Experimental endotoxemia in the rat: efficacy of prostacyclin or the prostacyclin analog iloprost.

The purpose of this study was to examine the effects of PGI2 and iloprost, a prostacyclin analog, on the sequelae of experimental endotoxic shock. Endotoxemia was produced in rats by IV injection of 20 mg/kg Salmonella enteritidis (LPS). Mean arterial blood pressure fell from 117 +/- 5 mmHg (N = 22) to 92 +/- 5 mmHg and 71 +/- 10 mmHg at 30 and 180 min post-LPS, respectively. In LPS vehicle-treated rats, blood glucose levels fell from 100 +/- 10 mg/dl to 36 +/- 8 mg/dl at 180 min. Plasma glutamate-oxaloacetate transaminase and lactate dehydrogenase (liver fraction) activities were significantly elevated above concentrations in nonshocked animals, increasing to 426 +/- 86 IU/ml and 1,019 +/- 339 IU/ml, respectively. Infusion of PGI2 or iloprost (0.5 micrograms/kg/min) did not alter the blood pressure response to LPS compared to vehicle controls. PGI2 significantly prevented the LPS-induced hypoglycemia while neither treatment significantly reduced the elevations in plasma enzymes nor prevented the lethality of LPS. Thus, the hemodynamic and biochemical indices of shock severity were not significantly improved by either prostacyclin or iloprost. It is suggested that the beneficial effects of PGI2 or prostacyclin analogs observed in other species during endotoxemia does not extend to the rat.