Distribution of 14C-Gentamicin in Vascular Smooth Muscle

Publisher Website
Google Scholar
Abstract
The distribution and movements of 14C-gentamicin were examined in rabbit aortic smooth muscle under a variety of conditions. Uptake of 14C-gentamicin reached a maximum value within 20 min. As the Ca2+ concentration in the incubation solution was increased to 10 mM, 14C-gentamicin tissue uptake was decreased significantly. Uptake of 14C-gentamicin was also inhibited by La3+ (1.5 mM) and high K+ (80 mM). Efflux of 14C-gentamicin was increased in a maintained manner by exposure to either nonradioactive gentamicin or high K+. Pretreatment with metabolic inhibitors (iodoacetic acid and dinitrophenol) did not alter either uptake or efflux of 14C-gentamicin. Lowering the temperature of the incubation solution (to 0 °C) did not alter 14C-gentamicin uptake. These findings indicate that, in rabbit aortic smooth muscle, gentamicin uptake appears to be confined to superficial (surface accessible) sites. This further supports the idea that aminoglycoside antibiotics do not enter the cell in significant quantities and therefore induce cardiovascular depressant effects by altering Ca2+ uptake.

This publication has 1 reference indexed in Scilit: