Effects of insulin and streptozotocin-induced diabetes on brain norepinephrine metabolism in rats.
Administration of insulin (2 IU/kg, i.p.) produced a significant decrease (18%) in forebrain norepinephrine and a significant increase in the major metabolite of norepinephrine, 3-methoxy-4-hydroxyphenylglycol-sulfate (MOPEG-SO4, +19%) in rats. Streptozotocin-induced diabetes produced the opposite effects, resulting in an increase in forebrain norepinephrine (+17%) and a decrease in MOPEG-SO4 (-26%). In addition, insulin increased (+143%) and diabetes decreased (-41%) the turnover rate of norepinephrine, as measured by the rate of decrease of norepinephrine following inhibition of tyrosine hydroxylase by alpha-methyl-p-tyrosine. All of these effects in diabetic rats were reversed by insulin replacement therapy. These data are discussed within the context of mood disorders characteristic of diabetic patients.
D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D001921:Brain / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D005260:Female; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D019964:Mood Disorders / Q000097:blood; D009638:Norepinephrine / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D001786:Blood Glucose; D007328:Insulin; D009638:Norepinephrine