Insulin requirements for hepatic regeneration following hepatectomy.

On the basis of changes in the adenine nucleotide the mitochondrial metabolism of the remnant liver, insulin requirements for hepatic regeneration were studied in diabetic rats treated with varying amounts of alloxan. Mildly diabetic rats with less than 30% inhibition in maximal portal insulin response to oral glucose load, showed a parabolic glucose tolerance pattern and could tolerate partial hepatectomy. Whereas, severely diabetic rats with more than 45% inhibition showed a linear glucose tolerance pattern and died within 24 hours after partial hepatectomy. In the former rats, the energy charge (ATP + 1/2ADP/ATP + ADP + AMP) levels of the remnant liver decrease slightly at an early period after partial hepatectomy but could be restored rapidly to normal levels with a concomitant rise of oxidative phosphorylation in remnant liver mitochondria. In contrast, the energy charge levels in the latter groups fell more markedly and could not be restored, because of insufficient enhancement of mitochondrial oxidative phosphorylation. It is suggested that an enhancement in mitochondrial phosphorylative activity of the remnant liver following partial hepatectomy is inhibited in proportion to the severity of impaired insulin secretion, resulting in a decrease of the potential functional capacity of liver.