Effect of alloxan-diabetes on the metabolism of rabbit colon smooth muscle.

The metabolism of colon smooth muscle from normal and alloxan-diabetic rabbits was studied in vitro. Glucose uptake, incorporation of glucose minus14-C into glycogen and incorporation of leucine minus-14C into protein were determined. These three parameters were all depressed in diabetic smooth muscle incubated in a medium containing 5.6 mM glucose. Raising the glucose concentration in the medium to 22.2 mM almost doubled the glucose uptake both in diabetic and normal smooth muscle and at this glucose concentration no significant difference in this parameter was found. Insulin (0.1 U/ml) added in vitro stimulated glucose uptake, incorporation of glucose minus14-C into glycogen and incorporation of leucine minus14-C into protein in diabetic colon smooth muscle. Insulin stimulated glucose uptake to the same degree in normal and diabetic colon smooth muscle, while its effect on glucose minus14-C and leucine minus14-C incorporation tended to be somewhat more pronounced in diabetic colon muscle.