The early microvascular consequences of streptozotocin-induced diabetes in adult mice were evaluated. Streptozotocin (200 mg/kg) was used to induce diabetes at age 22-24 wk and the animals were studied at age 32-36 wk when microvascular disturbances are consistently present. The arterioles within the cremasteric muscle of AOD mice have a significantly (P<0.05) reduced inner diameter and vessel wall cross-sectional area. In normal animals, inner vessel diameter and vessel wall characteristics remained essentially constant from wk 22-36 of life. The average intercapillary distance in passive preparations is 20.6±0.4 μm in normal mice compared to 25.9±0.3 μm in diabetic mice; a loss of capillaries appeared to occur in diabetics but no substantial change in number of arterioles occurred. The ability of vessels to dilate from the innervated to passive state is porportionately equal to or greater than normal in the AOD mice but the actual diameters of innervated and passive arterioles are smaller than normal. The data are interpreted to indicate that an early microvascular manifestation of AOD in mice is an impairment of the vessel wall and a loss of capillaries. However, resting blood flow is only marginally decreased in the early phase of the onset of diabetes in adult mice.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine
- Cell Biology