Effects of simulated microgravity on sex hormones of male rats and intervention with traditional Chinese medicine

GUO Yanbing; PAN Qiuxia; LI Jie; CHEN Xue; ZHANG Bo

doi:10.16289/j.cnki.1002-0837.2026.01013

Abstract：Objective To observe the effects of microgravity environment on sex hormones in sexually mature male rats and the intervention effect of traditional Chinese medicine(TCM),with the purpose of providing a data reference for research on astronauts'reproductive health.Methods 48 healthy sexually mature male SD rats were randomly divided into the control group,experimental group,Yin-nourishing group and Yang-warming group.Except for the control group,rats in the other three groups underwent tail suspension for 28 days to simulate microgravity.The Yin-nourishing and Yang-warming groups received daily oral administration of corresponding TCM decoctions for 28 days,while the experimental group received an equal volume of normal saline.Testicular mass was recorded,histopathological changes in testicular tissue were assessed by hematoxylin and eosin(HE)staining,and serum levels of sex hormones were measured using enzyme-linked immunosorbent assay(ELISA).Results Compared with the control group,testicular mass was significantly reduced in the experimental,Yin-nourishing and Yang-warming groups after 4 weeks of suspension(all P<0.01).Compared with the experimental group,testicular mass showed a tendency to increase in Yin-nourishing and Yang-warming groups,but the differences were not statistically significant(all P>0.05).HE staining revealed normal testicular architecture in the control group,while marked or severe atrophy were observed in the experimental group.Both the Yin-nourishing group and Yang-warming group showed varying degrees of structural damage,yet less severe than those in the experimental group.Serum levels of luteinizing hormone(LH),prostaglandin E(PGE),and gonadotropin-releasing hormone(GnRH)in the experimental group showed a downward trend compared with the control group,but without statistical significance(all P>0.05).Compared with the experimental group,the Yin-nourishing group showed significantly increased serum levels of LH and testosterone(all P<0.01),significantly decreased follicle-stimulating hormone(FSH)(P<0.05),and a non-significant trend toward reduced PGE and GnRH(all P>0.05).The Yang-warming group showed a significant increase in LH levels compared with the experimental group(P<0.01),while no significant differences were found in GnRH,testosterone,PGE and FSH levels(all P>0.05).Conclusion Although Yin-nourishing and Yang-warming TCM interventions did not significantly reverse testicular atrophy induced by simulated microgravity,they can mitigated the extent of histopathological damage.Yin-nourishing TCM may alleviate such reproductive injury by modulating the expression of sex hormones.