Drugs online research references
J Pharm Sci. 1989 Dec;78(12):995-8.
Intestinal absorption mechanism of dipeptide angiotensin converting enzyme inhibitors of the lysyl-proline type: lisinopril and SQ 29,852.
Friedman DI, Amidon GL.
College of Pharmacy, University of Michigan, Ann Arbor 48109-1065.
The intestinal absorption mechanism of two nonsulfhydril lysyl-proline angiotensin converting enzyme (ACE) inhibitors, lisinopril (1) and SQ 29,852 (2; [(S)-1-[6-amino-2-[[hydroxy (4-phenylbutyl)-phosphinyl]oxy[-1-oxohexyl]-L-proline) were investigated in rats using a single-pass perfusion method. Compound 2 is well absorbed from rat jejunum, whereas lisinopril absorption is relatively low. The permeability of both ACE inhibitors is concentration dependent and is decreased by the dipeptide Tyr-Gly and by cephradine, indicating a nonpassive absorption mechanism via the peptide carrier-mediated transport system. Compound 2 is well absorbed by a nonpassive mechanism, in parallel with a small passive component. The estimated dimensionless carrier parameters for 2 are J*max = 0.16, Km = 0.08 mM, P*c = 2.0, and P*m = 0.25; for lisinopril, passive absorption is not significant and its absorption is nonpassive: J*max = 0.032, Km = 0.082 mM, and P*c = 0.39 (where J*max is the maximal flux, Km is the Michaelis constant, P*c is the carrier permeability, and P*m is the passive permeability). These results offer a mechanistic explanation for the prolonged ACE inhibition and the low oral bioavailability of lisinopril, and for the nonlinear pharmacokinetics of 2.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2559191&dopt=Abstract
word match zestril online literature
Am J Physiol. 1999 Dec;277(6 Pt 1):L1245-50.
Fas-induced apoptosis of alveolar epithelial cells requires ANG II generation and receptor interaction.
Wang R, Zagariya A, Ang E, Ibarra-Sunga O, Uhal BD.
The Cardiovascular Institute, Michael Reese Hospital and Medical Center, Chicago, Illinois 60616, USA.
Recent works from this laboratory demonstrated potent inhibition of Fas-induced apoptosis in alveolar epithelial cells (AECs) by the angiotensin-converting enzyme (ACE) inhibitor captopril [B. D. Uhal, C. Gidea, R. Bargout, A. Bifero, O. Ibarra-Sunga, M. Papp, K. Flynn, and G. Filippatos. Am. J. Physiol. 275 (Lung Cell. Mol. Physiol. 19): L1013-L1017, 1998] and induction of dose-dependent apoptosis in AECs by purified angiotensin (ANG) II [R. Wang, A. Zagariya, O. Ibarra-Sunga, C. Gidea, E. Ang, S. Deshmukh, G. Chaudhary, J. Baraboutis, G. Filippatos and B. D. Uhal. Am. J. Physiol. 276 (Lung Cell. Mol. Physiol. 20): L885-L889, 1999]. These findings led us to hypothesize that the synthesis and binding of ANG II to its receptor might be involved in the induction of AEC apoptosis by Fas. Apoptosis was induced in the AEC-derived human lung carcinoma cell line A549 or in primary AECs isolated from adult rats with receptor-activating anti-Fas antibodies or purified recombinant Fas ligand, respectively. Apoptosis in response to either Fas activator was inhibited in a dose-dependent manner by the nonthiol ACE inhibitor lisinopril or the nonselective ANG II receptor antagonist saralasin, with maximal inhibitions of 82 and 93% at doses of 0.5 and 5 microg/ml, respectively. In both cell types, activation of Fas caused a significant increase in the abundance of mRNA for angiotensinogen (ANGEN) that was unaffected by saralasin. Transfection with antisense oligonucleotides against ANGEN mRNA inhibited the subsequent induction of Fas-stimulated apoptosis by 70% in A549 cells and 87% in primary AECs (both P < 0.01). Activation of Fas increased the concentration of ANG II in the serum-free extracellular medium 3-fold in primary AECs and 10-fold in A549 cells. Apoptosis in response to either Fas activator was completely abrogated by neutralizing antibodies specific for ANG II (P < 0.01), but isotype-matched nonimmune immunoglobulins had no significant effect. These data indicate that the induction of AEC apoptosis by Fas requires a functional renin-angiotensin system in the target cell. They also suggest that therapeutic control of AEC apoptosis is feasible through pharmacological manipulation of the local renin-angiotensin system.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10600897&dopt=Abstract
word match zestril online literature
Biometrics. 1987 Sep;43(3):713-8.
The statistical evaluation of a three-period two-treatment crossover pharmacokinetic drug interaction study.
Ciminera JL, Bolognese JA, Gregg MH.
Merck Sharp & Dohme Research Laboratories, West Point, Pennsylvania 19486.
In a pharmacokinetic drug interaction study, the purpose is to determine whether the coadministration of a drug A with a second drug B alters the absorption/distribution/metabolism/elimination profile of either drug. While the usual design for such studies is a three-period crossover, it cannot be analyzed as such, because the plasma-level data of drug B will be 0 when drug A is given alone, and vice versa. The easiest way to proceed is to do two sets of paired analyses, one on the absorption profile of A (A vs AB), and the other on the absorption profile of B (B vs AB). A complete separation of the total sources of variation and degrees of freedom is presented along with a numerical example.
online pharmacy ref source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2822158&dopt=Abstract
word match zestril online literature
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