Nitric oxide as a putative nonadrenergic noncholinergic inhibitory transmitter in the canine pylorus in vivo

Abstract

Antropyloroduodenal motility was recorded in seven anesthetized dogs to assess the role of nitric oxide and L-arginine metabolites in nonadrenergic noncholinergic (NANC) mediation of pyloric relaxation. Pyloric activity induced by duodenal field stimulation was inhibited by antral field stimulation and electrical vagal stimulation. Intra-arterial NG-L-arginine-methyl-ester (L-NAME) reduced the inhibition from antral or vagal stimulation (P less than 0.05). Intravenous infusion of L-NAME also blocked the inhibitory effect of vagal and antral stimulation but left the tetrodotoxin-insensitive action of intra-arterial vasoactive intestinal peptide (VIP) and sodium nitroprusside unchanged. L-Arginine reversed the effect of L-NAME whereas D-arginine did not. L-NAME enhanced pyloric contractions to intra-arterial acetylcholine. The NANC inhibition of the substance P-stimulated pyloric response in vitro was blocked by L-NAME and reversed by addition of L-arginine. Sodium nitroprusside was effective as a relaxant in vitro but VIP was not. These data suggest that metabolites of L-arginine mediate neural inhibition of canine pyloric motor activity.

Pharmacological Features of Non-adrenergic Non-cholinergic (NANC) Relaxation Induced by Electrical Vagal Stimulation in Isolated Mouse Stomach

“…Table 2. Effect of several autonomic drugs and NO related agents on NANC relaxations induced by EFS (5 Hz, 3.0 msec, 100 V, 10 sec trains) in the mouse whole stomach DISCUSSION Many reports have so-far concerned the role of NO in mediating NANC relaxation of isolated gastric smooth muscle in animal species such as rats (15,16), cats (23), dogs (24), guinea pigs (17)(18)(19) and ferrets (25). At present, however, no knowledge is available about the NANC inhibitory response in the mouse stomach.…”

Effects of Rikkunshi-to, a Traditional Japanese Medicine, on the Delay of Gastric Emptying Induced by NG-Nitro-L-arginine

“…NO synthase (NOS) is present in the gastrointestinal nervous system, and NO has been proposed as a non-adrenergic non-cholinergic (NANC) mediator (3). Inhibition of NO production inhibits proximal stimuli-induced pyloric relaxation and enhances distal stimuli-induced pyloric excitation in anesthetized dogs (4). In addition, intravenous administration of N G -nitro-L-arginine (L-NNA) prolongs the gastric emptying time in conscious dogs (5), and our previous study reported that the oral administration of L-NNA induced a delay in gastric emptying in rats (6,7).…”

Gastrointestinal Function Regulation by Nitrergic Efferent Nerves

“…It has been reported that metabolites of L-arginine mediate neuronal inhibition of canine pyloric motor activity in vivo (Allescher et al, 1992) and facilitate gastric emptying by inhibiting pyloric contractions (Orihata and Sarna, 1994). Gastric distension-induced pyloric relaxation appears to be mediated via a vago-vagal reflex and NO release in the rat (Ishiguchi et al, 2001).…”