DIABETIC TRAITS IN A STRAIN OF RATS1

Abstract

A a result of an investigation of the effects of drugs on the carbohydrate metabolism of rats, control glucose tolerance tests revealed that pedigreed, sexually mature, male rats of the Yale strain2 exhibited a significantly lower glucose tolerance than rats of the Wistar strain of corresponding age and sex, grown under the same conditions and maintained on the same diet. In view of the extensive use of rats in carbohydrate studies, considerable importance is attached to the questions, a), Which strain has a ‘normal’ carbohydrate tolerance? b), What criteria justify the designation ‘normal’ carbohydrate tolerance in the rat? Relative to these questions, the data here reported cover a period of 22 months and consist of 425 glucose tolerance tests on 240 rats, normal with respect to weight gains and general physical appearance. The age of the animals ranged from 22 days to 14 months. No animal had received drugs at any time except the 22 Wistar rats shown in table 2. These animals received small doses of physostigmine or strychnine 10 to 14 days prior to the tolerance tests, but the tests were not affected by the drugs. Glucose was administered by stomach tube or by intraperitoneal injection.