EFFECTS OF TRANSPORT STRESS ON THE INTESTINES INVOLVING NEURONAL NITRIC OXIDE SYNTHASE

● Transport stress declined the level of leukocytes including lymphocytes in rat serum. ● Transport stress destroyed intestinal integrity of rat. ● The muscular layer thickness of intestine was decreased after transport stress. ● nNOS expression and nNOS-positive neurons were reduced in rat after transport stress. Transport stress is commonly suffered by animals with gastrointestinal dysfunction a common symptom. Currently, the mechanisms of transport stress-induced intestine impairment are largely unknown. The aim of this study was to investigate the effects of transport stress on the expression of neuronal nitric oxide synthase (nNOS) and the distribution of nNOS-positive neurons of the intestines in rats and to explore the neuroendocrine mechanism of transport stress. In this study, Sprague Dawley rats (n = 6) were subjected on a constant temperature shaker for 1 (S1d) or 3 d (S3d). Rats exhibited increased serum glucose and diminished total number of leukocytes, in which lymphocytes level was also decreased in the S1d group (P < 0.05). Also, normal intestinal morphology was disrupted in the S1d rats, and the thickness of muscle layers was decreased in duodenum, jejunum and colon of S3d rats. In addition, it was found that nNOS expression, as well as the number of nNOS-positive neurons in the myenteric plexus were downregulated in duodenum, jejunum and colon of S3d rats compared with that of unstressed rats (P < 0.05). These data reveals that transport stress induced intestinal damage and uncovers potential action mechanisms that nNOS-positive neurons and nNOS expression might be involved in modulating this process.