Abnormal taurocholate ileal transepithelial transport in atherosclerotic mini-pigs and effects of ACE inhibitors.

In atherosclerotic mini-pigs, we attempted to determine (i) whether high-fat atherogenic diet disturbs the taurocholate transepithelial transport and incorporation in the ileal epithelium mounted in Ussing chambers, and (ii) whether these processes are sensitive to angiotensin converting enzyme (ACE) inhibitors which slow the development of vascular atherosclerosis. In atherosclerotic mini-pigs, the mucosal to serosal transepithelial fluxes were markedly lower (72% inhibition) and free diffusion was more altered than active processes. Taurocholate incorporation into enterocyte (75% inhibition) paralleled the flux reduction.

Human hepatic uptake of two vinca alkaloids: navelbine and vincristine.

A human liver plasma membrane model for the evaluation of the specific binding and transport processes of drugs presenting high hepatic clearance such as vinca alkaloids was developed. Uptake of the two structural antitumor analogs, navelbine (NVB) and vincristine (VCR), which exhibit wide variabilities in their respective pharmacokinetic parameters and antitumor spectra, was investigated. The high yield, the enzymatic profile and the retention of physiologic transport capacities, as demonstrated by taurocholate uptake, revealed that this membrane preparation was well suited for studies of hepatic drug transport systems.

Intestinal absorption of drugs: digitalis binding and transport by brush-border membrane vesicles from human duodenum.

The intestinal epithelial cell layer is the first major barrier to absorption encountered by xenobiotics. An understanding of the mechanism and sites of drug absorption and metabolism is thus a critical first step in developing orally active compounds. In this context human brush-border membrane vesicles obtained from multi-organ donor intestines have been purified.

[The effect of pentoxifylline and propentofylline on the membrane fluidity of red blood cells in uncontrolled insulin-dependent (type 1) diabetic patients].

Fluorescence polarization of red blood cell (RBC) membranes evaluated using DPH was measured in patients with uncontrolled insulin-dependent diabetes mellitus and in controls. The effect of in vitro addition of pentoxifylline and propentofylline (10(-5) and 10(-4) M) was studied. The fluorescence polarization parameter (P) was lower in the diabetic patients (p = 0.

In vivo insulin effect on ATPase activities in erythrocyte membrane from insulin-dependent diabetics.

Na+-K+-dependent ouabain-sensitive ATPase and Mg2+-ATPase have been assayed in the erythrocyte membranes of control subjects and in uncontrolled type I (insulin-dependent) diabetics. A decrease in Na+-K+-ATPase activity was observed in the patients that was significantly correlated with glycemia. The Mg2+-ATPase was increased moderately, and no correlation with glycemia was found.