Effect of Ergotamine Tartrate Upon Systemic and Peripheral Blood Sugar in Rats. ∗

Summary

Under the conditions of this experiment; 2.5 mg/kg of ergotamine tartrate, intraperitoneally, had a differential effect on the peripheral and systemic blood sugar level of rats. Tail blood sugar levels were low, while blood obtained from the same animals by cardiac puncture exhibited normal glycelmic levels. This discrepancy is probably related to the prolonged vasocontrictive action of ergotamine tartrate and the resultant interference with normal peripheral circulation. It would appear that 0.2 mg/kg of epinephrine hydrochloride had little effect on the rat peripheral circulation since the hyperglycemic response in the starch-treated controls was equally distributed between systemic and peripheral blood. The results with insulin indicated that a ture hypoglycemic agent lowered both tail and heart blood sugar values to the same extent. Slight inibition of epinephrine-induced hyperglycemia by ergotamine tartrate was evident in heart blood, but appeared complete in tail blood, a dreflection no doubt of the impairment of peripheral circulation by ergotamine tartrate. These results indicate very strongly that systemic, not peripheral blood, is the better indicator of drug effects on the sugar level.