Alterations induced by alloxan-diabetes and starvation on functional activity of the rat portal vein perfused in vitro.
The levels of isometric developed tension (IDT) in portal veins from starved and diabetic rats in glucose medium were of the same magnitude but significantly reduced compared with veins from normal rats. Glucose removal led to contractile depression, more marked in starved veins (-74%; p < 0.001 vs. diabetics and normals). Addition of glucose, pyruvate, acetate, lactate, or butyrate counteracted this depression in all groups but in diabetics butyrate significantly stimulated IDT over controls whereas in starved veins lactate overcame IDT reduction only partially. Added insulin significantly enhanced contractile recovery with glucose in normal and diabetic preparations but was ineffective in starved veins. Glycogen content was significantly lower in diabetics; however, in no group did changes occur in incubated veins as compared with unincubated ones. Glycerol production was significantly higher in diabetic veins. It would appear that, although experimental diabetes induces a shift to fatty acid utilization, aerobic glycolysis and mitochondrial respiration are somehow preserved as reflected by the IDT recovery with pyruvate or lactate.
D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000503:physiopathology*; D011169:Portal Vein / Q000378:metabolism / Q000503:physiopathology; D051381:Rats; D013217:Starvation / Q000503:physiopathology*
D006003:Glycogen; D005947:Glucose; D005990:Glycerol