A study was conducted to evaluate the effect of 30-mug, 100-mug, and 300-mug 2-minute bolus doses and 2-hour infusion doses of AC137 (25,28,29 tripro-amylin, human) on plasma AC137 concentrations and plasma glucose and lactate responses in patients with insulin-dependent diabetes mellitus (IDDM). The study design was an imbedded two-way cross-over wherein patients received placebo and active boluses in one period and placebo and active infusions in the other period. Two patients in each dose group received placebo throughout the two periods. Pharmacokinetics and pharmacodynamics (PK/PD) were determined during the 6-hour period after initiation of dosing. Data were fitted with a linked PK/PD model. Pharmacokinetics were linear over the dose range studied, and attenuation of glucose and lactate responses to a mixed meal was dose and concentration dependent. The results of the PK/PD model indicate that the attenuation of glucose and lactate responses was greater after AC137 infusion doses than after the same doses given as a bolus. Glucose and lactate responses to a mixed meal were essentially negated by the 300-mug infusion dose.