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SummaryCX-397, a recombinant hirudin analog, is a potent and specific inhibitor of human α-thrombin. We conducted a comparative study of CX-397 and heparin in a canine model of left circumflex (LCX) coronary artery thrombosis to evaluate the anti-thrombotic efficacy of CX-397. Administration of drugs (i. v.; bolus + infusion) was commenced 10 min prior to the initiation of LCX coronary artery electrolytic injury (100 μA for 300 min). All saline-treated control animals (7/7) developed thrombotic occlusion during the experimental period, leaving a residual thrombus mass of 15.4 ± 3.8 mg. Treatment with CX-397 at three incremental dose levels reduced the incidence of occlusion (4/7, 2/5 and 0/7) and decreased thrombus weight (12.6 ± 2.5 mg, 6.3 ± 3.0 mg and 2.1 ± 1.3 mg, respectively) in a dose-dependent manner. At the in termediate dose (15,000 ATU/kg + 15,000 ATU/kg/h) or higher, CX-397 showed significant anti-thrombotic effects (p

KP-102, a synthetic growth hormone (GH)-releasing peptide, exerts a variety of effects on cardiac function. In the present study, we investigated the direct cardiac effects of KP-102 with regard to ischemia/reperfusion injury by using isolated rat hearts. Isolated Wistar rat hearts were mounted on a Langendorff apparatus and subjected to 30 min of ischemia followed by 40 min of reperfusion. The rat hearts were treated with 0.1–10 nmol/l KP-102 beginning from 15 min before ischemia until the end of the experiment, with the exception of the ischemia period. Cardiac parameters such as the left ventricular end-diastolic pressure (LVEDP), left ventricular developed pressure (LVDP), maximum dP/dt (+dP/dtmax), minimum dP/dt (−dP/dtmax), and heart rate (HR) were measured. The following ischemia/reperfusion-induced cardiac dysfunctions were observed: increased LVEDP and decreased LVDP, +dP/dtmax, and −dP/dtmax. KP-102 at a dose of 0.1 nmol/l or more induced lower LVEDP and higher LVDP and gave higher +dP/dtmax and −dP/dtmax values during the reperfusion as compared with the control groups. In particular, KP-102 at 10 nmol/l clearly suppressed the increase in the LVEDP after reperfusion; eventually, the LVEDP was restored to the preischemia level. At 40 min of reperfusion, 10 nmol/l KP-102 noticeably increased the LVDP, +dP/dtmax, and −dP/dtmax, as compared with the control. KP-102 had no effect on the HR throughout the experiment. In conclusion, KP-102 improved cardiac function in rat isolated hearts subjected to ischemia/reperfusion injury, which is independent of GH secretion.