Abstract: 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 ∼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.