Studies of the dysglycemic peptide, pancreastatin, using a human forearm model

The physiologic effects of the chromogranin A peptide fragment, pancreastatin, were studied in six healthy Caucasian men, ages 25-46 years. Synthetic pancreastatin (human chromogranin A(273-301)-amide) was infused into the brachial artery of each subject to achieve a local concentration of approximately 200 nM over 15 minutes. Forearm blood flow was measured by strain-gauge plethysmography while (A-V)(glucose) was monitored by arterial and venous sampling. Pancreastatin infusion significantly reduced forearm glucose uptake (mean reduction +/- 1 SEM, 54 +/- 15%; P = 0.028) but did not alter forearm blood flow-indicating a metabolic, rather than hemodynamic, effect. Simultaneous infusion of pancreastatin with insulin (0.1 mU/kg/min) did not diminish insulin-induced forearm glucose uptake, suggesting pancreastatin is not simply a negative insulin modulator. The results of this study suggest that pancreastatin may contribute to the dysglycemia associated with type 2 diabetes and essential hypertension, two common human disease states in which plasma pancreastatin levels are elevated.