Age and thyroid hormone as factors in the responses of BHE rats to starvation-refeeding.

The interacting effects of thyroid hormone, age, and duration of starvation on the enzyme and liver lipid responses of BHE rats to starvation-refeeding were studied. Rats were starved for 2, 4, or 7 days and refed a 65% glucose diet for 2 days. The rats were either 150 or 420 days of age and injected daily with either saline or 10 micrograms thyroxine/100 g body weight. Neither age nor duration of starvation affected the glucose-6-phosphate dehydrogenase or malic enzyme activity or liver lipid response to starvation-refeeding. However, thyroxine treatment potentiated the response to starvation-refeeding in the 420-day-old rats when the duration of starvation increased from 2 to 7 days.