[Preventive effect of quinacrine on the development of heat injury by stabilizing membrane phospholipids metabolism and beta-adrenoceptor].

Previous studies have demonstrated that the activation of phospholipase A2 (PLA2) during heat stress would caused disorder of membrane phospholipids metabolism, accompanied by a decrease in phosphatidylcholine and phosphatidyl-serine and an increase in arachidonic acid. In heat stressed rats, a down-regulation of beta-adrenergic receptor in lung tissue was observed due to activation of PLA2. In the present work, it was demonstrated that pretreatment of rats with PLA2 inhibitor, quinacrine (20 mg/kg, I.P.), 1 h before heat stress could block these membrane lipid alterations, and the tolerance of rats to heat exposure was enhanced. The effect of quinacrine on the thermotolerance of marching soldiers with 15 kg of load under hot environment was also investigated. The results indicated that in the soldiers taken orally 200 mg quinacrine 1 h before marching, their heart rate, body temperature, accumulation of blood lactic acid and the changes of index of heart function were significantly improved as compared to the control group at the end of 3 h marching. According to these data, it can be concluded that quinacrine is a useful drug to prevent derangement of beta-adrenoceptor and membrane phospholipids metabolism in the development of heat stress. So as to prevent heat injury, and to improve tolerance to heat stress.