Effects of streptozotocin-induced diabetes on the number and diameter of fibres in different skeletal muscles of the rat.

The number and diameter of fibres in three different muscles from streptozotocin-diabetic rats were compared to the same muscles from animals of two, non-diabetic, control groups. The animals of the weight control group were fed a restricted food intake so that they grew at the same rate as the diabetic animals, whereas the other group received the stock diet ad libitum. Although body weight was the same for the diabetic and the weight control rats, the muscles weighed less in the diabetic animals. This was reflected in trends to fibres with smaller diameters and to lower fibre number in the diabetic animals. These differences between diabetic and control animals became more significant when the number and diameter of fibres were used to calculate total cross sectional area. There was no damage to the fibres when examined under the light microscope. It is concluded that streptozotocin-diabetes has an adverse effect on the number and diameter of fibres in skeletal muscles.