In Vivo: TPN729 (1.25, 2.5 and 5.0 mg/kg; intraduodenal injection, once) increases intracavernous pressure/blood pressure (ICP/BP) with the dose of 5.0 mg/kg at all time points and with the dose of 2.5 mg/kg at 75, 90, 105, and 120 minutes time points.TPN729 (5.0 μg/kg; i.v., once) significantly increases ICP and ICP/BP of male Beagle dogs.