Improvement of insulin response in the streptozotocin model of insulin-dependent diabetes mellitus.: Insulin response with and without a long-acting insulin treatment
2009 (English)In: Animal, ISSN 1751-7311, Vol. 3, no 5, 685-689 p.Article in journal (Refereed) Published
Streptozotocin-induced diabetes mellitus (STZ-DM) in rats is a model of type 1 diabetes, which is commonly used to study diabetes, but differs from human diabetic pathophysiology in its insulin resistance, An STZ-DM rat can be administered five times the dose of insulin compared to that of a diabetic patient. Thus, attaining normoglycaemia in STZ-DM rats with insulin injections is complicated, and it involves an obvious risk of overdosing before getting a response. This study was designed to investigate whether suboptimal treatment with long-acting insulin restores insulin sensitivity in the STZ-DM rat, and thus an approach to more closely mimic the human condition. Male Sprague-Dawley rats were made diabetic by means of a single intravenous injection of STZ (55 mg/kg body weight (BW)), resulting in an increase in blood glucose (BG) from 6.5 +/- 0.2 to 22.5 +/- 1.0 mmol/l (P <= 0.05) within 24h. After treating the STZ-DM rats with vehicle for 14 days, BG was 26.1 +/- 1.1 mmol/l, and the response to a single injection of fast-acting insulin (Humalog, 5 IE/kg BW) was a 23% reduction in BG. Thereafter, the rats were treated daily with a suboptimal dose of long-acting insulin for a total of 7 days (Insulatard, 5 IE/kg per day), which resulted in a BG level of 19.4 +/- 2.7. The response to fast-acting insulin after the suboptimal treatment was a 61% reduction in BG. Thereafter, the animals were vehicle-treated for another 7 days, which resulted in a response to fast-acting insulin similar to the initial values (-34%). Furthermore, the group treated with suboptimal doses of long-acting insulin had a longer duration of the reduction in BG (150 min, as opposed to 90 min in the vehicle-treated groups). We conclude that the development of a decreased insulin response occurs rapidly within the first 2 weeks after the onset of diabetes in STZ-DM rats. This leads to a brief and significantly reduced decrease in BG when tast-acting insulin is administered, The insulin response is increased by treatment with suboptimal doses of long-acting insulin, but rapidly decreases again when treatment is withdrawn. Regular administration of suboptimal insulin doses may provide an approach to eliminate the effects of a lowered insulin response.
Place, publisher, year, edition, pages
Cambridge university press , 2009. Vol. 3, no 5, 685-689 p.
insulin response, reversal, STZ-DM, diabetes, animal model
Medical and Health Sciences
Research subject Physiology
IdentifiersURN: urn:nbn:se:uu:diva-119872DOI: 10.1017/S175173110800387XISI: 000265335600008OAI: oai:DiVA.org:uu-119872DiVA: diva2:301103