Effect of mild cold exposure on whole-body and net hindquarters glucose metabolism in sheep

Isotope dilution using [U-13C]glucose was combined with measurement of hindquarters arteriovenous difference and blood flow to examine the effect of mild cold exposure on whole-body and net hindquarters glucose metabolism in sheep. Determinations were carried out in a thermoneutral environment (20 +/- 1 degrees C) and on day 5 of mild cold exposure (4 +/- 1 degrees C). Whole-body blood glucose turnover rate was 1.56 and 1.91 mg kg-1 min-1 in the thermoneutral environment and during mild cold exposure, respectively. Net hindquarters glucose uptake was 0.79 and 1.19 mg kg-1 min-1, corresponding to 50 and 61% of whole-body turnover rate, respectively. These results suggest that in sheep the contribution of glucose uptake by the hindquarters tended to increase during mild cold exposure, even though whole-body blood glucose turnover rate did not increase significantly.