Heparin pretreatment suppresses norepinephrine concentrations in dogs in endotoxic shock.

Mongrel dogs were treated intravenously with either 1000 units of beef-lung heparin per kilogram of body weight or with isotonic saline, before intravenous administration of E. coli endotoxin. We found significant differences in circulating norepinephrine concentrations between a heparin-pretreatment group (1.89 +/- 0.39 microgram/liter) and the control group (9.83 +/- 4.64 microgram/liter), but none with respect to epinephrine. Systolic blood pressures at 360 min were also significantly (P less than 0.05) different, 148 +/- 6 mmHg as compared with 118 +/- 13.4 mmHg. Evidently heparin pretreatment can decrease circulating norepinephrine concentrations in the endotoxic state and changes in circulating catecholamine concentrations can affect physiological variables.