Studies on carbohydrates in reptiles

Summary

• 1. The effect of applying light insulin doses of 0.03 U and heavy insulin doses of 0.1 U/gm body weight on the glucose of blood and glycogen content of tissues of Uromastyx was investigated.

• 2. An initial phase of hypoglycemia was found to occur soon after the administration of light and heavy insulin doses, at temperatures ranging from 20° to 40°c. This phase is interrupted by an obvious hyperglycemia to be followed again by hypoglycemia. At 45°c however, the hyperglycemia occurs at once after insulin injections, to be followed by hypoglycemia.

• 3. The final hypoglycemia differs in both intensity and duration according to the dose given as well as the temperature of experimental animal. Rise in temperature shortens the time of onset of final hypoglycemia. Along the temperature range from 20° to 40°c a temperature coefficient of about 1.7 was recorded.

• 4. Typical insulin convulsions appear not to take place in Uromastyx even after heavy insulin doses of 0.10 U/gm body weight and at comparatively high temperatures (45°c).

• 5. After the administration of insulin (0.03 U/gm body weight at 30°c), a general decrease in glycogen content was observed in the tissues of the brain, lung, heart, liver, skeletal muscles, plain muscles, gonads and kidneys. This runs in harmony with our earlier finding (1959) that in depancreatised animals a general increase in glycogen content of nearly all the tissues was recorded.