Effect of adrenalectomy on cholecystokinin-8-induced Fos-like immunoreactivity in myenteric neurons and the dorsal vagal complex in rats.

Objective: To investigate the effect of adrenalectomy on cholecystokinin-8 (CCK-8)-induced Fos-like immunoreactivity (Fos-LI) in the myenteric neurons of the dorsal vagal complex (DVC) in rats.

Animals: 16 male Sprague Dawley rats.

Procedures: Rats were allocated to 1 of 2 groups and underwent adrenalectomy or a sham adrenalectomy procedure.

Atropine methyl nitrate increases myenteric but not dorsal vagal complex Fos-like immunoreactivity in the rat.

Atropine methyl nitrate (AMN, 0.05, 0.5 and 25 mg/kg) intraperitoneally increased Fos-like immunoreactivity (Fos-LI) in the myenteric plexus, but not the dorsal vagal complex (DVC, the area postrema (AP), nucleus of the solitary tract (NTS) and the dorsal motor nucleus of the vagus (DMV)) in adult, male Sprague-Dawley rats.

Effect of sympathectomy and demedullation on increased myenteric and dorsal vagal complex Fos-like immunoreactivity by cholecystokinin-8.

Chemical sympathectomy with daily, intraperitoneal (IP) injections of guanethidine sulfate to adult rats, attenuated myenteric, but not dorsal vagal complex (DVC) Fos-like immunoreactivity (Fos-LI) by cholecystokinin-8 (CCK). This technique destroys only 60-70% of the sympathetic neurons, and spares the hormonal source of catecholamines, the adrenal medulla. The goal of the current study is to evaluate the effect of complete sympathectomy or destroying 100% of the sympathetic neurons by injecting guanethidine to 1-day-old pups (40 mg/kg daily for 5 weeks), and surgically removing the adrenal medulla.

Chemical sympathectomy attenuates myenteric but not dorsal vagal complex Fos-like immunoreactivity induced by cholecystokinin-8 in the rat.

Vagotomy and capsaicin treatment attenuate dorsal vagal complex (DVC) but not myenteric Fos-like immunoreactivity (Fos-LI) induced by cholecystokinin-8 (CCK-8). The goal of this experiment is to test the role of the sympathetic nervous system in the pathway by which CCK-8 increases myenteric Fos-LI. Adult male Sprague-Dawley rats were pretreated with guanethidine sulfate (40 mg/kg daily for 5 weeks) or vehicle intraperitoneally (IP), and injected with CCK-8 (40 microg/kg) or saline IP.