative movements. In this article, the gene structure, current character, Pharmacological and physiological effects of the four subtypes potassium channels are reviewed.

ATP sensitive potassium channels (K ATP ) have been thought to be a mediator of cardioprotection. Recent pharmacologic and molecular biology studies show the protective effects of K ATP openers are not dependent of action potential shortening and cardiodepressant effects, but mediated by preservation of mitochondrial function, which suggests a role for intracellular mitochondrial K ATP (mito K ATP ). The mechanism by opening mito K ATP produces cardioprotection is less clearer, however, it is thought that a beneficial effect may occur as the result of K + entry and intramitochondrial depolarization. This effect would reduce mitochondrial calcium overload and cause matrix swelling, which are shown to enhance ATP synthesis and stimulate mitochondrial respiration.

AIM To investigate the protective effects of iptakalim hydrochloride (Ipt) against glutamate induced neurotoxity. METHODS Neurotoxity injury was induced by with glutamic acid in PC12 cells. The cell viability was measured by MTT assay. RESULTS Ipt at the concentrations of 1 ? 1(T-10 - 1 ? 1(T4 mol ? L-1 markedly mitigated glutamate-induced neurotoxicity. The protec- live effect was nullified by glibenclamide, an ATP-sensitive potassium channel antagnist. CONCLUSION Ipt provides neuroprotection on glutamate-induced cytotoxixity in cultured PC12 cells and this effect may be related with ATP-sensitive potassium channels.

ATP sensitive potassium channel(K ATP has been indentified in a variety of tissues and recognized as an important drug target.K ATP channels is composed with a 4∶4 stoichiometry of an inwardly rectifying K + channel(Kir) subunit plus a sulfonylurea receptor(SUR).The characteristics for the SUB2B/Kir 6 1 in vascular are small condutance,ATP insensitivity and activation by added NDP.Therefore,it is refered as NDP dependent K + channel(K NDP ).A lot of endogenous and exogenous vasodilators seem to act through a common pathway by opening K ATP in vascular,which is involved in protein kinase A and C signal transduction pathway.Vascular shows different sensitivity to potassium channel openers(KCO),and the mechanism remains to be determined.In this review,a summary of K ATP in vascular is presented with molecular structure,KCO selectivity to tissue,signal pathway,electrophysiological and pharmacological properties.

Aim To clone the muscarinic receptors M1, M3 and M5 sequences of astrocyte cells,and compare the gene and protein sequences with those of neurons. Methods Specific primers were designed to clone the M1, M3 and M5 sequences of astrocyte cells by RT-PCR according to those of neurons,then sequenced the sequences. Result By comparing the M1, M3 and M5 sequences expression by astrocyte cells with those by neurons and we found four, eight,and one different bases and one, four and one different amino acids in M1, M3 and M5 between astrocyte cells and neurons respectively. Conclusions The gene and protein sequence differences are evident in M1, M3 and M5 between astrocyte cells and neurons.