[Houssay's phenomenon in man]

The phenomenon of clinical improvement of diabetes mellitus after occurrence of pituitary insufficiency has been reported occasionally in the medical literature, as a human counterpart of Houssay's experiment with hypophysectomized diabetic animals. We report the case of a 76-year-old woman who developed diabetes in 1928, at the age of 14, and was treated with low doses of insulin. At the age of 29, during the 7th month of her second pregnancy, she suddenly developed severe headaches and soon afterwards an intense polyuria which subsided under treatment with posterior pituitary extract. Her pregnancy followed to term but uterine stimulants had to be used at delivery because of lack of contractions. She was unable to nurse her baby and a permanent amenorrhea ensued. She continued using the posterior pituitary powder for several years, after which she discontinued it without adverse effects. The dose of insulin was decreased gradually until its replacement by chloropropamide in 1967 and glibenclamide in 1970. The present dose of glibenclamide is 2.5 mg daily, on which she has occasional mild hypoglycemic reactions. When the medication was discontinued for 5 days glycemia rose to 450 mg/dl but responded immediately to 2.5 mg of the drug with a mild hypoglycemia. She never required thyroid hormone therapy. Glucocorticoid substitution was instituted recently because of evidence of mild adrenocortical insufficiency. Basal hormone levels were normal for thyroxin, thyrotropin, FSH, LH, prolactin, hGH and cortisol; the responses to pituitary stimulation with TRH and LHRH were subnormal or nil. Cortisol stimulation with ACTH was normal. Insulin levels rose moderately after stimulation with glucagon, and with glibenclamide, with simultaneous marked decrease in glycemia.(ABSTRACT TRUNCATED AT 250 WORDS)