Abstract
Studies were made from various angles on the epididymal adipose tissue method in which glucose uptake from the medium to the tissue is used as a parameter.Results were as follows:
1) Forty days old male rats were fed on standard diet for 5-6 weeks and when the rats were about 200-250g, they were selected for experimental use.After decapitation, laparatomy was performed and the adipose tissues attached to the both epididymides were separated by scissors.
2) The isolated adipose tissues were immediately placed in Krebs-Ringer bicarbonate buffer solution at 20°C for 30 minutes, during which period the buffer was renewed at least three times.
Meanwhile, 5-6 tissue preparations averaging 40 mg by weight were prepared from the distal portion of each sample.These preparations were pooled in a medium containing 1 mg/m/ glucose.
Then, the moisture of the tissue was lightly removed by absorption on a filter paper, after which the pieces were put in vessels containing a fixed medium.
3) The medium used was 1 ml Krebs-Ringer bicarbonate buffer (pH 7.4) containing 1 mg glucose and 0.2 mg dihydrostreptomycin.The incubation period was 4 hours at a temperature of 37°C and shaken at the rate of 120 oscillations/min.
4) After incubation, the wet tissue weight was measured by a torsion balance.
The glucose concentrations in the medium before and after incubation were measured by the glucose oxidase method.The glucose uptake by the tisuse was expressed as glucose mg/100 mg.wet weight/4 hours incubation time.
5) Construction of a dose response curve of crystalline insulin from data obtained by the aforementioned experimental method shows a distinct linear relation.Minimum insulin concentration that could be detected was 10 μU/ml and a linear relation was observed between concentrations of 10 μU/ml and 1000 μU/ml.Precision index was 0.29.
