Adrenal glandular lipids and circulating corticosterone in severely diabetic rats

Young, adult, female Sprague-Dawley rats were fasted for 18 h and then given a single s.c. injection of alloxan (10 mg/100 g body weight) which promptly induced a severe state of diabetes. The animals were killed at frequent time intervals during the 7-day study period in order to record the dynamic changes in their capacity for adrenal steroidogenesis and secretion as measured by fluorometric determination of their circulating corticosterone (Cmpd B) levels as well as by thin layer chromatographic identification of cortical lipid moieties used for steroidogenesis. In addition to severe polydypsia, polyuria and polyphagia, these animals manifested super-normal glucose, triglycerides, free fatty acids and cholesterol in their blood, severe hepatic steatosis, adrenal hyperplasia with lipid depletion from the mineralocorticoid producing z. glomerulosa, thymus gland involution and complete degranulation of their insulin producing islet beta cells. Despite an initial high output of Cmpd B and despite progressive cortical hyperplasia, the serum Cmpd B levels became reduced and many of the animals succumbed suddenly, due most likely to inadequate adrenocortical steroidogenesis. Adrenocortical lipids showed a progressive accumulation of free fatty acids, di- and triglycerides, suggesting that some lipid enzymatic defect could be responsible for the lack of conversion of these lipid entities essential for proper steroidogenesis.