Alterations of rat adipose tissue metabolism associated with dietary chromium supplementation

Net free fatty acid release from adipose tissue taken from male rats fed a stock diet unsupplemented with chromium was significantly greater than that from adipose tissue taken from chromium-supplemented rats. This enhanced net lipolysis was unaccompanied by any evidence of a compensatory increase in reesterification. Specifically, the glycerokinase-catalyzed direct phosphorylation of glycerol, which might have provided an alternate supply of alpha-glycerophosphate for reesterification in the absence of glycolytic production of alpha-glycerophosphate, was significantly reduced. These animals also showed an abnormal glucose tolerance response. In contrast, male rats fed a purified diet unsupplemented with chromium appeared to be marginally chromium-deficient as judged by a glucose tolerance test but did not show any alterations in adipose tissue metabolism attributable to the adequacy of chromium nutriture.