[Beneficial effect of thyrotropin-releasing hormone in combination with HSD on hemorrhagic shock with pulmonary edema at high altitude in the rat].

OBJECTIVE

To study the effects of thyrotropin-releasing hormone (TRH) in combination with hypertonic saline/dextran (7.5% NaCl + 6% Dextran 40, HSD ) on hemorrhagic shock with pulmonary edema in the rats which were recently brought to high altitude.

METHODS

Forty-nine SD rats, transported to Lasa, Tibet, which was 3,760 meters above the sea level, were anesthetized one week later with sodium pentobarbital (30 mg/kg, intraperitoneal). Hemorrhagic shock with pulmonary edema was induced by hemorrhage (50 mm Hg maintained for 1 hour,1 mm Hg=0.133 kPa) plus intravenous injection of oleic acid (50 microl/kg). They were equally divided into seven groups (n=7): normal control, hemorrhagic shock, hemorrhagic shock with pulmonary edema (HSPE), HSPE plus TRH (5 mg/kg), HSPE plus HSD (4 ml/kg), and HEPE plus TRH and HSD in combination. Hemodynamic parameters including mean arterial blood pressure(MAP), left intraventricular systolic pressure (LVSP) and the maximal change rate of intraventricular pressure rise or decline (+/- dp/dt max) were observed at 15, 30, 60 and 120 minutes, blood gases were analyzed at 30 and 120 minutes, and the water content of lung and brain was determined at 120 minutes after drug administration.

RESULTS

TRH or HSD used alone or in combination significantly increased MAP, LVSP and +/- dp/dt max (P<0.05 or P<0.01 ), ameliorated acid-base imbalance, and decreased the water content of lung and brain. The effect of the two in combination was superior to either drug used alone.

CONCLUSIONS

TRH in combination with HSD can be used in the treatment of hemorrhagic shock with pulmonary edema at high altitude.