Nitric oxide producing neurons in the monkey and human digestive system

Abstract

Nitric oxide has been proposed as an inhibitory transmitter molecule that plays a role in muscle relaxation and vasodilation in the gastrointestinal tract. The present study analyzes the distribution of nitric-oxide-producing neurons in the monkey and human digestive system by means of nicotinamide-adenine-dinucleotide-phosphate-diaphorase histochemistry. This histochemical method is reliable and convenient for the visualization of neuronal nitric-oxide synthase, the enzyme responsible for nitric-oxide generation. In the gastrointestinal tract, nitric-oxide-synthase-related diaphorase activity was present in nerve fibers running throughout the muscular layer (circular > longitudinal) and in numerous ganglion cells and processes in the myenteric plexus of monkeys and humans. Labelled ganglion cells and fibers also were observed in the submucous plexus, although they were much less numerous than those seen in the myenteric plexus. In the submucosa, a few positive fibers were seen around blood vessels. In the mucosa, stained fibers were sparse at the base of the villi and crypts, whereas they were quite abundant in the muscularis mucosae, especially in the small intestine and colon. In the gallbladder (human), labelling was found in ganglion cells and processes of the innermost and outermost ganglionated plexuses. Stained fibers also were distributed to the muscular layer and, less abundantly, to the mucosa and vasculature. Labelled fibers were more abundant in the sphincter of Oddi (human) than in the gallbladder. In the monkey and human pancreas, nicotinamide-adenine-dinucleotide-diaphorase staining was seen mainly in ganglion cells and fibers of intrapancreatic ganglia, and in processes running among acini, around ducts and in the stroma. A moderate density of stained fibers also was distributed to the vasculature, whereas the islets showed few positive processes. Finally, double label experiments performed in the pancreas showed that the vast majority of neurons producing nitric oxide are immunoreactive for vasoactive intestinal peptide.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative changes of nitrergic neurons during postnatal development of chicken myenteric plexus

“…These changes are similar to those previously reported in chicken embryos (Balaskas et al, 1995;Bagyanszki et al, 2000;O′Donnell et al, 2006), and other species like guinea pigs (Nichols et al, 1992), rabbits (Junquera et al, 1998), rats (Cracco and Filogamo, 1994), pigs (Sri Paran et al, 2009), and monkeys and humans (Degiorgio et al, 1994;Román et al, 2004).…”

“…Dawson et al (1991) has previously reported that NOS staining is identical to NADPH-d staining. NADPH-d staining has been used in recent studies to qualify and quantify nitrergic neurons in the gut in different species: mice (Azzena and Mancinelli, 1999), rats (Sandgren et al, 2003), guinea-pigs (Wade et al, 2003), sheep (Lalatta-Costerbosa et al, 2007), rabbits (Junquera et al, 1998), dogs (Ward et al, 1992), pigs (Cserni et al, 2009b), cats (Feher and Montagnese, 1994), monkeys and humans (Degiorgio et al, 1994;Wittmeyer et al, 2010), pigs, guinea-pigs, and rats (Bodi et al, 2009), andchicks (O′Donnell et al, 2006). The whole-mount preparation technique allows the observation of the 3D meshwork of the myenteric plexus and quantitative and qualitative analyses of the myenteric neurons (Wester et al, 1999).…”

Peptidergic hormones and neuropeptides, and aminergic neurotransmitters of the pancreatic islets of the Houbara bustard (Chlamydotis undulata)

“…In the islets, as in other parts of the digestive system of the Houbara bustard (Mensah-Brown, unpublished observations), nNOS is colocalised with somatostatin and not with VIP as observed in the digestive systems of humans and monkeys (De Giorgio et al 1994).…”

Gastrointestinal Function Regulation by Nitrergic Efferent Nerves

“…The presence of NOS has also been demonstrated in the gall bladder and biliary pathways of the guinea pig (Grozdanovic et al, 1994), monkey, and human (De Giorgio et al, 1994;Uemura et al, 1997). In humans, NOS-containing nerve fibers are more abundant in the sphincter of Oddi than in the gall bladder (De Giorgio et al, 1994). In anesthetized cats, L-NA increased the flow resistance exerted by the sphincter of Oddi, but did not alter gall bladder motility, suggesting that nitrergic tonic inhibition is, if any, minimal in the gall bladder (Thune et al, 1995).…”

“…Recombinant human hemoglobin may alter the motor function of the sphincter of Oddi in vitro and in vivo by binding endogenous NO (Cullen et al, 1996). Neurons containing nNOS immunoreactivity or NADPH diaphorase were histochemically detected in the sphincter of Oddi of the human, monkey (De Giorgio et al, 1994), dog (Tanobe et al, 1995), guinea pig (Wells et al, 1995), and possum (Baker et al, 1993;Simula et al, 2001). The presence of NOS has also been demonstrated in the gall bladder and biliary pathways of the guinea pig (Grozdanovic et al, 1994), monkey, and human (De Giorgio et al, 1994;Uemura et al, 1997).…”