EFFECT OF ADRENAL CORTEX EXTRACT UPON THE TOLERANCE OF THE EVISCERATED RAT FOR INTRAVENOUSLY ADMINISTERED GLUCOSE

Abstract

A collateral circulation was induced in male rats (185-205 gs.) of the Sprague-Dawley strain by ligation of the inferior vena cava. At a wt. of 250 [plus or minus] 2 gs., the animals were anesthetized (cyclopal), and all of the intra-abdominal organs were removed except the kidneys and adrenals. Infusions into the saphenous vein were made by continuous injn. machines which delivered fluid at a rate of 20 ml. in 24 hrs./ rat. The change in the level of blood glucose during the subsequent 24 hrs. was the index of glucose tolerance. In expt. 1, 22 pairs of eviscerated rats were infused with glucose (18/100/h) without insulin, and 21 pairs were infused with glucose (72/100/h) plus insulin for periods of 2 and 4 hrs. The admn. of adrenal cortex extract in large amts. to one rat of each pair had no significant effect upon the level of blood glucose within 4 hrs. of infusion. In expt. 2, the tolerance to glucose was detd. over a 24-hr. period. Eviscerated rats were given glucose loads of 4, 6, 8 and 10/100/h. Twenty-22 pairs of rats were tested at each of the 4 levels. Similar animals were given insulin with glucose loads of 30, 32, 34, 38 and 40/100/h. Eleven to 12 pairs of rats were tested at each level. Adrenal cortex extract administered to rats given insulin caused a significant rise in blood glucose above control values but had only a questionable effect in animals not given insulin.