Insulin and Hypothalamo-Pituitary Adrenal System

Abstract

Insulin given exogeneously changes the hormone balance in which hypothalamo pituitary adrenal system plays an important role and these changes are reflected in the fluctuations of the several components of body fluids. As, among these, the pattern of ciaculating eosinophil leucocytes count considerably relates with function of hypothalamo-pituitary adrenal system, I attempted a test method for this system, using eosinophil count as an indicator after subcutaneous injection of insulin 0.15 unit per Kg. Body weight in fasting state, and investigated the responses in various neuro-endocrine disorders.
In healthy controls, 50 per cent decrease of eosinophils occurred 4 hours after injection of insulin.
By the prevention of hypoglycemia with glucose administration, eosinopenia was not induced in healthy controls. Adrenolytic agent and hypnotica (Isomital) change the pattern of eosinopenia. Therefore, the response is primarily conditioned by the hypoglycemia and is related with neural factors.
Abnormal responses of eosinophils were found in all cases of adrenocortical insufficiency. This finding suggests that the insulin eosinopenia occurrs with intact adrenal cortex.
In spite of absence of adrenal insufficiency, acromegalic patients also showed abnormal response. This observation indicates the interference of pituitary other than adrenal cortex.
Diabetes mellitus, diabetes insipidus, hyperthyroidism and obesity showed abnormal responses.
In conclusion, abnormal patterns of insulin eosinopenia indicate the dearrangement of the activity of hypothalamo-pituitary adrenal system, and would render means of interpretating the pathologic physiology of the diseases.