Increased uptake of insulin and glucagon by the liver as a signal for regeneration.

We have determined the pancreatic output and the hepatic uptake, per gram of liver, of insulin and glucagon before and after both a 42 and a 72 per cent hepatectomy in dogs. Pancreatic output and hepatic uptake were determined from the hormonal concentration, as measured by radioimmunoassay, and the blood flows in the portal vein, hepatic artery and hepatic vein measured with an electromagnetic flowmeter. There was no significant difference in the output of either insulin or glucagon by the pancreas after hepatectomy. Likewise, peripheral concentrationof insulin and glucagon did not change significantly. The uptake of each hormone by the liver was a function of the amount delivered to the liver both before and after hepatectomy. After a 72 percent hepatectomy, there was a statistically significant increase in uptake per gram of liver for both insulin and glucagon, p less than 0.005, when compared with the uptake before hepatectomy. During this time, the plasma glucose concentration fell. The immediate increase in the uptake, per gram of remaining liver, of insulin and glucagon may be a signal for regeneration in terms of rapid augmented binding or degradation by liver cell receptor sites.