Effects of SH-reagents of different molecular size upon glucose metabolism in isolated rat fat cells.

To study the role of membrane SH-groups in glucose transport of isolated rat fat cells we compared the effects of a small organic mercurial reagent p-CMB with those of a large p--CMB-derivative -- p-CMB-Dextran, MW 10.000 --. It could be shown that both compounds were of almost identical reactivity on fat cell homogenate metabolism. When applied to intact fat cells uncoupled p--CMB showed an (1) insulin like enhancement of 14C incorporation from (U-14C) glucose into CO2 and triglyceride, (2) inhibition of the insulin-stimulatory effect on these parameters and (3) inhibition of basal glucose uptake dependent on the concentrations used. Identical concentrations of p-CMB-Dextran, however, failed to influence basal glucose uptake as well as the insulin mediated increase in glucose metabolism.