Distribution of nitric oxide synthase in stomach wall in rats.

Abstract

It has been shown that neuronal nicotinamide adenene dinucleotide phosphate-diaphorase (NADPH-d) may correspond to the neuronal nitric oxide synthase (NOS), and may be used as a marker for NOS in the central and peripheral nervous system. Thus, NADPH-d histochemistry provides us with a mean to specifically identify neurons producing nitric oxide (NO)[1,2]. Recent pharmacological and physiological-stu-dies demonstrated that NO is a neurotransmitter in the non-adrenergic non-cholinergic (NANC) in-hibitory nerves in the mammalian gastrointestinal tract. It may play a very important role in then euronal regulation of gut. NOS activity is present in neurons and fibers of the major enteric nerve layer in intestine[3]. However, there have been far fewer studies of NOS activity in stomach wall. If NO is a transmitter of NANC in hibitory nerves, it should be present in neurons innervating the muscularis. What proportion of nerves produce NO? What is the pattern of innervation of these neurons? To answer these questions, we examined the distribution and morphological feature of NOS positive neurons in the stomach wall with improved whole mount preparation technique.