RESUMO
<p><b>OBJECTIVE</b>To observe the effect of ultrasound stimulation at the acupoint Guanyuan (CV 4) on follicular development in menopausal rats.</p><p><b>METHODS</b>Menopausal female SD rats were selected by vaginal smear examinations. The rats were subjected to ultrasound stimulation at the acupoint Guanyuan with the output power of 0.1 W, working frequency of 9 MHz, and focal length of 4.5-5 mm. Electrochemiluminescence immunoassay was used to detect the serum estrogen levels of the menopausal rats. The changes in the ovarian tissue histology and the follicle number were observed.</p><p><b>RESULTS</b>Compared with the control group, a 10-day ultrasound stimulation for 10 and 5 min daily at Guanyuan significantly increased the serum estrogen levels and the numbers of primary and secondary follicles (P<0.05) and reduced the number of atretic follicles in the menopausal rats (P<0.05).</p><p><b>CONCLUSION</b>Ultrasound stimulation at the acupoint Guanyuan can increase the estrogen secretion function and promote the development of follicles in menopausal rats.</p>