Sex Difference in the Sensitivity of the Human Pancreatic Polypeptide Cell to Autonomic Nervous Stimulation in Man*

We have examined the plasma human pancreatic polypeptide (hPP) response to beta-adrenergic (infusion of epinephrine-phentolamine), vagal cholinergic, (insulin-hypoglycemia), and extravagal cholinergic (secretion infusion) stimulation in healthy, nonobese, age-matched males and females. beta-Adrenergic stimulation caused a rise in plasma hPP concentration in males that was 6 times that of females, whereas there were no differences between the sexes in the mean responses of pulse rate, systolic and diastolic blood pressure, or in plasma concentrations of glucose, insulin, and glucagon. Extravagal cholinergic stimulation caused increases of hPP secretion that were similar in males and females. Insulin-induced hypoglycemia was the most efficacious stimulus, and caused a similar rise in hPP response in males and females. Thus, in males there is greater sensitivity of the hPP cell to beta-adrenergic stimulation than females. The plasma hPP responses appear to be a more sensitive, discriminating index of adrenergic autonomic function than cardiovascular and other pancreatic hormonal responses.