To study the effects of drugs on level of NO and NOS in health subjects exercised at high altitude.Methods:50 health men,who
were exposed to altitude of 4 100m for 20 days,were divided into 5 groups of 10 subjects each,group 1,2,3,4 were given NO,Acetazolamide,Pholida,
Xi's capsule respecrtively andgroup 5 serves as control.The level of NO and NOS were measured at rest,before-after taking drug and exercise.Results:The changes of level of NO and NOS had not a significant difference(P>0.05) at rest,before taking drugs and after stair-exercise among 5 groups.The level of NO and NOS after exercise were
increased(P< 0.05 or 0.01) compared with that at rest,similar results in both before and after taking NO or pholida.The level of NOS was increased(P<0.05) after using Acetazolamide and xi's capsule but level of NO.The level of NOS was higher in group 1,2,3 and 4 than that in control(P<0.01 or 0.05),and level of NO was higher in group 1 and 2(P<0.05) only.Comparison between group 1 and others,the level of NO and NOS were lower in group 3 and 4(P< 0.05 or 0.01),no statistically significant in group 2.Comparison between group 2 and others,the level of NOS were lower(P<0.01) in group 3 and 4.Conclusion:The activor of NOS and level of NO in blood can be increased by four drugs above,apecially after taking NO and Pholida.The results showed that there is a better effect of NO and Pholida on altitude hypoxia.