Comments on: "Esophageal-gastric relaxation reflex in rat: dual control of peripheral nitrergic and cholinergic transmission".
نویسندگان
چکیده
It has long been known that the esophageal distension produced by swallowing elicits a powerful proximal gastric relaxation. Gastroinhibitory control by the esophagus involves neural pathways from esophageal distension-sensitive neurons in the nucleus tractus solitarius centralis (cNTS) with connections to virtually all levels of the dorsal motor nucleus of the vagus (DMV). We have shown recently that cNTS responses are excitatory and primarily involve tyrosine hydroxylase-immunoreactive cells, whereas the DMV response involves both an alpha1 excitatory and an alpha2 inhibitory response. In the present study, using an esophageal balloon distension to evoke gastric relaxation (esophageal-gastric reflex, EGR), we investigated the peripheral pharmacological basis responsible for this reflex. Systemic administration of atropine methyl nitrate reduced the amplitude of the gastric relaxation to 52.0+/-4.4% of the original EGR, whereas NG-nitro-L-arginine methyl ester (L-NAME) reduced it to 26.3+/-7.2% of the original EGR. Concomitant administration of atropine methyl nitrate and L-NAME reduced the amplitude of the gastric relaxation to 4.0+/-2.5% of control. This reduction in the amplitude of induced EGR is quite comparable (4.3+/-2.6%) to that seen when the animal was pretreated with the nicotinic ganglionic blocker hexamethonium. In the presence of bethanechol, the amplitude of the esophageal distension-induced gastric relaxation was increased to 177.0+/-10.0% of control; administration of L-NAME reduced this amplitude to 19.9+/-9.5%. Our data provide a clear demonstration that the gastroinhibitory control by the esophagus is mediated via a dual vagal innervation consisting of inhibitory nitrergic and excitatory cholinergic transmission.
منابع مشابه
Esophageal - gastric relaxation reflex in the rat: dual control of peripheral nitrergic and cholinergic transmission
متن کامل
Esophageal-gastric relaxation reflex in rat: dual control of peripheral nitrergic and cholinergic transmission
Hermann, Gerlinda E., R. Alberto Travagli, and Richard C. Rogers. Esophageal-gastric relaxation reflex in rat: dual control of peripheral nitrergic and cholinergic transmission. Am J Physiol Regul Integr Comp Physiol 290: R1570–R1576, 2006. First published January 26, 2006; doi:10.1152/ajpregu.00717.2005.—It has long been known that the esophageal distension produced by swallowing elicits a pow...
متن کاملNoradrenergic neurons in the rat solitary nucleus participate in the esophageal-gastric relaxation reflex.
Activation of esophageal mechanosensors excites neurons in and near the central nucleus of the solitary tract (NSTc). In turn, NSTc neurons coordinate the relaxation of the stomach [i.e., the receptive relaxation reflex (RRR)] by modulating the output of vagal efferent neurons of the dorsal motor nucleus of the vagus (DMN). The NSTc area contains neurons with diverse neurochemical phenotypes, i...
متن کاملEffect of prolonged exposure to low-frequency electromagnetic fields on the interaction of nitrergic and cholinergic systems in the isolated rat trachea
Introduction: Nitric Oxide is an important endogenous compound that acts as bronchodilator in trachea. Electromagnetic fields (EMF) affect nitric oxide level in different tissues. The interaction of nitrergic and cholinergic systems in airways has been reported. Therefore, the present study was performed to evaluate the interaction of cholinergic and nitrergic systems in the trachea of rats ...
متن کاملEffect of esophagus distension on gastric blood flow, gastrin and somatostatin secretion in rat
Abstract Introduction: There are many studies about the inhibitory effect of the esophageal distention (ED) on gastric motility. Recently, it has been shown that ED decreases the gastric secretions. It is well established that the inhibitory effect of ED is mediated by activation of vago-vagal inhibitory reflex. However, there is not any investigation about the effect of the reflex on the gast...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- American journal of physiology. Regulatory, integrative and comparative physiology
دوره 290 6 شماره
صفحات -
تاریخ انتشار 2006