Electrical and manual acupuncture stimulation affects estrous cyclicity and neuroendocrine function in a DHT-induced rat polycystic ovary syndrome model
Yi Feng, Julia Johansson, Ruijin Shao, Louise Mannerås Holm, Håkan Billig, Elisabet Stener-Victorin
Both low-frequency electro-acupuncture (EA) and manual acupuncture improve menstrual frequency and decrease circulating androgens in women with polycystic ovary syndrome (PCOS). We sought to determine whether low-frequency EA is more effective than manual stimulation in regulating disturbed estrous cyclicity in rats with PCOS induced by 5?-dihydrotestosterone (DHT). To identify the central mechanisms of the effects of stimulation, we assessed hypothalamic mRNA expression of molecules that regulate reproductive and neuroendocrine function.
From age 70 days, rats received 2-Hz EA or manual stimulation of the needles five times/week for 4–5 weeks; untreated rats served as controls. Specific hypothalamic nuclei were obtained by laser microdissection, and mRNA expression was measured with TaqMan low-density arrays. Untreated rats were acyclic. During the last 2 weeks of treatment, seven of eight (88%) rats in the EA group had epithelial keratinocytes, demonstrating estrous cycle change (p= 0.034 vs. controls). In the manual group, five of eight (62%) rats had estrous cycle changes (ns vs. controls). mRNA expression of the opioid receptors Oprk1 and Oprm1 in the hypothalamic arcuate nucleus was lower in the EA group than in untreated controls. mRNA expression of the steroid hormone receptors Esr2, Pgr, and Kiss1r was lower in the manual group than in the controls.
In rats with DHT-induced PCOS, low-frequency EA restored disturbed estrous cyclicity but did not differ from manual stimulation group, although electrical stimulation lowered serum testosterone in responders, those with restored estrus cyclicity, and differed from both controls and the manual stimulation group. Thus, EA cannot in all aspects be considered superior to manual stimulation.
The effects of low-frequency EA may be mediated by central opioid receptors, while manual stimulation may involve regulation of steroid hormone/peptide receptors.