Abstract
In the previous investigation of the author, increased renal gluconeogenesis in diabetie was observed as a result of studies on eviscerated rats with kidney. In present report, effect of insulin on renal gluconeogenesis in alloxan diabetic rats were studied.
Method: 14C-lactate was injected intrayenouly to eviscerated diabetic rats with kidney and blood samples were withdrawn at the end of 30 min and 60 min after 14C-lactate injection. Incorporation of 14C from 14C-lactate into glucose was measured by glucosazon formation of each sample. Insulin (0.05u, 0.2u, 0.5u) was injected simultaneously with 14C-lactate and the rate of incorporation of 14C into blood glucose was compared with that of the control. Blood glucose was analysed by means of 14C-glucose in order to ascertained glucose entry and effect of insulin on the glucose entry in eviscerated diabetic animals was investigated.
Results: The effect of insulin in dose of 0.05u on incorporation of 14C from 14C-lactate into blood glucose in eviscerated alloxan diabetic rats was not observed. Insulin in dose of 0.2u did not affect the incorporation of 14C from 14C-lactate into blood glucose in eviscerated alloxan diabetic rats whose blood sugar levels were higher than 200mg/dl, but it suppressed the incorporation of 14C from 14C-lactate into blood glucose in rats whose blood sugar levels were lower than 200mg/dl. With the administration of insulin in dose of 0.5 u, the incorporation of 14C from 14C-lactate into blood glucose and blood glucose entry were definitely suppressed.
It is suggested that insulin directly affects the glucose metabolism in kidney and suppresses the increased renal gluconeogenesis in diabetic animals.
