Keimei Munakata

Clinical and histologic studies of neuronal intestinal dysplasia

Over a period of 10 years we have treated 10 patients with neuronal intestinal dysplasia (NID), including 3 in whom the entire intestinal tract was affected by NID, and one in whom small intestinal NID coexisted with total colonic aganglionosis. Three of these 4 patients have died and the one survivor requires parenteral feeding. The six patients with less extensive NID have all been treated successfully; three have required surgery (Duhamel procedure in 2 and colostomy in 1), but 3 responded to conservative measures. We have made detailed histologic studies, including acetylcholinesterase activity in all cases, silver impregnation studies in 4, and immunohistochemical investigation of the peptidergic innervation of the bowel in one case. Follow-up rectal biopsies have not shown any significant morphological changes with time, but functional improvement does occur and we suggest that the myenteric ganglia in NID may have the capacity for functional maturation.

A role of nitric oxide in Hirschsprung's disease

Nitric oxide (NO) has recently been shown to be a neurotransmitter in the nonadrenergic noncholinergic (NANC) inhibitory nerves in the gastrointestinal tract. To clarify the significance of NO in Hirschsprungs disease (HD), enteric nerve responses in colonic tissue obtained from HD patients were investigated. Colonic tissue specimens were obtained from four patients with HD and from 11 patients without constipation who were used as controls. A mechanograph was used to evaluate in vitro colonic responses to electrical field stimulation (EFS) of the adrenergic and cholinergic nerves before and after treatment with various autonomic nerve blockers, and NG-nitro-L-arginine (L-NNA) and L-arginine with the following results: (1) NANC inhibitory nerves were found to act on normal human colon, but had no effect on aganglionic colon; (2) L-NNA concentration dependently inhibited the relaxation in response to EFS in the normal colon, but had no effect on aganglionic colon; and (3) this inhibitory effect was reversed by L-arginine in the normal colon, but had no effect on the aganglionic colon. Nitric oxide mediates the relaxation reaction of NANC inhibitory nerves in the human colon, but the effect of NO was absent in aganglionic colon. The loss of action by NO may be implicated in the impaired motility observed in aganglionic colon.

ROLE OF NON-ADRENERGIC NON-CHOLINERGIC INHIBITORY NERVES IN THE COLON OF PATIENTS WITH ULCERATIVE COLITIS

Abstract: The cause of impaired colonic motility in patients with ulcerative colitis (UC) is unknown. The non-adrenergic non-cholinergic (NANC) inhibitory nervous system is one of the most important factors in the enteric nervous system of human gut. To assess the physiological significance of NANC inhibitory nerves in the colon of patients with UC, we investigated the enteric nerve responses of colonic tissues from patients with this disease. Colonic tissues were obtained from the lesional sigmoid colons of six patients with UC. Normal sigmoid colonic tissues obtained from ten patients with colonic cancer were used as controls. A mechanographic technique was used to evaluate in-vitro muscle responses to the electrical field stimulation (EFS) of adrenergic and cholinergic nerves before and after treatment with various autonomic nerve blockers. NANC inhibitory nerves were found to act on both normal colon and the lesional colon of patients with UC, but colon with UC was more strongly innervated by NANC inhibitory nerves than was the normal colon. These findings suggest that NANC inhibitory nerves play an important role in the impaired motility observed in the colon of patients with UC.

Electrophysiologic assessments in pudendal and sacral motor nerves after ileal J-pouch-anal anastomosis for patients with ulcerative colitis and adenomatosis coli

PURPOSE: To clarify neurologic function with respect to external anal sphincter and puborectalis muscles after J configuration ileal J-pouch-anal anastomosis for patients with ulcerative colitis and adenomatosis coli, we examined the terminal motor latency in the pudendal and sacral motor nerve (S2-4). METHODS: Latency of the response in the external anal sphincter muscle following digitally directed transrectal pudendal nerve stimulation (PNTML) and in the puborectalis muscle following transcutaneous magnetic stimulation of the cauda equina at the levels S2-4 (SMNLTSS) were measured in 12 patients with ileal J-pouchanal anastomosis; they were divided into a group with continence (7 cases) and a group with soiling (5 cases). Results were compared with data obtained from 12 patients before operation and 15 controls. RESULTS: Conduction delay of PNTML and SMNLTSS in patients with soiling was longest, followed by delay in those without any soiling, then delay in patients before operation, and then controls. In addition, significant differences were also noted between conduction delay of PNTML in controls and those who are incontinent and experience soiling(P< 0.05 andP< 0.01, respectively), and there were significant differences also noted between conduction delay of PNTML in patients before operation and those who are incontinent and experiencing soiling(P< 0.05 andP< 0.01, respectively). Conduction delay of PNTML and SMNLTSS were found in patients before operation rather than in controls. No significant differences were noted between conduction delay of PNTML and SMNLTSS in patients before operation and controls. Significant differences were also noted between conduction delay of PNTML and SMNLTSS in patients who are incontinent and experiencing soiling(P< 0.01, respectively). CONCLUSION: These findings support the hypothesis that soiling after this procedure may be partially caused by damage to pudendal and sacral motor nerves (S2-4).

The role of motilin and cisapride in the enteric nervous system of the lower esophageal sphincter in humans.

To assess the pharmacophysiological significance of the enteric nervous system and the responses of the human lower esophageal sphincter (LES) to motilin and cisapride, the mechanical responses of esophgeal tissues from six patients with esophageal cancer and seven patients with gastric cancer were investigated. Circular muscle reactions were recorded to evaluate the in vitro esophageal responses to electrical field stimulation (EFS), motilin, and cisapride, evoking the adrenergic and cholinergic nerves before and after treatment with various autonomic nerve blockers. The findings of this study revealed that: cholinergic nerves are mainly involved in the regulation of enteric nerves in the steady state, while nonadrenergic non-cholinergic (NANC) inhibitory nerves also exist; motilin may act both via nerves and also directly on the LES smooth muscle; and cisapride releases acetylcholine from the end of the postganglionic fiber of the cholinergic nerve in human LES thereby inducing contraction of the LES. These results suggest that cholinergic and NANC inhibitory nerves play an important role in human LES, and that motilin and cisapride is clinically useful for improving the impaired LES of patients with gastroesophageal reflux.

Relationship between nitric oxide and non-adrenergic non-cholinergic inhibitory nerves in human lower esophageal sphincter

Nitric oxide (NO) has recently been shown to be a neurotransmitter in the non-adrenergic non-cholinergic (NANC) inhibitory nerves in the gastrointestinal tract. To clarify the the role of NO in the human lower esophageal sphincter (LES), enteric nerve responses in lower esophageal tissue specimens obtained from patients with esophageal cancer (n=7) and patients with gastric cancer (n=6) were investigated. A mechanographic technique was used to evaluate in vitro LES muscle responses to electrical field stimulation (EFS) of adrenergic and cholinergic nerves before and after treatment with various autonomic nerve blockers, including NG-nitro-L-arginine (L-NNA) and L-arginine. Findings were: (1) Cholinergic nerves were those mainly involved in the regulation of enteric nerve responses to EFS in the steady state, and NANC inhibitory nerves acted on the LES; (2) L-NNA concentration-dependently inhibited the relaxation in response to EFS in the LES; and (3) this inhibitory effect in the LES was reversed by L-arginine. These findings suggest that cholinergic and NANC inhibitory nerves play important roles in regulating contraction and relaxation of the human LES, and that NO plays an important role as a neurotransmitter in NANC inhibitory nerves of the human LES.

A role of peptidergic nerves in the internal anal sphincter of Hirschsprung's disease.

BACKGROUND It is not clear what contribution the internal anal sphincter makes to the impaired motility observed in patients with Hirschsprungs disease (HD). Neuropeptides have recently been shown to be neurotransmitters in the nonadrenergic, noncholinergic inhibitory and excitatory nerves in the human gut. To clarify the physiologic significance of vasoactive intestinal polypeptide and substance P in the internal anal sphincter of HD (aganglionosis), we investigated the enteric nerve responses on lesional and normal internal anal sphincter muscle strips above the dentate line. METHODS The lesional and normal internal anal sphincter muscle strips above the dentate line were derived from patient with HD (9 cases) and patients who underwent rectal amputation for low rectal cancers (8 cases). A mechanographic technique was used to evaluate in vitro muscle responses to these peptides of adrenergic and cholinergic nerves before and after treatment with various autonomic nerve blockers. RESULTS Nonadrenergic, noncholinergic inhibitory nerves were found to act on the normal internal anal sphincter but had no effect on the enteric nerves in aganglionosis. Peptidergic (vasoactive intestinal polypeptide and substance P) nerves were found to act on normal colon, but no effect was observed in the aganglionic internal anal sphincter. CONCLUSIONS These findings suggest that peptidergic nerves play an important role in the impaired motility observed in the internal anal sphincter with HD.

Sacral nerve terminal motor latency after ileal J pouch-anal anastomosis for ulcerative colitis

Using a new transcutaneous magnetic stimulation technique, sacral nerve terminal motor latencies (SNTML) were measured after ileal J pouch-anal anastomosis in eight patients with ulcerative colitis, and the results were compared with those obtained from 15 normal subjects. The conduction delay of the SNTML in patients with soiling was significantly longer than that of the continent group as well as that of normal subjects (P<0.01). There were no significant differences in the conduction delay between the continent group and the control subjects. These findings therefore support the hypothesis that such soiling, which is sometimes seen after ileal J pouch-anal anastomosis, is partly due to damage to the sacral nerves.

Terminal Motor Latency in the Pudendal Nerves After Colectomy with Mucosal Proctectomy and Ileal J Pouch-anal Anastomosis for Ulcerative Colitis

Pudendal nerve terminal motor latencies (PNTML) were measured in eight patients with ulcerative colitis who underwent colectomy with mucosal proctectomy and ileal J pouch-anal anastomosis, using a new digitally directed transrectal stimulation and recording technique, and the results were compared with data obtained from 15 control subjects. The conduction delay of PNTML in the patients with some degree of fecal incontinence was the longest, followed by those without any incontinence, and then the control subjects. These findings support the hypothesis that fecal incontinence after this procedure may be partially caused by damage to the pudendal nerve.

Monocyte production of nitric oxide (NO) in severe acute pancreatitis

To clarify the correlation between the kinetics of nitric oxide (NO) production and the occurrence of organ dysfunction in acute pancreatitis, we examined the production of NO2 and NO3 by monocytes in five patients with severe pancreatitis and organ dysfunction (four males and one female, aged 24–52 years: group S), and compared the results with those in five patients with mild pancreatitis (three males and two females, aged 24–52 years: group M) and 12 healthy volunteers (9 males and three females, aged 25–44: group C). The time course of induced NO production by cultured monocytes obtained from these subjects was also examined, using a NO-sensitive electrode. The levels of NO2 and NO3 production by monocytes in vitro, with or without stimulation, were significantly higher (P<0.05), the time required for NO production by cultured monocytes was significantly shorter (P<0.01), and the duration of NO production by monocytes was significantly longer (P<0.01), in group S compared with the other groups. These findings indicate that, in patients with severe acute pancreatitis, the NO-producing mechanism of monocytes is not only primed but also triggered. Further-more, it seems that NO production by monocytes is directly correlated with the incidence of organ dysfunction.