Insulin receptor and IGF-I receptor Bioactivity in Health and Disease
Year: 2013
Type: dissertation
Abstract: Insulin was discovered in 1921 by Banting and Best and its structure elucidated in \n1955. The first insulin bioassays appeared in the 1940s. First, rats were injected with \na range of known concentrations of purified commercial or ‘standard’ insulin and the \nsubsequent fall in blood glucose levels was measured. Then an unknown sample of human \nplasma was administered to a rat and its insulin concentration was assumed to be \nidentical to the standard dilution that caused the same fall in glucose levels. Due to \npoor correlations between measured blood glucose levels and calculated insulin levels, \nthese bioassays were replaced by in vitro bioassays. Metabolic parameters, such as rate \nof glucose uptake in response to dose-response curves of known insulin concentrations \nwere measured using isolated tissues, such as the hemidiaphragm or epididymal fat pad \nfrom the rat. Also these in vitro bioassays for plasma insulin were not very successful \ndue to high inter-assay variability, their laborious nature and due to a growing doubt \nthat they were not specific for insulin. Maybe even more importantly, in 1959 Leonards \ndescribed a substance in normal human fasting serum that, like insulin, stimulated \nglucose oxidation and triglyceride synthesis in adipose tissue but that, unlike insulin, \ncould not be extracted from plasma into acid-ethanol. In 1963, Froesch et. al. found \nthat serum from guinea pigs immunized against insulin, suppressed insulin action in \nfat tissue, but it had no effect on Leonards’s insulin-like substance and so the term nonsuppressible \ninsulin like activity (NSILA) was born.
Author: Aimee J. Varewijck
Language: English
Subfield: Endocrinology, Diabetes and Metabolism
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2169973712