Subdiaphragmatic vagotomy enhances stress-induced epinephrine release in rats.
Neuroendocrine stress response is regulated by several feedback loops. Since it has been suggested that afferent vagal pathways contribute to these feedback loops, we examined the effect of surgical subdiaphragmatic vagotomy on both baseline and stress-induced increases in plasma epinephrine, norepinephrine, and corticosterone levels in vagotomized and sham-operated Sprague Dawley rats. On either the 3rd or 14th day following vagotomy, the animals were exposed to acute immobilization stress and blood from the jugular vein was collected both before and during stress exposure. We found that vagotomy significantly enhanced immobilization-induced increases of plasma epinephrine, norepinephrine, and corticosterone levels on the 3rd day following surgery. However, on the 14th day following surgery, vagotomy enhanced only increase of plasma epinephrine levels in stressed rats. Our data indicate that afferent pathways of the vagus nerve are involved in negative feedback regulation of epinephrine secretion from the adrenal medulla during stressful conditions. We hypothesize that this feedback mechanism might be mediated by the binding of circulating epinephrine on β2-adrenergic receptors localized on sensory endings of the vagus nerve.
Institute of Physiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia; Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia.
Boris
B
Mravec
Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia; Institute of Pathophysiology, Faculty of Medicine, Comenius University, Bratislava, Slovakia.
Katarina
K
Ondicova
Institute of Experimental Endocrinology, Slovak Academy of Sciences, Bratislava, Slovakia.
Andrej
A
Tillinger
Clinic of Psychiatry, Faculty of Medicine, Comenius University and University Hospital, Bratislava, Slovakia. Electronic address: jan.pecenak@sm.unb.sk.
Jan
J
Pecenak
D000818:Animals; D001835:Body Weight / Q000502:physiology; D003345:Corticosterone / Q000097:blood; D004837:Epinephrine / Q000097:blood*; D025461:Feedback, Physiological; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology; D008297:Male; D009638:Norepinephrine / Q000097:blood; D010913:Pituitary-Adrenal System / Q000503:physiopathology; D011897:Random Allocation; D017207:Rats, Sprague-Dawley; D012149:Restraint, Physical; D013315:Stress, Psychological / Q000503:physiopathology*; D013997:Time Factors; D014628:Vagotomy / Q000379:methods; D014630:Vagus Nerve / Q000503:physiopathology*
D003345:Corticosterone; D009638:Norepinephrine; D004837:Epinephrine
Corticosterone; Epinephrine; Immobilization; Norepinephrine; Rats; Vagotomy