RESUMO
<p><b>OBJECTIVE</b>To investigate the effect of preventive moxibustion at the acupoint of 'Guanyuan" (CV 4) on the stress-related hormones, proteins and genes in natural menopausal rats, and explore its protective mechanism.</p><p><b>METHODS</b>One hundred and twenty eight healthy female SD rats were used in this study, in which 16 rats aged 4 months were used as normal control group, the rest 10-month-old rats with disorder of estrus cycle were randomly divided into 7 groups, including 4 control groups at the age of 10, 12, 14 and 16 months, and 3 preventive moxibustion groups at the age of 12, 14 and 16 months, 16 cases in each group. The 10-month-old rats were treated with preventive moxibustion at the acupoint of "Guanyuan" (CV 4), twice a week for 8 weeks consistently, then observed on the following 12, 14 and 16 months. Its effects on the level of heat shock protein 70 (HSP 70), heat shock protein 70 mRNA (HSP 70 mRNA), corticotropin-releasing hormone (CRH), beta-endorphin (beta-EP), adrenocorticotrophic hormone (ACTH) in the different nuclei of hypothalamus were examined with radio-immunity, immunohistochemistry or in situ hybridization methods.</p><p><b>RESULTS</b>In the control groups, the expression of HSP 70 and HSP 70 mRNA was increased in paraventricular, arcuate and supraoptic nucleus, the level of CRH, beta-EP was showed with declining trend in volatility, while the content of ACTH was increased. In comparison to the same-aged control groups, the preventive moxibustion groups were showed that the expression of HSP 70 in the 14-month-old group was lower and the expression of HSP 70 mRNA in the 12 and 16-month-old group was significantly higher in the paraventricular nucleus (all P < 0.05), the expression of HSP 70 in the 12 and 14-month-old groups and HSP 70 mRNA in the 12-month-old group was significantly increased in the arcuate nucleus (P < 0.05, P < 0.01), while the expression of HSP 70 in the 14-month-old group and HSP 70 mRNA in the 12 and 16-month-old group was significantly decreased in the supraoptic nucleus (all P < 0.05), the content of CRH and ACTH decreased significantly in 14-month group (P < 0.05, P < 0.01), but the content of beta-EP obviously went up in the 12-month-old group (P < 0.05).</p><p><b>CONCLUSION</b>Preventive moxibustion at the acupoint of "Guanyuan" (CV 4) can regulate the expression of stress proteins, genes and hormones in the hypothalamus for the natural menopausal rats, which might be playing a protective role.</p>