BACKGROUND: Previous studies have indicated preventive acupuncture and moxibustion at the Guanyuan point have positive effects on the immune system of menopausal rats.OBJECTIVE: To observe the effects of preventive acupuncture or moxibustion at the Guanyuan point on interleukin-2 (IL-2) and its receptor (IL-2R mRNA) levels in hypothalamus, serum, and uterus of menopausal rats. DESIGN: Randomized control animal experiment.SETTING: School of Acupuncture and Moxibustion, Beijing University of Chinese Medicine.MATERIALS: This study was performed at the Laboratory of Beijing University of Chinese Medicine from November 2004 to July 2005. The vaginal smear method was used to determine the estrus cycle of 9.5-month-old Sprague Dawley (SD) female rats. Three continuous estrus cycles were measured, and 160 rats with estrus cycle disorder, weighing (300 ± 20) g, were included in this study. The rats were randomly divided into four groups: preventive acupuncture group (n =48), preventive moxibustion group (n =48), model groups (n =48), and 10-month-old group (n =16). Sixteen 3.5-month-old healthy SD female rats, weighing (240 ± 20) g, were also assigned to the young group. All rats were clean grade and were purchased from the Laboratory Animal Center, Beijing University of Chinese Medicine. The experiment was in accordance with animal ethics standards.METHODS: Acupuncture was applied to the preventive acupuncture group at 10 months of age. The needle was inserted upward and perpendicularly two fen to a point that was two fen below the Guanyuan point. The rats freely moved around during needle retention (20 minutes). Acupuncture was administered twice a week and continued for eight weeks. A moxa cone (small) moxibustion was applied to the preventive moxibustion group at 10 months of age. The rats were caught gently and kept at the same position as the preventive acupuncture group. The moxa cone was ignited and held to the Guanyuan point directly. Only one moxa cone was used each time. After moxibustion, the local skin turned slightly red. Moxibustion was used twice a week and continued for eight weeks. Nothing except gently catching and lying was administered to the model group and the young group.MAIN OUTCOME MEASURES: Radioimmunoassay, in situ hybridization, and similar methods were employed to detect IL-2 in serum and the uterus, as well as IL-2R mRNA expression in the hypothalamus and uterus arcuate nuclei, of the preventive acupuncture group, preventive moxibustion group, model groups (at 12, 14, and 16 months), 10 month old group (at 10 months), and the young group (at 4 months). RESULTS: All 176 rats were included in the final analysis. ① IL-2R mRNA: IL-2R mRNA expression decreased significantly in the uterus of 12-, 14-, and 16-month-old model groups and in the hypothalamus of 14- and 16-month-old model groups (P < 0.05-0.01). Compared to the same month-aged model groups, the expression of IL-2R mRNA increased significantly in the hypothalamus and uterus of 16-month-old preventive acupuncture or moxibustion groups (P < 0.05-0.01).② IL-2: IL-2 in serum of 12- and 14-month-old model groups and in the uterus of 12-, 14-, and 16-month-old model groups decreased significantly compared to the young group (P < 0.05-0.01). IL-2 serum levels increased significantly in the 16-month-old group with preventive moxibustion; in addition, IL-2 expression levels increased significantly in the uterus of the 12-month-old group with preventive moxibustion, as well as the 12- and 16-month-old groups with preventive acupuncture (P < 0.05-0.01).CONCLUSION: As a rat ages and becomes menopausal, IL-2R mRNA expression in the hypothalamus and uterus, as well as IL-2 levels in the serum and uterus, decrease. However, preventive acupuncture and preventive moxibustion can repress the decrease to some extent. This effect is even greater in the late stages of menopause (16-month-old rats).