MELATONIN PROTECTS RATS FROM INJURIOUS EFFECTS OF A GLUCOCORTICOID, DEXAMETHASONE

  • 1 January 1984
    • journal article
    • research article
    • Vol. 54  (6) , 255-261
Abstract
Administration of the pineal hormone melatonin (1 mg/day) to growing female rats provided significant protection against the injurious effects (decrease of body weight gain and atrophy of the thymus and adrenals) caused by a glucocorticoid, dexamethasone (0.4-0.01 mg/day). The protective effects were greater at lower doses of dexamethasone and the adrenal/body weight ratio was well maintained. Histological examination of the thymus and adrenals confirmed both the injurious effect of dexamethasone and the protective effect of melatonin. Dexamethasone also increased glutamic-pyruvic transaminase, free fatty acid, triglyceride and glucose in the serum, and melatonin significantly reduced the former 2 changes. The protection afforded by the pineal hormone melatonin against the injurious effects of dexamethasone is apparently due to a direct anti-glucocorticoidal action and does not involve any other endocrine organ.