Insulin secretion by the pancreas of the chick embryo

Summary

Insulin activity of chick embryo plasma was determined by tests on an isolated rat diaphragm. The blood from several embryos was mixed; the plasma was separated by centrifugation, and was diluted 10 times with salt solution containing 300 mg% of glucose. The glucose absorption was expressed as micrograms per 10 mg (dry weight) of the diaphragm per 90 minutes. The insulin effect was measured by the difference between the amount of glucose absorbed by one of the halves of the diaphragm, immersed in a test solution, and the amount absorbed by the other half immersed in pure glucose solution. It was found that insulin did not appear in the plasma of the chick embryo until the 13th day. The insulin activity of plasma diluted 10 times was approximately 0.1–10μ units per ml.