정상 및 Alloxan당뇨병 흰쥐의 간절편에 있어서 C14-포도당 산화대사에 관한 실험

Abstract

Liver slices of 18 normal and 12 alloxan diabetic rats (Sprague'Dawley) were incubated with incubation mixture consisting of 15 cc of phosphate buffer to which were added Cl4·labeled glucose and 15 cc of oxygen. Incubation was continued up to 7 or 8 hours. During the long incubation period the incubation media and gas phases were replaced with fresh media and oxygen at hourly intervals. This procedure made it possible to obtain hourly samples to determine the amount and specific activity of C02 produced by the liver slices during the experimental period. It also had the advantage of presenting the tissue with a substrate of essentially constant concentration and specific activity of medium glucose. Data were summarized as the following. l) Glucose disappearance from medium glucose rose during the first 4 hours and remained approximately constant, thereafter showing maximum values of 61.1 ,uM/hr/gm in the alloxan diabetic liver. Glucose disappearance rate decreased to one tenth of normal value in the alloxan diabetic liver slices. 2) Total C02 production rate was initially high, then fell rapidly and, after 3~4 hours it showed a steady values during the period of experiment. These steady values were taken for comparison between control and alloxan diabetic rats. In the diabetic cases total C02 production rate was about one sixth of normal control. 3) The rate of C02 production derived from medium C14-glucose:which is calculated by multiplying total C02 production rate with relative specifie activity (RSA) , was 61.5,uM/hr/gm in the control and 0.22 uM/hr/gm in the diabetic liver slices. 4) Fractions of glucose disappeared into respiratory C02, which is named relative glucose disappearance, were calculated and found to be 16.9% in the control and 0.65% in the diabetic liver slices.