Colonic formation of soft feces in rabbits: a role for endogenous prostaglandins

1986 ◽  
Vol 250 (3) ◽  
pp. G302-G308
Author(s):  
M. Pairet ◽  
T. Bouyssou ◽  
Y. Ruckebusch

Rabbits produce hard and soft feces in a circadian rhythm. The motor activity of the haustrated proximal colon is inhibited during the formation of soft feces, whereas the spiking activity of the distal colon is stimulated. A potential role for endogenous prostaglandins (PG) in the control of the soft-feces elaboration by the rabbit colon was investigated in conscious animals by using PGE2 and PGF2 alpha and by inhibiting them with indomethacin. The infusion of both PGE2 and PGF2 alpha induced typical electromechanical events consisting of inhibition of the proximal and stimulation of the distal colon and was followed by soft-pellet defecation. Rabbits accustomed to be fed twice daily produced soft feces at fixed intervals of 252 +/- 32 min after the evening meal, with a soft-to-hard feces ratio of 1.45. After indomethacin treatment, this ratio was significantly (P less than 0.01) reduced to 0.92. These results are consistent with the concept that endogenous prostaglandins play a major role in the motor function involved in soft-feces formation by the rabbit.

1991 ◽  
Vol 260 (4) ◽  
pp. G646-G652 ◽  
Author(s):  
M. Dapoigny ◽  
S. K. Sarna

We investigated the effect of physical exercise on colonic motor activity in the fasted and fed states in six conscious dogs. Each dog was implanted with nine strain gauge transducers: three on the proximal, three on the middle, and three on the distal colon. The dogs ran for 1 h on a treadmill at 5 km/h (slope 5%). In the fasted state, the dogs exercised during the 5th h of recording after an overnight fast, and in the fed state during the 1st, 3rd, and 5th postprandial hour. In the fasted state, exercise significantly decreased the frequency of colonic migrating motor complexes (MMCs) but had no effect on the total or the mean duration of contractile states in the proximal, middle, and distal colon. Postprandially, exercise disrupted colonic MMCs and replaced them with nonmigrating motor complexes in all three periods of exercise (1st, 3rd, and 6th h). Exercise also increased the total duration per hour of contractile activity throughout the colon during the 1st and 3rd h and only in the distal colon during the 6th h after the meal. The dogs never defecated during rest in the fasted or the fed state. Shortly after the start of exercise in the fasted and fed states, giant migrating contractions (GMCs) occurred, and they were followed by defecation. In approximately 40% of the experiments, another GMC originated in the proximal colon, approximately 10 min after the first defecation, and migrated caudad up to the middle colon. These GMCs were not associated with defecation but caused mass movements.(ABSTRACT TRUNCATED AT 250 WORDS)


1992 ◽  
Vol 262 (1) ◽  
pp. G62-G68 ◽  
Author(s):  
S. K. Sarna

We investigated the effect of absorbable and nonabsorbable fluid perfusion and cleansing on colonic motor activity in eight intact conscious dogs. Each dog was instrumented with an indwelling catheter in the proximal colon and seven strain gauge transducers on the entire colon. After an overnight fast, a control recording was made for 3 h, followed by 3 h of perfusion and 3 additional h of postperfusion recording. Next day, a 3-h recording was made when the colon was empty. The colon exhibited normal migrating and nonmigrating motor complexes in the control uncleansed state. The perfusion of absorbable electrolyte or nonabsorbable Colyte solution immediately disrupted the migrating motor complexes and replaced them with almost continuous but irregular contractions at all recording sites. Both solutions significantly prolonged the mean and total duration per hour of contractile states in the proximal, middle, and distal colon. The dogs began to leak fluid stools in squirts approximately 40-80 min after the start of perfusion. This type of incontinence was not associated with any specific type of motor activity. Infrequently, giant migrating contractions occurred during perfusion and caused explosive diarrhea. The migrating motor complexes remained disrupted during the 3-h postperfusion period. However, on the next day, the empty colon exhibited normal migrating motor complexes. The frequency of giant migrating contractions during perfusion and in the empty colon was significantly greater than that in the normal uncleansed colon. The total duration per hour of colonic motor activity in the empty colon was also greater than that in the normal uncleansed colon. We conclude that excessive fluid in the colon significantly alters its motor pattern.(ABSTRACT TRUNCATED AT 250 WORDS)


2001 ◽  
Vol 280 (4) ◽  
pp. G546-G554 ◽  
Author(s):  
Asensio Gonzalez ◽  
Sushil K. Sarna

The aim of this study was to investigate the modulation of in vitro rat colonic circular muscle contractions by dextran sodium sulfate (DSS)-induced inflammation and in spontaneous inflammation in HLA-B27 rats. We also examined the potential role of hydrogen peroxide (H2O2) in modulating excitation-contraction coupling. The muscle strips from the middle colon generated spontaneous phasic contractions and giant contractions (GCs), the proximal colon strips generated primarily phasic contractions, and the distal colon strips were mostly quiescent. The spontaneous phasic contractions and GCs were not affected by inflammation, but the response to ACh was suppressed in DSS-treated rats and in HLA-B27 rats. H2O2production was increased in the muscularis of the inflamed colon. Incubation of colonic muscle strips with H2O2suppressed the spontaneous phasic contractions and concentration and time dependently reduced the response to ACh; in the middle colon, it also increased the frequency of GCs. We conclude that H2O2mimics the suppression of the contractile response to ACh in inflammation. H2O2also selectively suppresses phasic contractions and increases the frequency of GCs, as found previously in inflamed dog and human colons.


2021 ◽  
Vol 8 ◽  
Author(s):  
Akihito Nakajima ◽  
Tomoyoshi Shibuya ◽  
Takashi Sasaki ◽  
Yu Jie Lu ◽  
Dai Ishikawa ◽  
...  

Nicotine affects the gastrointestinal environment and modulates ulcerative colitis (UC). However, the associations among nicotine, gut metabolites, and UC are still largely unknown. We investigated whether orally administered nicotine affected gut metabolites and dextran sodium sulfate (DSS)-induced colitis. C57BL/6 male mice were orally administered nicotine solution in drinking water prior to inducing DSS-induced colitis. Short-chain fatty acids (SCFAs) and indole in gut contents and fecal samples were measured by GC-MS and hydroxylamine-based indole assays, respectively. Oral administration of nicotine increased indole concentration in feces, but, in contrast, SCFA values did not differ with nicotine administration. Indole levels were increased in the distal colon and rectum but not in the cecum and proximal colon. DSS-induced colitis was less severe clinically and histological changes were minimal in the rectum of orally nicotine-administered mice compared to mice drinking only water. 16S rRNA microbiome on the feces revealed an increasing in Clostridium and Porphyromonas in nicotine-administered mice. In conclusion, nicotine administration was associated with increased indole levels in the distal colon and rectum and attenuated DSS-induced colitis. Oral administration of nicotine may play a potential role in indole upregulation and prevention of UC.


1984 ◽  
Vol 246 (5) ◽  
pp. G603-G610 ◽  
Author(s):  
J. H. Sellin ◽  
R. DeSoignie

Rabbit proximal colon (PC), examined in vitro, exhibits transport characteristics distinct from distal colon. Unlike distal colon, PC does not demonstrate amiloride-inhibitable electrogenic Na absorption. Additionally, neither amphotericin nor "stimulatory" anions induce Na absorption in PC. Electrical measurements and radioisotopic flux studies under short-circuit conditions indicate that PC is a moderately leaky epithelium with a conductance (9.0 +/- 0.2 mS) midway between ileum and distal colon; under basal conditions PC has Na and Cl transport rates near zero, and 5.5 microM epinephrine (Epi) stimulates electrically silent Na-Cl coupled absorption. The mechanism of this cotransport was investigated further: Cl substitution with either sulfate or gluconate did not substantially alter Epi-enhanced Na absorption. The Epi stimulation of Cl absorption in a Na-free solution was diminished. Amiloride, 10(-3) M, inhibited Epi-enhanced Na absorption by approximately 50%. The effects of cAMP-mediated (theophylline or 8-bromo-cAMP) and Ca-mediated (ionophore A23187) secretory stimuli were examined. In the basal state, none of these agents had a consistent effect on ion transport. However, after stimulation of Na and Cl absorption by Epi, both of the cAMP-related secretagogues had a marked antiabsorptive effect on Na and Cl transport. The antiabsorptive effects of Ca ionophore A23187 were less marked. These results suggest that rabbit proximal colon a) does not share the transport properties characteristic of distal colon, b) possesses an Epi-sensitive, Na-Cl-coupled absorptive pathway, and c) responds to secretory stimuli in an antiabsorptive manner rather than by electrogenic secretion.


1998 ◽  
Vol 274 (3) ◽  
pp. G459-G464 ◽  
Author(s):  
Pauline Jouet ◽  
Benoît Coffin ◽  
Marc Lémann ◽  
Caroline Gorbatchef ◽  
Claire Franchisseur ◽  
...  

In healthy humans, meals stimulate phasic and tonic motor activity in the unprepared distal colon. The response of the proximal colon remains unknown. In this study, we assessed the effect of a liquid meal on proximal and distal colonic motor activity. In 12 healthy volunteers, colonic tone and phasic motility were simultaneously recorded by using an electronic barostat and perfused catheters in the fasting state and in response to a 1,000-kcal meal. The meal significantly increased the phasic activity in the distal colon (230 ± 46% of the basal value; P = 0.02) but not in the proximal colon (138 ± 25% of the basal value; P = 0.2). The intrabag volume of the barostat was significantly more reduced in the distal than in the proximal colon (74 ± 11 vs. 50 ± 9% of the basal values, respectively; P = 0.04). We conclude that the postprandial response of the unprepared proximal colon is an immediate tonic contraction that is less pronounced than in the distal colon.


2001 ◽  
Vol 120 (5) ◽  
pp. A173-A174
Author(s):  
F BASCHIERA ◽  
C BLANDIZZI ◽  
M FOMAI ◽  
M TACCA

Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1382
Author(s):  
Olga Martyna Koper-Lenkiewicz ◽  
Violetta Dymicka-Piekarska ◽  
Anna Justyna Milewska ◽  
Justyna Zińczuk ◽  
Joanna Kamińska

The aim of the study was the evaluation whether in primary colorectal cancer (CRC) patients (n = 55): age, sex, TNM classification results, WHO grade, tumor location (proximal colon, distal colon, rectum), tumor size, platelet count (PLT), mean platelet volume (MPV), mean platelet component (MCP), levels of carcinoembryonic antigen (CEA), cancer antigen (CA 19-9), as well as soluble lectin adhesion molecules (L-, E-, and P-selectins) may influence circulating inflammatory biomarkers: IL-6, CRP, and sCD40L. We found that CRP concentration evaluation in routine clinical practice may have an advantage as a prognostic biomarker in CRC patients, as this protein the most comprehensively reflects clinicopathological features of the tumor. Univariate linear regression analysis revealed that in CRC patients: (1) with an increase in PLT by 10 × 103/μL, the mean concentration of CRP increases by 3.4%; (2) with an increase in CA 19-9 of 1 U/mL, the mean concentration of CRP increases by 0.7%; (3) with the WHO 2 grade, the mean CRP concentration increases 3.631 times relative to the WHO 1 grade group; (4) with the WHO 3 grade, the mean CRP concentration increases by 4.916 times relative to the WHO 1 grade group; (5) with metastases (T1-4N+M+) the mean CRP concentration increases 4.183 times compared to non-metastatic patients (T1-4N0M0); (6) with a tumor located in the proximal colon, the mean concentration of CRP increases 2.175 times compared to a tumor located in the distal colon; (7) in patients with tumor size > 3 cm, the CRP concentration is about 2 times higher than in patients with tumor size ≤ 3 cm. In the multivariate linear regression model, the variables that influence the mean CRP value in CRC patients included: WHO grade and tumor localization. R2 for the created model equals 0.50, which indicates that this model explains 50% of the variance in the dependent variable. In CRC subjects: (1) with the WHO 2 grade, the mean CRP concentration rises 3.924 times relative to the WHO 1 grade; (2) with the WHO 3 grade, the mean CRP concentration increases 4.721 times in relation to the WHO 1 grade; (3) with a tumor located in the rectum, the mean CRP concentration rises 2.139 times compared to a tumor located in the distal colon; (4) with a tumor located in the proximal colon, the mean concentration of CRP increases 1.998 times compared to the tumor located in the distal colon; if other model parameters are fixed.


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