Abstract
In male rats, activity in subdiaphragmatic vagal afferents modulates nociception via an adrenal medulla–dependent mechanism. Because both the vagus and adrenal medullae are sexually dimorphic, we evaluated vagotomy-induced changes in mechanical nociceptive threshold and inflammatory hyperalgesia in female rats and compared them to those previously reported in male rats. We have found that (1) mechanical nociceptive threshold is lower in female rats than in male rats, perhaps because of tonic release of adrenal medullary factors in female rats; (2) mechanical nociceptive threshold in female rats is influenced to a lesser degree by activity in the subdiaphragmatic vagus; (3) vagotomy-induced enhancement of bradykinin hyperalgesia is greater in female rats; (4) in female rats, in contrast to male rats, celiac plus celiac accessory branch vagotomy failed to fully account for the enhancement of bradykinin hyperalgesia in complete subdiaphragmatic vagotomy; and (5) in female rats, in contrast to male rats, adrenal medullectomy plus subdiaphragmatic vagotomy only partially (∼30%) reversed the effect of vagotomy on bradykinin hyperalgesia. These findings demonstrate sexual dimorphism in the modulation of both mechanical nociceptive threshold and bradykinin-induced hyperalgesia by activity in subdiaphragmatic vagal afferents as well as the adrenal medulla.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
