Long-term role of nitric oxide in the enteric nervous system of the transplanted rat intestine.
We investigated the long-term changes of the nitric oxide (NO)-related neural component after syngeneic total small bowel transplantation in rats. In the present study, the NO-related neural component was examined using the electrophysiological and NADPH-diaphorase histochemical technique. The rats were divided into four groups: an untreated young adult control group, an untreated 2-year-old control group, a group killed 1 month after transplantation, and a group killed 2 years after transplantation. A superfusion apparatus was used to evaluate the response of jejunal strips to electrical transmural stimulation. In the presence of adrenergic and cholinergic blockade, the inhibitory effect of L-N(G)-nitro arginine (L-NNA; a nitric oxide synthesis inhibitor) on nonadrenergic, noncholinergic (NANC) relaxation was expressed as a L-NNA-sensitive component. The L-NNA-sensitive component accounted for 41.6 +/- 4.6% (mean +/- SE), 43.1 +/- 3.5%,54.6 +/- 4.1%, and 55.8 +/- 3.5% in the young control group, 2-year control group, 1-month transplant group, and 2-year transplant group, respectively, being significantly higher in the transplant groups (p < 0.05). The actual strength of the L-NNA-sensitive component was 0.24 +/- 0.03 (mean +/- SE), 0.26 +/- 0.02, 0.44 +/- 0.04, and 0.46 +/- 0.04 mg of tension per mg of wet weight, respectively, also being significantly higher in the transplant groups (p < 0.001). In addition, the percentage of NADPH-diaphorase-positive fibers was 24.1 +/- 1.1% (mean +/- SE), 25.5 +/- 1.4%, 31.0 +/- 1.6%, and 30.9 +/- 2.0%, respectively, being significantly higher in the transplant groups (p < 0.05). These results suggest that NO neurons in the intrinsic jejunal nervous system have an adaptive role in maintaining intestinal graft motility.
Second Department of Surgery, Hyogo College of Medicine, Nishinomiya, Japan.
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Ishii
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Nakao
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Nishizaki
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Ichii
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Hatada
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Yamamura
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D008058:Dihydrolipoamide Dehydrogenase / Q000032:analysis; D004558:Electric Stimulation; D017615:Enteric Nervous System / Q000502:physiology*; D006145:Guanethidine / Q000494:pharmacology; D066298:In Vitro Techniques; D007421:Intestine, Small / Q000294:innervation / Q000502:physiology* / Q000637:transplantation*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000294:innervation / Q000502:physiology* / Q000637:transplantation*; D009569:Nitric Oxide / Q000502:physiology*; D019335:Nitroarginine / Q000494:pharmacology; D051381:Rats; D011917:Rats, Inbred Lew; D014185:Transplantation, Isogeneic / Q000502:physiology*
D019335:Nitroarginine; D009569:Nitric Oxide; D001285:Atropine; D008058:Dihydrolipoamide Dehydrogenase; D006145:Guanethidine