[Studies on the association of angiotensinogen polymorphisms and hypoxia acclimatization].

Objective: To research the effects of gene polymorphisms of AGT at G-217A and T174M loci on incidence and the hypoxia acclimation to acute mountain sickness (AMS).

Methods: Step 1:61 Han students origin low landers were exposed in acute hypoxia at 4 800 m altitude-equivalent for 6 hours, and took the supine bicycle exercise for 20 min at quantitative load of 60 r/min, 80 W after entering the cabin for 30 min, then the AMS were evaluated by the Lake Louise acute mountain sickness scoring system (LLS). The physical index of heart rate (HR), ambulatory blood pressure and oxygen saturation (SpO) were measured during exercise. Step 2:The physical index was measured again in acute hypoxic exposure after 3 weeks increasing hypoxia exercise (At an increasing altitude of 2 500 m, 3 500 m, 4 800 m, time of 2 hours/day, 4 days/week, and in moderate intensity of exercise). PCR-RFLP was used to determine the genotypes and alleles frequencies of AGT at G-217A and T174M loci.

Results: In step 1 the hypoxic exposure, for the G-217A locus in AGT, there was no significant difference between GG and GA+AA gene tester. While in step 2 the hypoxic exposure, the SpO of GG gene was lower than GA+AA gene obviously (<0.05). No significant differences of AMS incidence, VE, SpO, HR and blood pressure were detected in different genotypes and alleles at T174M locusin both hypoxic exposures.

Conclusions: The G-217A may be the genetics sign of hypoxia acclimation. There is no obvious rel-evancy between the T174M polymorphism and the occurrence of AMS/hypoxia acclimation.