Effects of Glucose on Proinsulin Messenger RNA in Rats In Vivo
| Autor: | M. A. Permutt, S. J. Giddings, Chirgwin John Mitchell |
|---|---|
| Rok vydání: | 1982 |
| Předmět: |
Blood Glucose
endocrine system medicine.medical_specialty Endocrinology Diabetes and Metabolism medicine.medical_treatment Biology chemistry.chemical_compound Biosynthesis In vivo Complementary DNA Internal medicine Internal Medicine medicine Animals Insulin RNA Messenger Saline Proinsulin Messenger RNA Dose-Response Relationship Drug RNA Rats Inbred Strains Rats Endocrinology chemistry Dactinomycin hormones hormone substitutes and hormone antagonists |
| Zdroj: | Diabetes. 31:624-629 |
| ISSN: | 1939-327X 0012-1797 |
| DOI: | 10.2337/diab.31.7.624 |
| Popis: | The purpose of these studies was to determine whether glucose, the principal regulator of insulin biosynthesis in mammals, controls synthesis through alterations in levels of proinsulin mRNA in whole animals. Rats were starved for 3 days and then either refed or injected with glucose or saline for 24 h. Glucose injection raised plasma glucose levels equivalent to levels seen with refeeding but provided less than 20% of caloric replacement. Pancreatic RNA was extracted and the relative concentration of proinsulin mRNA was determined by blot hybridization with a cloned rat proinsulin cDNA probe. In starved animals proinsulin mRNA levels were 15–20% that of fed controls. Glucose injection produced a specific three- to fourfold increase in proinsulin mRNA levels relative to total pancreatic RNA, within 24 h. The effect was measurable 2 h after glucose injection and appeared largely complete by 12 h. Actinomycin D blocked the glucose-induced increase in proinsulin mRNA. These studies demonstrate effects of changes of plasma glucose on levels of proinsulin mRNA. Their rapidity of onset and large magnitude are comparable to effects of glucose on rates of insulin biosynthesis in isolated islets and suggest that insulin biosynthesis is regulated at least in part by levels of proinsulin mRNA. |
| Databáze: | OpenAIRE |
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