Abstract
Marked difference between immuno reactive insulin in blood and insulin-like activity by adipose tissue method was investigated. ILA (insulin-like activity) and IRI (immuno reactive insulin) were compared for the thoracic duct lymph of dog and human body fluids of various origin. The results were as follows:
1) The ILA/IRI of the thoracic duct lymph of dog was about 6.5. After gel filtration of the lymph with Sephadex G 50, the ILA/IRI ratio of Fr. A with high protein concentration was about 6.5, while that of Fr. B with very little protein was less than 3.1.
2) The changes in IRI in the thoracic duct lymph after intravenous injection of glucose reflected the changes in IRI in blood with a delay of about 10minutes.
3) The IRI in human body fluid was fairly similar with that of serum. ILA was low in the fluid with low protein concentration and a correlation was observed between ILA and protein concentration.
From these results, it was suggested that IRI may pass through the capillary wall fairly freely and reach the peripheral tissues, while there was only little ILA in the dog lymph and human body fluids as assayed by the fat pad method.