Effect of insulin on small intestinal transit in normal mice is independent of blood glucose level

Abstract

BackgroundInsulin is the drug of choice in the management of diabetes mellitus (DM). About 76 % of diabetic patients suffer from gastrointestinal (GI) disorders. Therapy of DM with insulin primarily involves lowering of elevated blood glucose levels. Hence, on any organ in addition to insulin's effect, hypoglycaemic effect also prevails. A systematic study exploring the effect of insulin on small intestinal transit in normal laboratory animals is lacking. Hence, in the present study, the possible effect of insulin with or without associated hypoglycaemia on small intestinal transit in normal mice was examined.ResultsInsulin in all the doses tested (2 μ, 2 m and 2 U/kg) elicited a significant acceleration of SIT. The lower doses of insulin (2 μ and 2 m U/kg) produced significant acceleration of SIT and were associated with normal blood glucose levels. However, the highest dose of insulin (2 U/kg) produced an acceleration of SIT that was associated with significant fall in blood glucose levels. Further, the 2 m and 2 U doses of insulin significantly elevated serum insulin and C-peptide levels.ConclusionInsulin at the lowest dose produced an acceleratory effect on SIT that was independent of blood glucose and serum insulin levels in normal mice.

Infestation of a novel host plant by Tephritis conura (Diptera: Tephritidae) in northern Britain: host-range expansion or host shift?

“…Such host-range expansions will often increase the geographic distribution of the infesting insect, and in the event of extinction and/or removal of the alternative host(s) it may be a first step in speciation (e.g. Janz et al 2006). Two major insights emerged from this study.…”

“…Speciation via host-range expansion and host shift are not mutually exclusive. Host-range expansions may increase the geographic range of phytophagous insects, which may, following fragmentation, specialise on different plants in isolation (Päivinen et al 2005;Janz et al 2006). The geographic distribution of interaction can therefore be used to generate hypotheses about modes of specialisation (Thompson 1994).…”