Decreased skin blood flow early in the course of streptozotocin-induced diabetes mellitus in the rat

Abstract

We have previously used laser Doppler technology to demonstrate that skin blood flow is reduced in Type 1 (insulin-dependent) diabetic patients. The possibility of using the skin as an extremely accessible indicator of diabetic microvascular disease is attractive. The streptozotocin diabetic rat is an appealing potential animal model. We performed measurements of skin blood flow in two rat species, nine Sprague Dawley (SD) rats and nine Wistar Kyoto (WKY) rats, observing early changes following the inception of diabetes. Four of the SD rats and five of the WKY rats were made diabetic, the rest serving as controls. There were no significant differences in skin blood flow between the two rat strains. As in man, there appear to be rat skin sites with primarily nutritive capillary supply and those with arteriovenous anastomotic predominance. The back and base of tail, both hair-covered areas, demonstrated low flow characteristics, consistent with nutritive perfusion. In contrast, the plantar surface of the paw behaved similarly to the finger or toe pulps in man, sites of arteriovenous perfusion, with high basal flow and a marked increment with thermal stimulation. In diabetic rats of both species, there was significantly lower flow at the back and base of tail than in non-diabetic animals. The differences were of the order of 30-40%. As a function of time, the decrease in blood flow at the base of tail parallelled the increase in glycohaemoglobin levels in the diabetic rats. In contrast, blood flow at the plantar surface of the paw was unchanged throughout the 3-month post-streptozotocin observation period.(ABSTRACT TRUNCATED AT 250 WORDS)

Polychromatic LED in Oval Full-Thickness Wound Healing in Non-diabetic and Diabetic Rats

“…Diabetic wounds tended to exhibit less bleeding, implying a defect in the peripheral circulation, consistent with the findings of Rendell et al, 7 who showed that skin blood flow early in the streptozotocin-induced diabetic rats was decreased by 30-40%. The defect of micro-circulation in the skin and subcutaneous tissue impairs wound healing through the decreased delivery of nutrients, oxygen, and immune cells to initiate and sustain the reparatory process.…”

Polychromatic LED Therapy in Burn Healing of Non-diabetic and Diabetic Rats

“…The prolongation of inflammatory response was consistent with the findings of Wetzler et al 6 that macrophage-inflammatory protein-2/mRNA together with the macrophage-chemoattractant-protein-1/ mRNA expressions were extended and directly associated with sustained infiltration, but with different localization of PMN and macrophages in the diabetic wound. It was also found out by Rendell et al 7 that skin blood flow early in the streptozotocin-induced diabetic rats was decreased by 30-40% as a function of time paralleling the increase in glycated hemoglobin. This defect in microcirculation leads to the delay of inflammatory cells reaching the burn site, aggravated by the blocking of capillaries (by coagulated proteins and cellular debris) that needs to be cleared out.…”

Effects of the protein kinase Cβ inhibitor LY333531 on neural and vascular function in rats with streptozotocin-induced diabetes

“…In the present study, LY333531 treatment corrected thermal hyperalgesia without having any effect on mechanical thresholds, which suggests a specific action rather than a general anti-allodynic or central analgesic effect. The thermal anti-nociceptive action could relate to increased nerve\ganglion blood flow or to improvements in skin perfusion in the vicinity of sensory nerve terminals [43], a hypothesis that is testable using peripheral vasodilator treatment. The lack of an effect on mechanical nociception thresholds, which are correctable with insulin treatment [40], suggests that a PKCβ-mediated vascular mechanism is not critically important.…”