Role of Rat Liver in Nonshivering Thermogenesis.

Abstract

Liver blood flow, oxygen consumption, liver and rectal temperatures, and oxygen tension of liver were studied in cold-adapted and warm-adapted rats whose muscular activity was blocked by curare. Liver blood flow was measured by the blood clearance of radioactive chromic phosphate injected intravenously. No difference in temperature between rectum and liver was found in any rat in either group. Liver blood flow in cold-adapted rats did not differ from that in warm-adapted ones so long as the tests were performed in a warm room (30[degree]C). However, liver blood flow was considerably greater in cold-adapted than in warm-adapted rats when the room was cooled from 30[degree] C to 5[degree] C, although the increase was not sufficient to account for the excess oxygen consumption.