Insulin in insects: Analysis of immunoreactivity in tissue extracts

Abstract

1. 1. Insulin immunoreactivity and proteolytic activity in phosphate buffer and acid-ethanol extracts from larval heads and midguts of the mealworm were measured. 2. 2. These two types of extraction gave very different values of IRI in the same tissue. 3. 3. By the use of direct and indirect methods strong degradation of 125I-insulin by proteolytic enzymes active in neutral extracts was shown. 4. 4. Differences in IRI were due to interferences in radioimmunoassay caused by co-extracted proteolytic enzymes. 5. 5. It is not possible to determine IRI precisely in neutral extracts of insect tissues.