Effect of enkephalins on the function of calcium-regulating endocrine glands

Experiments on rats have shown that administration of a synthetic analog of leucine enkephalin at a dose of 100 mg/kg did not change the content of the immunoreactive parathyroid hormone in the blood plasma, but eliminated the parathyroidin-stimulating effect on the cAMP concentration in the renal tissue and AP activity in the blood. We conclude that enkephalins do not influence the secretion and metabolism of the parathyroid hormone, but block its peripheral effects and stimulate thyroid C-cell function.