title: Soy isoflavone affects the autonomic nervous system in a tissue-specific manner in anesthetized rats.
abstract: We examined and compared the effects of taste stimulation by soy saponin as well as soy isoflavone and intragastric (IG) injection of both on the autonomic nerve activities and feeding behavior in rats. We found that taste stimulation by soy saponin or soy isoflavone-rich solution (SIRS) did not affect the activity of the sympathetic nerve supplying the adrenal gland in urethane-anesthetized rats; however, IG injection of SIRS, but not soy saponin, stimulated the adrenal sympathetic nerve activity (ASNA) in a dose-dependent manner. Moreover, IG injection of SIRS significantly suppressed the activity of the vagus nerve innervating the stomach, whereas sympathetic nerve outflows to brown or white adipose tissue were not affected by IG injection of SIRS. To test the involvement of the afferent autonomic nerve in the abdominal organs for regulation of the efferent ASNA by SIRS, we examined the response of the adrenal sympathetic innervation to SIRS injection in rats with ablated afferent vagus or afferent sympathetic nerves. The activating effect of SIRS on the ASNA was inhibited in sympathectomized rats but not in vagotomized rats. Thus, our data suggest that soy isoflavone might affect tissue-specific autonomic nerves through the afferent sympathetic nerve pathway.
authors.affiliation: Department of Physiology II, Kanazawa Medical University, Uchinada Ishikawa 920-0293, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Tanida
authors.forename: Kazuki
authors.initials: K
authors.lastname: Imanishi
authors.forename: Mie
authors.initials: M
authors.lastname: Komatsu
authors.forename: Jun
authors.initials: J
authors.lastname: Satomi
authors.forename: Naoki
authors.initials: N
authors.lastname: Yamamoto
authors.forename: Mofei
authors.initials: M
authors.lastname: Wang
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Kurata
authors.forename: Toshishige
authors.initials: T
authors.lastname: Shibamoto
mesh_terms: D000818:Animals; D001341:Autonomic Nervous System / Q000187:drug effects*; D001835:Body Weight; D005247:Feeding Behavior; D007529:Isoflavones / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012503:Saponins / Q000494:pharmacology*; D013025:Glycine max / Q000737:chemistry*; D013268:Stimulation, Chemical; D013270:Stomach / Q000294:innervation; D013564:Sympathetic Nervous System / Q000187:drug effects
chemical_list: D007529:Isoflavones; D012503:Saponins
keywords: Isoflavone; abdominal adipose tissue; adrenal gland; autonomic nerve; obesity; stomach