Mesenteric Arteries of Spontaneous Diabetic BB Rats

Mesenteric arteries were isolated from the spontaneous diabetic BB rats, non-diabetic BB rats and regular Wistar control rats. Gross morphology indicated that the mesenteric vascular bed of the control Wistar rats hacl a normal development of mesenteric fat pad around the vessels, while that of the diabetic BB rats showed drastically reduced perivascular fat pad, suggesting greater mobiTization of fat for energy censumption in the hyperglycemic state of diabetes mellitus. The perivascular mesenteric fat pad of the non-diabetic BB rats was intermediate between those oi the Wistar control and diabetic BB rats. The wet weight of the mesenteric arteries following removal of fat, vein and connective tissues was significantly greater in diabetic BB rats than in the corresponding controls, Microsomal membranes isolated from the mesenteric arteries of diabetic BB rats showed increased alka]ine phosphatase and 5'-nucleotidase activities compared to those isolated from the two groups of non-cliabetic control rats. Acid phosphatase activities were higher in both BB rat groups comparecl to the Wistar group. The total Ca2' uptake by the microsornes of mesenteric arteries in the presence of ATP was not clifferent among three experimentar groups, but the ATP-dcpendent active transport of Ca2' was significantly increased and the passive Ca2' binding was significantly reduced in diabetic group compared to the other two non-diabetic groups. Our results clemonstrate that in the spontaneously diabetic BB rats, alterations in both structural and functional parameters may underline the vascular complications associated with type I diabetes mellitus in humans.