Drugs online research references
Biochem Biophys Res Commun. 1993 Sep 15;195(2):997-1004.
Omeprazole, a proton pump inhibitor, reduces the secretion, synthesis and gene expression of pepsinogen in the rat stomach.
Kakei N, Ichinose M, Tsukada S, Tatematsu M, Tezuka N, Yahagi N, Matsushima M, Miki K, Kurokawa K, Takahashi K, et al.
First Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
Omeprazole, a proton pump inhibitor, dose-dependently inhibited pepsinogen secretion as well as acid secretion in the rat glandular stomach. The reduction in the secretion was rapid and was followed by a decrease in the mRNA levels. The inhibitory effect of omeprazole on pepsinogen secretion and its effect on the mRNA level showed similar dose-response relationship, suggesting that pepsinogen secretion and the gene expression are regulated coordinately. Consistent with the reduction in the mRNA levels, protein synthesis was reduced. However, intracellular stores of pepsinogen increased in pepsinogen-producing cells, indicating that the inhibitory effect of omeprazole on pepsinogen secretion is greater than on its synthesis. Reducing the secretion, synthesis and gene expression of pepsinogen, omeprazole has a potent effect on pepsinogen-producing cells in vivo, as well as on parietal cells, in the rat glandular stomach.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=7690564&dopt=Abstract
note: kwd match prilosec online literature
Xenobiotica. 1997 Jan;27(1):49-58.
Selectivity of omeprazole inhibition towards rat liver cytochromes P450.
Zomorodi K, Houston JB.
Department of Pharmacy, University of Manchester, UK.
1. The potency and selectivity of omeprazole as an inhibitor of cytochrome P450-mediated drug oxidations has been assessed in hepatic microsomes from the untreated, phenobarbitone-treated, beta-naphthoflavone-treated and dexamethasone-treated rat. Using the marker substrates diazepam, ethoxycoumarin, ethoxyresofurin and ethylmorphine in the above microsomal preparations, inhibitory activity against CYP1A, 2B, 2C and 3A members of the cytochrome P450 superfamily were determined. 2. In each situation studied the kinetics of inhibition by omeprazole were competitive in nature with Ki's ranging from 25 to > 1000 microM. Marker activities for the 3A family in microsomes from the dexamethasone-treated and phenobarbitone-treated rat (3-hydroxylation of diazepam and N-demethylation of ethylmorphine) were most susceptible to omeprazole inhibition (Km/Ki ratios greater than unity) compared with marker activities for the CYP1A, 2B and 2C sub-families (Km/Ki ratios < or = unity). 3. Omeprazole sulphoxide showed similar potency and selectivity of inhibition to its parent drug. Analogous studies with the same marker activities using ketoconazole indicated that both omeprazole and its sulphoxide metabolite are less potent as an inhibitor of cytochrome P4503A in rat than this well characterised prototype.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9041678&dopt=Abstract
note: kwd match prilosec online literature
Am J Physiol. 1993 Nov;265(5 Pt 2):F698-704.
H(+)-K(+)-ATPase of rat inner medullary collecting duct in primary culture.
Kleinman JG, Tipnis P, Pscheidt R.
Nephrology Division, Zablocki Veterans Affairs Medical Center, Milwaukee, Wisconsin.
pH recovery in response to addition of and removal from NH4Cl was examined using 2',7'-bis(2-carboxy-ethyl)-5(6)-carboxyfluorescein fluorescence in primary cultures of inner medullary collecting duct (IMCD) cells from rat kidneys. In 0 K+, pH recovery rate was 0.012 +/- 0.010 U/min; in 5 mM K+, the recovery rate was greater at 0.065 +/- 0.013 U/min (P = 0.026). The H(+)-K(+)-adenosinetriphosphatase (H(+)-K(+)-ATPase) inhibitors omeprazole and Sch-28080 and the P-type ATPase inhibitor vanadate significantly inhibited pH recovery at 100, 10, and 5 microM, respectively. The vacuolar H(+)-ATPase inhibitor bafilomycin failed to inhibit pH recovery, but N-ethylmaleimide (NEM) did. A range of Sch-28080 concentrations inhibited ouabain-resistant ATPase activity of microsomes from these cells in a reverse sigmoidal manner, with little inhibition < 1 microM, virtually 100% inhibition > 100 microM, and a 50% inhibitory concentration of approximately 20 microM. Bafilomycin only produced significant inhibition of activity at concentrations well in excess of those that are effective against the vacuolar H(+)-ATPase. The ouabain-resistant ATPase activity in cultured IMCD was also sensitive to vanadate (90% inhibition with 5 microM) but relatively resistant to N,N'-dicyclohexylcarbodiimide and NEM. These results indicate that pH regulation in primary cultures of IMCD cells, presumably reflecting H+ transport, is predominantly due to an H(+)-K(+)-ATPase.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8238550&dopt=Abstract
note: kwd match prilosec online literature
Herbs and Pharmaceuticals Online ||
Hair Million herbal formula for hair loss and hair growth ||
Antibiotics and prescription medications online literature ||