Objective    To study the effects of Yangjing Zhongzi decoction (YJZZ) on the apoptosis of spermatogenic cells in male rats after hypoxic injury.     Methods    The total of 36 Sprague-Dawley(SD) male rats were randomly divided into normal group

hypoxic group

high-dose YJZZ group and low-dose YJZZ group. The rats of the later 3 groups lived for 4 weeks in a hypobaric chamber simulating 5 000 m altitude. Besides fed with standard chow

the rats of high-dose and low-dose YJZZ groups were given the decoction intragastrically at a dose of 35 and 10 g·kg

-1

·d

-1

res

pectively for 4 weeks. Then the rats were sacrificed and their testis were resected for light microscopic and electron microscopic studies. The apoptosis of spermatogenic cells were detected with terminal deoxynucleotidyl transferase-mediated dUDP-nick end labeling (TUNEL) method.     Results    Compared with normal control

the testes in the hypoxic group had germ cells in a disordered arrangement

decreased spermatogenic cells and sperms in the seminiferous tubules

and thinned seminiferous epithelium. While the large-dose YJZZ group did not show such morphological features. In the hypoxic group

electron microscopy observed obvious apoptosis in spermatogenic cells

but no apoptosis was seen in the large-dose YJZZ group. The percentage of positive TUNEL cells in the hypoxic group was significantly higher than those in the other groups (

P

<

0.01).     Conclusion    YJZZ decoction can reduce the apoptosis in spermatogenic cells and increase the number of spermatogenic cells.