http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-104290 The Concentration of b-Carotene in Human Adipocytes, but Not the Whole-Body Adipocyte Stores, Is Reduced in

Abstract

We have examined the concentration of b-carotene in the fat of isolated abdominal subcutaneous adipocytes obtained from lean (BMI,23 kg/m 2), non-obese with higher BMI (23#BMI,28 kg/m 2), obese (BMI$28 kg/m 2), and from a group of obese subjects with type 2 diabetes. The concentration of b-carotene was 50 % lower in the adipocytes from the obese and obese/diabetic groups compared with the lean and non-obese groups. Interestingly, the total amount of b-carotene in the adipocyte stores of each subject was constant among all groups. Triacylglycerol constituted 9261 % (by weight) of the adipocyte lipids in the lean group and this was increased to 9962 % in the obese group with diabetes (p,0.05). The concentration of cholesteryl esters was in all cases,0.1 g per 100 g of total lipids, demonstrating that mature human adipocytes have negligible stores of cholesteryl ester. Our findings demonstrate that adipocyte concentrations of b-carotene are reduced in obese subjects. The lower concentrations in adipocytes from subjects with type 2 diabetes apparently reflect subjects obesity. Our finding that whole-body stores of b-carotene in adipocytes are constant raises new questions regarding what function it serves, as well as the mechanisms for maintaining constant levels in the face of varie