Factors Influencing the Urinary Excretion of 3′,5′-Adenosine Monophosphate in Humans

Abstract

The 24-hr urinary excretion of cyclic 3′5′-adenosine monophosphate (cyclic AMP) in 21 control subjects (3544 ± 175 nmoles, mean ±sem) was contrasted with the cyclic AMP excretion in patients with hyperparathyroidism (5719 ± 1200 nmoles, p <.01), hypoparathyroidism (1943 ±312 nmoles, p <.001), renal disease (596 ±208 nmoles, p <.001), and women during the menstrual cycle and pregnancy. An effect of parathyroid hormone on the urinary excretion of cyclic AMP was implied from: 1) the increased urinary excretion of the nucleotide in patients with hyperparathyroidism and the low excretion in patients with hypoparathyroidism, and 2) the acute reduction to normal in urine cyclic AMP following removal of a parathyroid adenoma. An effect of steroid and/or pituitary or placental hormones on the urinary excretion of cyclic AMP was suggested from observing a midcycle peak in nucleotide excretion during ovulatory menstrual cycles, and a progressive increase in urinary excretion of the nucleotide during pregnancy. In addition, acute increments in urinary excretion rates of cyclic AMP in response to injections or infusions of parathyroid extract, glucagon and vasopressin were demonstrated. Acute infusions of human GH had no effect on cyclic AMP excretion. The marked variation in the magnitude of the acute responses and the variations in 24-hr cyclic AMP excretion in different patient groups suggested that many different factors must be considered in evaluating the 24-hr urinary content of the nucleotide. Among those considered were: 1) those factor(s) which influence the escape of the nucleotide from cell membranes, 2) the renal or extrarenal origin of the nucleotide, and 3) the functional status of the kidneys.