Neurochemical features of endomorphin-2-containing neurons in the submucosal plexus of the rat colon

AIM:To investigate the distribution and neurochemical phenotype of endomorphin-2(EM-2)-containing neurons in the submucosal plexus of the rat colon.METHODS:The mid-colons between the right and left flexures were removed from rats,and transferred into Kreb's solution. For whole-mount preparations,the mucosal,outer longitudinal muscle and inner circularmuscle layers of the tissues were separated from the submucosal layer attached to the submucosal plexus. The whole-mount preparations from each rat mid-colon were mounted onto seven gelatin-coated glass slides,and processed for immunofluorescence histochemical double-staining of EM-2 with calcitonin gene-related peptide(CGRP),choline acetyltransferase(Ch AT),nitric oxide synthetase(NOS),neuron-specific enolase(NSE),substance P(SP) and vasoactive intestinal peptide(VIP). After staining,all the fluorescence-labeled sections were observed with a confocal laser scanning microscope. To estimate the extent of the co-localization of EM-2 with CGRP,Ch AT,NOS,NSE,SP and VIP,ganglia,which have a clear boundary and neuronal cell outline,were randomly selected from each specimen for this analysis. RESULTS:In the submucosal plexus of the mid-colon,many EM-2-immunoreactive(IR) and NSE-IR neuronal cell bodies were found in the submucosal plexus of the rat mid-colon. Approximately 6 ± 4.2 EM-2-IR neurons aggregated within each ganglion and a few EM-2-IR neurons were also found outside the ganglia. The EM-2-IR neurons were also immunopositive for Ch AT,SP,VIP or NOS. EM-2-IR nerve fibers coursed near Ch AT-IR neurons,and some of these fibers were even distributed around Ch AT-IR neuronal cell bodies. Some EM-2-IR neuronal cell bodies were surrounded by SP-IR nerve fibers,but many long processes connecting adjacent ganglia were negative for EM-2 immunostaining. Long VIP-IR processes with many branches coursed through the ganglia and surrounded the EM-2-IR neurons. The percentages of the EM-2-IR neurons that were also positive for Ch AT,SP,VIP or NOS were approximately 91% ± 2.6%,36% ± 2.4%,44% ± 2.5% and 44% ± 4.7%,respectively,but EM-2 did not co-localize with CGRP. CONCLUSION:EM-2-IR neurons are present in the submucosal plexus of the rat colon and express distinct neurochemical markers.     

The neurochemical coding and projections of circular muscle motor neurons in the human colon

BACKGROUND & AIMS: Enteric neurons can be characterized by their chemical coding, projections, and morphology. The aim of this study was to describe the different classes of human colonic circular muscle motor neurons. METHODS: Human colonic circular muscle motor neurons were identified by retrograde tracing with 1,1'-didodecyl 3,3,3',3'- indocarbocyanine perchlorate (Dil) applied to the circular muscle layer. Whole-mount preparations of the myenteric plexus were then double-labeled with antisera to choline acetyltransferase (ChAT) and/or nitric oxide synthase (NOS), or NOS and vasoactive intestinal peptide (VIP), and the position and immunoreactivity of Dil-filled neurons were recorded. RESULTS: Fifty-two percent of all Dil-filled neurons were ChAT immunoreactive, and 86% of these projected up to 11 mm orally, with 14% projecting short distances anally. Forty-eight percent of the Dil-filled neurons were NOS immunoreactive, and 77% of these projected up to 19 mm anally, with 23% projecting no more than 6 mm orally. A subpopulation of these NOS-immunoreactive motor neurons were also VIP- immunoreactive. A small population of myenteric neurons was immunoreactive for both ChAT and NOS, but none projected to the circular muscle. NOS-immunoreactive motor neurons projected for longer distances than those with ChAT immunoreactivity and were larger. CONCLUSIONS: There are two classes of human colonic motor neurons: one is excitatory (ChAT-immunoreactive) and mainly projects orally and the other is inhibitory (NOS +/- VIP immunoreactive) and projects preferentially anally. (Gastroenterology 1997 Dec;113(6):1916-23)     

Enteric nerves in diabetic rats: increase in vasoactive intestinal polypeptide but not substance P

The distribution of vasoactive intestinal polypeptide (VIP) and substance P-like immunoreactivities was studied by immunohistochemistry in the myenteric plexus and circular muscle layer of the ileum and proximal colon of rats 8 wk after induction of diabetes with streptozotocin. A consistent increase was observed in fluorescence intensity of VIP-like immunoreactivity in the nerve fibers, and intensely stained cell bodies were significantly more frequent in the myenteric plexus of the ileum (p less than 0.001) from diabetic animals. Some varicosities of VIP-like immunoreactive fibers in the myenteric plexus appeared to be enlarged. Vasoactive intestinal polypeptide-like immunoreactivity was increased and VIP-like immunoreactive nerves appeared thicker in the circular muscle layer of both diabetic ileum and proximal colon. The VIP levels were measured biochemically in tissue consisting of the smooth muscle layers and myenteric plexus. A significant increase in the VIP content per centimeter of intestine was found in both the ileum (p less than and proximal colon (p less than 0.01) from diabetic rats. In contrast, no apparent change in substance P innervation was observed immunohistochemically in the myenteric plexus and circular muscle layer of either diabetic ileum or proximal colon when compared with controls. The results are discussed in relation to the symptoms of autonomic neuropathy of the gut in diabetes.     

Localization of neurokinin B receptor in mouse gastrointestinal tract

AIM: To observe the location of neurokinin receptor (NK3r)in the mouse gastrointestinal tract.METHODS: The abdomen of 8 male Kunming mice wereopened under anaesthesia with sodium pentobarbital. Theexposed gut organs were cleaned and kept moisture andtemperature. Then the esophagus, jejulum, ileum, colon,etc were respectively cut and the segments from thestomach to the distal colon were opened along themesenteric border. A circular 4mm ～ 6mm enteric part(pieces of 1 cr2 were to be prepared) and mucosa andsubmucosa were removed, then the longitudinal musclelayer was pulled off from the circular muscle layer undermicrophotography. They were rinsed in 50nmol @ L-1potassium phosphate-buffered saline ( PBS ).Immunohistochemistry and immunoreactive fluorescencewere used in the staining procedure.RESULTS: There was not NK3r-Like(-Li) positive material onthe smooth muscle cells of the esophagus, stomach,intestines and other regions. The nerve cell bodies withimmunoreactivity for NK3r were mainly distributed in thesubmucousal nerve plexus or myenteric nerve plexus of thegastrointestinal tract except for the esophagus, stomachand rectum. The reaction product was located on thesurface of the nerve cell plasma. lt was observedoccasionally in the cell plasma endosomes, but was veryweakly stained. Among the NK3-Like positive neurons in theplexus, the morphological type in many neurons' appenaedlike Dogiel Ⅱ type cells. Some neuron cell bodies were big,having many profiles, Some were long ones or havinggrading structure. Cell bodiy diameter was about 10μm-46μmand 8μm-42μm in myenteric plexus and submucous plexus.CONCLUSION: This study not only described the distributionof neurokinin B receptor in the mouse gut, but alsoprovided a morphological basis for deducing the functionalidentity of the NK3r-LI immunoreactivity neurons,suggesting the possibility that these neurons were closelyrelated to gastrointestinal tract contraction and relaxingactivity.     

Distribution of mast cells in human ileocecal region

The number and histochemistry of mast cells were analyzed in surgical specimens of the ileocecal junction and neighboring intestinal segments. All the basophilic cells contained tryptase and some were immunoreactive for chymase, vasoactive intestinal polypeptide, or nitric oxide synthase. The medium density of mast cells per square millimeter was 31.90, 110.38, 72.83, 29.80, and 32.70, in the mucosa, submucosa, inner circular, outer circular, and longitudinal muscle layers, respectively. Mast cell density was higher at the ileocecal junction (for all layers together, 79.29 mast cells/mm²) than elsewhere (mast cells/mm²: ileum, 52.29; cecum, 59.22; cecocolonic junction, 54.65; ascending colon, 48.63). The differences among layers and among segments were significant and might be due to layer- and region-specific mast cell roles. Mast cell richness in the muscle coat, especially in the inner circular muscle layer, might be important in regulating its motility.     

Effect of chagas' disease on nitric oxide-containing neurons in severely affected and unaffected intestine

PURPOSE: The pathophysiology of Chagas' disease is incompletely understood. Neuronal nitric oxide has been cited as a candidate neurotransmitter responsible for relaxation of the internal anal sphincter. Neuronal nicotinamide adenine dinucleotide phosphate diaphorase can be used as a marker for neuronal nitric oxide synthase. This study was designed to examine the alterations of the nitric oxidecontaining neurons in the enteric nervous system of the colon of patients who underwent resections for advanced megacolon and to compare these specimens with small-bowel specimens from the same patients and with specimens from control subjects. METHODS: Specimens from resected rectum and extramucosal small-bowel biopsy specimens from 11 patients with Chagas megacolon but no apparent small-bowel clinical involvement were compared with the uninvolved colon and jejunum of 10 control patients with colon cancer. Tissues were fixed in Zamboni solution and evaluated by histochemistry for nicotinamide adenine dinucleotide phosphate diaphorase-containing neurons. Reactivity was evaluated on a 0 to 4 scale in the longitudinal muscle, myenteric plexus, circular muscle, submucosal plexus, and mucosa. RESULTS: Specimens from control patients showed well-stained myenteric and submucosal neurons and an abundant network of terminal nerve fibers in the muscle layers. Chagasic specimens had decreased staining in all layers of the gut. Overall there was a statistically significant decrease in nicotinamide adenine dinucleotide phosphate diaphorase-containing neurons. Biopsy specimens from clinically uninvolved small bowel of patients with Chagas' disease also showed decreased reactivity, but to a lesser degree. CONCLUSIONS: Nicotinamide adenine dinucleotide phosphate diaphorase activity is decreased in patients with advanced megacolon. The alterations are more relevant in the myenteric plexus and the circular muscle. Reactivity is also diminished in the clinically uninvolved small bowel, but to a lesser extent.     

氩气刀结合黏膜下注射治疗结肠息肉的安全性研究

目的探讨氩气刀结合黏膜下注射治疗结肠息肉的安全性。方法取健康肉猪的新鲜乙状结肠30份,每份均设立实验组（黏膜下注射后氩气烧灼）和对照组（直接氩气烧灼）,烧灼后病理组织学观察猪结肠壁各层损伤情况并行组间对比分析。另选择10例结肠广基息肉患者（息肉直径1～2cm,厚度在3mm以内）,均分成观察组（黏膜下注射后氩气烧灼）和对照组（直接氩气烧灼）,烧灼后超声内镜观察人结肠壁各层损伤情况。结果病理组织学观察显示,对照组损伤猪结肠固有肌层5份、黏膜下层25份（上1／34份、中1／312份、下1／39份）,实验组损伤猪结肠黏膜下层26份（上1／322份、中1／34份）、黏膜肌层4份,2组差异有统计学意义（P〈0．01）。超声内镜观察显示：对照组人结肠黏膜层与黏膜下层融合、层次不清,局部黏膜下层与固有肌层边缘毛糙、不规则;观察组人结肠1、2层边缘稍毛糙模糊,其余各层层次界限清晰。结论黏膜下注射对氩气刀烧灼损伤具有保护作用,可减少结肠息肉患者氩气刀治疗发生穿孔的概率。     

An in vitro study of the projections of enteric vasoactive intestinal polypeptide-immunoreactive neurons in the human colon

The anatomical basis of the peptidergic neural control of the human colon is largely unknown. In this study, in vitro retrograde tracing methods have been used on fresh human colon to determine the projection pathways of the enteric nerves and, in particular, those containing vasoactive intestinal polypeptide, one of the most abundant and potent of the gut neuropeptides. Two components of the submucous plexus were identified, the inner one projecting to the lamina propria, and the outer to the circular muscle. The lengths of projections within the submucous plexus were up to 5-14 mm in all directions. Myenteric ganglion cells projected to both longitudinal and circular muscles, for distances of up to only 5 mm. The subpopulation of nerves containing vasoactive intestinal polypeptide arose mainly from the submucous plexus and projected up to 6.5 mm anally, 5 mm orally, and 14 mm within the submucous layer to the mucosa or circular muscle. These findings provide entirely new data on the neuroanatomy of the human colon and may help in the understanding of the neural control of colonic secretion and motility.     

Distribution of vasoactive intestinal polypeptide and substance P receptors in human colon and small intestine

Vasoactive intestinal polypeptide (VIP) and substance P are found in neurons in the lamina propria and submucosa and muscularis propria of human small intestine and colon. VIP receptors coupled to adenylate cyclase are present on epithelial, smooth muscle, and mononuclear cells. This study analyzes the distribution of[¹²⁵I]VIP binding and [¹²⁵]substance P in human colon and small intestine using autoradiographic techniques. [¹²⁵I]VIP binding was present in high density in the mucosal layer of colon and small intestine. [¹²⁵I]VIP binding was not significantly greater than nonspecific binding in smooth muscle layers or the lymphoid follicles. In contrast, [¹²⁵I]substance P binding was present in high density over the colonic muscle but was not present over the mucosal layer. In human colon cancer, [¹²⁵I]VIP grain density over the malignant tissue was only slightly higher than background. These autoradiographic studies of [¹²⁵I]VIP binding indicate that the highest density of VIP receptors was found in the small intestine and superficial colonic mucosa, whereas the density of substance P receptors was highest over the smooth muscle layers. These findings suggest a mismatch between immunochemical content of the peptide and autoradiographic density of the receptor.This work was supported by funds from the Research Service of the Veterans Administration.     

Multiple endocrine neoplasia 2B: Differential increase in enteric nerve subgroups in muscle and mucosa

Multiple endocrine neoplasia 2B(MEN2B) is a rare syndrome caused by an activating mutation of the RET gene, leading to enteric gangliomatosis. This child presented with constipation at 1-mo old, was diagnosed with MEN2 B by rectal biopsy at 4 mo, had thyroidectomy at 9 mo and a colectomy at 4 years. We studied the extent of neuronal and nerve fibre proliferation and which classes of enteric nerves are affected by examining the colon with multiple neuronal antibodies. Resected transverse colon was fixed, frozen, sectioned and processed for fluorescence immunohistochemistry labelling with antibodies against TUJ1, Hu, ChAT, NOS, VIP, SP and CGRP and cKit. Control transverse colon was from the normal margin of Hirschsprung(HSCR) colon(4-year-old) and a child with familial adenomatous polyposis(FAP, 12 year). Myenteric ganglia were increased in size to as wide as the circular muscle. There was a large increase in nerve cells and nerve fibres. ChAT-, NOS-, VIP-and SP-immunoreactive nerve fibres all increased in the myenteric ganglia. NOS-IR nerves preferentially increased in the muscle, while VIP and SP increased in submucosal ganglia and mucosal nerve fibres. The density of ICC was normal. RET overactivation in MEN2B lead to a large increase in intrinsic nerve fibres in the myenteric and submucosal ganglia, with a relative increase in NOS-IR nerve fibres in the circular muscle and VIP and SP in the submucosal ganglia and mucosa. The changes were associated with severe constipation resulting in colectomy at 4 years.     

Esophageal obstruction due to intermuscular hematoma following pneumatic dilatation.

A case of incomplete esophageal perforation with an intermuscular hematoma is presented. Unlike previously described submucosal or intramural perforations, this case involved mucosa, submucosa, and the inner circular muscle layer but was limited by the outer longitudinal layer. Nonsurgical treatment was followed when the clinical picture of an incomplete perforation without mediastinal soilage was considered. Surgery was done when evidence of impending extension of the process outside the esophagus developed.     

Morphological study on the motility of the human colon

We tried to make a clear three-dimensional picture of the autonomic nerves in the wall of the human colon, using a Golgi method rarely applied to human materials. At autopsy, sigmoid colon without mucosal lesions were collected from 16 males after sudden death from apoplexy, head injury, or myocardial infarction. These materials were fixed in 10% formalin, impregnated with a modified Golgi method and embedded in celloidin. Then three-dimensional serial sections were made and observed with a light microscope. Many fine nerve fibers formed a plexus in the subserosa, muscular layer, submucosa, and mucosa. The myenteric plexus was made up of rectangular meshes of nerve fiber bundles. However, unlike myenteric plexus, no regular mesh was found in the submucosal plexus. Further, nerve fibers connecting myenteric and submucosal plexus were observed. It may be concluded from these findings that there exist nerve pathways regulating intestinal motility between myenteric and submucosal plexus.     

Preponderance of inhibitory versus excitatory intramuscular nerve fibres in human chagasic megacolon

Introduction

Megacolon, chronic dilation of a colonic segment, is a frequent sign of Chagas disease. It is accompanied by an extensive neuron loss which, as shown recently, results in a partial, selective survival of nitrergic myenteric neurons. Here, we focused on the balance of intramuscular excitatory (choline acetyltransferase [ChAT]-immunoreactive) and inhibitory (neuronal nitric oxide synthase [NOS]- as well as vasoactive intestinal peptide [VIP]-immunoreactive) nerve fibres.

Materials and methods

From surgically removed megacolonic segments of seven patients, three sets of cryosections (from non-dilated oral, megacolonic and non-dilated anal parts) were immunhistochemically triple-stained for ChAT, NOS and VIP. Separate area measurements of nerve profiles within the circular and longitudinal muscle layers, respectively, were compared with those of seven non-chagasic control patients. Additionally, wholemounts from the same regions were stained for NOS, VIP and neurofilaments (NF).

Results

The intramuscular nerve fibre density was significantly reduced in all three chagasic segments. The proportions of inhibitory (NOS only, VIP only, or NOS/VIP-coimmunoreactive) intramuscular nerves were 68?%/58?% (circular/longitudinal muscle, respectively) in the controls and increased to 75?%/69?% (oral parts), 84?%/76?% (megacolonic) and 87?%/94?% (anal) in chagasic specimens. In the myenteric plexus, NF-positive neurons co-staining for NOS and VIP also increased proportionally. The almost complete lack of dendritic structures in ganglia of chagasic specimens hampered morphological identification.

Discussion and conclusion

We suggest that preponderance of inhibitory, intramuscular nerve fibres may be one factor explaining the chronic dilation. Since the nerve fibre imbalance is most pronounced in the anal, non-dilated segment, other components of the motor apparatus (musculature, interstitial cells, submucosal neurons) have to be considered.     

Autoradiographic localization of mu- and delta-type opioid receptors in the gastrointestinal tract of the rat and guinea pig

The distribution of delta- and mu-type opioid binding sites in the gastrointestinal tract of the rat and guinea pig was studied by autoradiography after in vitro incubation of tissue slices with 3H-D-Ala2,D-Leu5-enkephalin, and 3H-naloxone or 3H-dihydromorphine to locate delta- and mu-type opioid receptors, respectively. In the gastric fundus, both mu- and delta-type binding sites were found to occur associated with the circular muscle, muscularis mucosae, and submucosal plexus, whereas in the corpus and antrum, binding was located primarily in the submucosal plexus, deep muscular plexus, and mucosa. Some mu-type opioid receptor sites were present in the myenteric plexus. A dense distribution of both mu- and delta-type binding sites was observed throughout the mucosa of the duodenum and ileum of the rat. In guinea pig ileal tissue, however, only mu-type binding could be demonstrated, occurring in the submucosal plexus and diffusely over the muscle layers. Endogenous opioid peptides, acting at these receptors sites, might be involved in the control of gastrointestinal motility, endocrine and exocrine secretions, as well as intestinal fluid and electrolyte transport.     

Altered colonic transit in TNBS-induced experimental colitis in guinea pig and distribution of nitric oxide synthase in the colonic wall]

BACKGROUND/AIMS: Inflammation-induced alterations in smooth muscle contractility may be due to the effects on smooth muscle itself, neurotransmitters or enteric nerves. In dextran sulfate sodium-induced colitic rat, the delay in colonic transit was caused by decreased activity and production of neuronal nitric oxide synthase (nNOS) in the myenteric plexus of the distal colon. The aim of this study was to investigate the relationship between the delay in colonic transit and the distribution of inducible NOS (iNOS) and nNOS immunoreactive cells in the myenteric plexus of trinitrobenzene sulfonic acid (TNBS)-induced colitic guinea pig. METHODS: Sacrificed and their colonic tissues of forty-five TNBS-induced colitic guinea pigs were used to measure the colonic transit, and analyzed by immunohistochemistry. RESULTS: Colonic transit was delayed significantly at 3, 7 and 14 days after administration of TNBS. In control, nNOS immunoreactivity was present in the mucosa, submucosa, lamina propria, and ganglion cells of the myenteric plexus, while after TNBS treatment, reduced nNOS cells were found. However, the number of nNOS ganglion cells in the myenteric plexus was similar to those seen in controls. After administration of TNBS, iNOS immunoreactivity was increased in the mucosa and submucosa, but the number of iNOS positive ganglion cells in the myenteric plexus was not changed compared to control. CONCLUSIONS: It is suggested that in TNBS-induced guinea pig colitis, delayed colonic transit is not associated with the expression of nNOS nor iNOS in the myenteric plexus.     

Distribution of nitric oxide synthase in stomach myenteric plexus of rats

AIM:To study the distribution of nitdc oxide synthese(NOS)in rat stomach myenteric plexus.METHODS:The distribution of NOS in gastric wall wasstudied in quantity and location by the NADPH-diaphorase(NDP)histochemical staining method and whole mountpreperation technique.RESULTS:NOS was distributed in whole stomach wall,mostof them were located In myenteric plexus,and distributed insubmucosal plexus.The shape of NOS positive neuronswas baslcally similar,most of them being round and oval inshape.But their density,size and staining intensity variedgreatly in the different parts of stomach.The density was 62±38 cells/mm~2(antrum),43±32 cells/mm~2(body),and 32±28 cells/mm~2(fundus),respectively.The size andstaining intensity of NOS positive neurons in the funduswere basically the same,the neurons being large and darkstained,while they were obviously different in antrum.Inthe body of the stomach,the NOS positive neurons were inan Intermediate state from fundus to antrum.There weresome beedlike structures which were strung together byNOS positiva varicosities in nerve fibers,some were closelyadherent to the outer walls of blood vessels.CONCLUSION:Nitric oxide might he involved in themodulation of motility,secretion and blood circulation ofthe stomach,and the significant difference of NOS positiveneurons in different parts of stomach myenteric plexus maybe related to the physiologic function of stomach.     

Expression of 5-HT3 receptors in the rat gastrointestinal tract

BACKGROUND & AIMS: Functional effects mediated via the 5-hydroxytryptamine3 receptor (5-HT3R) can be elicited from both extrinsic and intrinsic neurons innervating the gastrointestinal (GI) tract. Clinically, 5-HT3 antagonists are important in the treatment of emesis and have been used for the treatment of symptoms in functional bowel disease. The aim of the present study was to elucidate the cellular sites of 5-HT3R expression in the rat GI tract using immunohistochemistry. METHODS: Immunohistochemistry was performed in fixed cryostat sections and whole mounts of stomach and intestine of fasted rats, using an affinity-purified antibody directed to a 19-amino acid sequence of the cytoplasmic loop of the 5-HT3R. RESULTS: 5-HT3R immunoreactivity was localized to numerous neurons of the myenteric and submucosal plexus, concentrated primarily near the neuronal plasma membrane, and to fibers in the circular and longitudinal muscles, submucosa, and mucosa. 5-HT3R immunoreactivity was also expressed by interstitial cells of Cajal and a few endocrine cells. Numerous 5-HT3R-positive myenteric neurons were cholinergic, and few neurons coexpressed VIP or SP immunoreactivity. Fibers immunoreactive for 5-HT3R in the duodenal but not ileal mucosa were markedly reduced by subdiaphragmatic vagotomy or chemical denervation of vagal afferents. CONCLUSIONS: These findings indicate that 5-HT3Rs are expressed by distinct cells in the GI tract, including functionally distinct classes of neurons, interstitial cells of Cajal, and endocrine cells. The effects of serotonin mediated by 5-HT3Rs involve the activation of neuronal and nonneuronal pathways.     

Determination of optical properties of normal and adenomatous human colon tissues in vitro using integrating sphere techniques

AIM: The purpose of the present study is to compare the optical properties of normal human colon mucosa/submucosa and muscle layer/chorion, and adenomatous human colon mucosa/submucosa and muscle layer/chorion in vitro at 476.5, 488, 496.5, 514.5 and 532 nm. We believe these differences in optical properties should help differential diagnosis of human colon tissues by using optical methods. METHODS: In vitro optical properties were investigated for four kinds of tissues: normal human colon mucosa/ submucosa and muscle layer/chorion, and adenomatous human colon mucosa/submucosa and muscle layer/ chorion. Tissue samples were taken from 13 human colons (13 adenomatous, 13 normal). From the normal human colons a total of 26 tissue samples, with a mean thickness of 0.40 mm, were used (13 from mucosa/submucosa and 13 from muscle layer/chorion), and from the adenomatous human bladders a total of 26 tissue samples, with a mean thickness of 0.40 mm, were used (13 from mucosa/ submucosa and 13 from muscle layer/chorion). The measurements were performed using a double-integrating-sphere setup and the optical properties were assessed from these measurements using the adding-doubling method that was considered reliable. RESULTS: The results of measurement showed that there were significant differences in the absorption coefficients and scattering coefficients between normal and adenomatous human colon mucosa/submucosa at the same wavelength, and there were also significant differences in the two optical parameters between both colon muscle layer/ chorion at the same wavelength. And there were large differences in the anisotropy factors between both colon mucosa/submucosa at the same wavelength, there were also large differences in the anisotropy factors between both colon muscle layer/chorion at the same wavelength. There were large differences in the value ranges of the absorption coefficients, scattering coefficients and anisotropy factors between both colon mucosa/submucosa, and there were also large differences in these value ranges between both colon muscle layer/chorion. There are the same orders of magnitude in the absorption coefficients for four kinds of colon tissues. The scattering coefficients of these tissues exceed the absorption coefficients by at least two orders of magnitude. CONCLUSION: There were large differences in the three optical parameters between normal and adenomatous human colon mucosa/submucosa at the same laser wavelength, and there were also large differences in these parameters between both colon muscle layer/chorion at the same laser wavelength. Large differences in optical parameters indicate that there were large differences in compositions and structures between both colon mucosa/ submucosa, and between both colon muscle layer/chorion. Optical parameters for four kinds of colon tissues are wavelength dependent, and these differences would be useful and helpful in clinical applications of laser and tumors photodynamic therapy (PDT).     

Pan-colonic decrease in interstitial cells of Cajal in patients with slow transit constipation

BACKGROUND: Interstitial cells of Cajal (ICC) are required for normal intestinal motility. ICC are found throughout the human colon and are decreased in the sigmoid colon of patients with slow transit constipation. AIMS: The aims of this study were to determine the normal distribution of ICC within the human colon and to determine if ICC are decreased throughout the colon in slow transit constipation. PATIENTS: The caecum, ascending, transverse, and sigmoid colons from six patients with slow transit constipation and colonic tissue from patients with resected colon cancer were used for this study. METHODS: ICC cells were identified with a polyclonal antibody to c-Kit, serial 0.5 microm sections were obtained by confocal microscopy, and three dimensional software was employed to reconstruct the entire thickness of the colonic muscularis propria and submucosa. RESULTS: ICC were located within both the longitudinal and circular muscle layers. Two networks of ICC were identified, one in the myenteric plexus region and another, less defined network, in the submucosal border. Caecum, ascending colon, transverse colon, and sigmoid colon displayed similar ICC volumes. ICC volume was significantly lower in the slow transit constipation patients across all colonic regions. CONCLUSIONS: The data suggest that ICC distribution is relatively uniform throughout the human colon and that decreased ICC volume is pan-colonic in idiopathic slow transit constipation.     

Immunocytochemical Localization of Vasoactive Intestinal Peptide and Substance P in the Colon from Normal Subjects and Patients with Inflammatory Bowel Disease

Neuropeptides form a part of the brain-gut axis which may regulate gastrointestinal functions, including immune regulation. Various changes in the neuropeptides--most important, vasoactive intestinal peptide and substances P (VIP and SP)--have been described in inflammatory bowel disease. We employed a sensitive immunoperoxidase (avidin-biotin-peroxidase complex) technique, using anti-VIP and anti-SP antibodies to localize and compare the distribution of VIP and SP in the colon. Colon specimens from 19 normal subjects, eight patients with ulcerative colitis (UC), and eight with Crohn's disease (CD) were used. In the normal colon, VIP and SP immunoreactivity (IR) were localized in the muscularis mucosa, circular muscles, walls of blood vessels, nerve fibers, and some distinct cells, probably enterochromaffin cells. SP-IR was also present in the epithelial cells, mainly along the basolateral domain. VIP-IR was considerably diminished at all locations in patients with UC and CD. However, the SP-IR was increased in UC in the colonic epithelial cells along the basolateral areas. The SP-IR was intense in patients with CD, in the epithelium, the granulomas, cells lining the mucosal fissure, and in the muscle layers. In contrast to normals, SP-IR in patients with CD was observed both in the longitudinal and circular muscles. We conclude that VIP-IR and SP-IR are distributed widely in the mucosa, submucosa, and in the circular muscle in normal colon. VIP-IR is decreased in UC and CD, whereas SP-IR is increased in both, but more so in CD.