Metabolic dependence of the electromyogram of the cat colon

1980 ◽  
Vol 239 (3) ◽  
pp. G173-G176 ◽  
Author(s):  
S. Anuras ◽  
S. M. Chien ◽  
J. Christensen
Keyword(s):  
Slow Wave ◽  
Distal Colon ◽  
Proximal Colon ◽  
Wave Frequency ◽  
Reduced Frequency ◽  
Metabolic Dependence ◽  
Spike Bursts

Strips of colon muscle (1 x 10 cm) were exposed to alterations of temperature, to 2,4-dinitrophenol, and were deprived of O2. Cooling reduced slow-wave frequency in proximal colon from 5.2 at 37 degrees C to 3.9, 2.7, 1.2 and 0.5 cycle/min at 34, 30, 25, and 20 degrees C, respectively; all changes were significant (P < 0.05). Heating also reduced slow-wave frequency in proximal colon from 5.2 at 37 degrees C to 5.1, 4.8 (P < 0.05), and 3.3 (P < 0.05) cycle/min at 39, 41, and 43 degrees C, respectively. Hypoxia reduced slow-wave frequency from 4.6 at 95% O2 to 2.8 cycle/min at 0% O2 (P < 0.05). 2,4-Dinitrophenol (10(-4) M) reduced frequency from 5.3 to 2.7 cycle/min (P < 0.05). The results of studies of distal colon were similar. In distal colon cooling reduced the time occupied by migrating spike bursts from 20.7% at 37 degrees C to 11.1% at 25 degrees C, and 7.9% at 20 degrees C (P < 0.05). Hypoxia also reduced the time occupied by migrating spike bursts from 16.7% at 95% O2 to 5.9% at 0% O2 (P < 0.05).

Effects of alterations in calcium levels on cat small intestinal slow waves

1982 ◽  
Vol 243 (1) ◽  
pp. C7-C13 ◽  
Author(s):  
A. W. Mangel ◽  
J. A. Connor ◽  
C. L. Prosser
Keyword(s):  
Intracellular Calcium ◽  
Slow Wave ◽  
Calcium Concentration ◽  
Longitudinal Muscle ◽  
Slow Waves ◽  
Wave Frequency ◽  
Intracellular Calcium Concentration ◽  
Magnesium Concentration ◽  
Reduced Frequency ◽  
Intestinal Slow Waves

Intact segments of cat intestinal muscle and strips of isolated longitudinal muscle were treated with agents that reduce intracellular calcium concentration: incubation in 0-calcium saline, treatment with calcium conductance blockers, elevated extracellular magnesium concentration, or alkalinization with NH4Cl. These treatments reduced amplitude and frequency of slow waves in intact segments but only reduced frequency in isolated longitudinal muscle. The reduction in frequency was characterized by prolongation of the hyperpolarized phase of the slow waves. Treatments that would moderately increase intracellular calcium concentration, i.e., increasing external calcium to four times normal levels or lowering pH by CO2, increased slow-wave frequency. Increased frequency was associated with reduced amplitude and shortening of the hyperpolarized phase of the slow waves. Greater than four times normal calcium levels and intense spiking reduced slow-wave frequency. Chlorotetracycline fluorescence, an indicator of intracellular calcium concentration, showed fluctuations synchronous with slow waves. It is concluded that the reactions that pace the generation of slow waves are dependent on the level of intracellular calcium.

Origin of migrating myoelectric complex in sheep.

1977 ◽  
Vol 233 (6) ◽  
pp. E483
Author(s):  
Y Ruckebusch ◽  
L Bueno
Keyword(s):  
Electrical Activity ◽  
Slow Wave ◽  
Duodenal Bulb ◽  
Wave Frequency ◽  
Proximal Jejunum ◽  
Implanted Electrodes ◽  
Migrating Myoelectric Complex ◽  
The Mean ◽  
Conscious Sheep ◽  
Spike Bursts

The electrical activity of the gastroduodenal junction was recorded in conscious sheep for 8 to 12 wk with chronically implanted electrodes. The flow of digesta was simultaneously recorded, and the duodenal bulb was isolated at the time of implantation. The mean slow-wave frequency of the antrum was 5.6 +/- 0.3/min with spike bursts randomly superimposed on about 60% of the slow waves. The activity of the duodenal bulb was characterized by an absence of slow-wave unpropagated spike bursts and by two types of propagated spike bursts. The first consisted of isolated bursts accompanied by a rapid movement of digesta through the entire duodenum and proximal jejunum. The second, an irregular series of 8-12 spike bursts was associated with total evacuation of the duodenal bulb, followed in turn by an inhibition of antral spiking activity and the development of a migrating myoelectric complex (MMC) in the distal duodenum. The results indicate that in sheep organization of the MMC is located at the duodenal level where the duodenal bulb has a reservoir function.

Effect of deoxycholic acid on colonic motility in the rabbit

1980 ◽  
Vol 238 (4) ◽  
pp. G321-G325 ◽  
Author(s):  
W. J. Snape ◽  
S. Shiff ◽  
S. Cohen
Keyword(s):  
Smooth Muscle ◽  
Slow Wave ◽  
Deoxycholic Acid ◽  
Contractile Activity ◽  
Colonic Motility ◽  
Proximal Colon ◽  
Wave Frequency ◽  
Myoelectrical Activity ◽  
Circular Smooth Muscle ◽  
Serosal Surface

The purpose of the study was to determine the effect of the bile salt, deoxycholic acid, on colonic myoelectrical and contractile activity recorded from a loop of proximal colon in the anesthetized rabbit. Myoelectrical activity was recorded from bipolar electrodes attached to the serosal surface of the proximal colon. Contractile activity of the circular smooth muscle was measured with a strain gauge attached in the circular direction on the serosal surface of the colonic loop. The colonic slow wave frequency was 12.5 +/- 1.1 cycles/min. The slow wave frequency throughout the loop was homogeneous with a low coefficient of variation of the slow wave frequency (5.8 +/- 0.3). There were spike potentials superimposed on 78.1 +/- 3.4% of the slow waves. The addition of 8 or 16 mM deoxycholic acid did not change the slow wave or spike activity. However, deoxycholic acid stimulated a dose-dependent increase in migrating action potential complexes. These complexes were associated with a forceful contraction of the circular smooth muscle that propelled luminal contents in the direction of the burst. Deoxycholic acid also stimulated an increase in luminal fluid content.

scholarly journals The Relationship between Inflammation Markers (CRP, IL-6, sCD40L) and Colorectal Cancer Stage, Grade, Size and Location

Diagnostics ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1382
Author(s):  
Olga Martyna Koper-Lenkiewicz ◽  
Violetta Dymicka-Piekarska ◽  
Anna Justyna Milewska ◽  
Justyna Zińczuk ◽  
Joanna Kamińska
Keyword(s):  
Colorectal Cancer ◽  
Linear Regression ◽  
Tumor Size ◽  
Distal Colon ◽  
Proximal Colon ◽  
Model Parameters ◽  
Grade Group ◽  
Who Grade ◽  
The Mean ◽  
Mean Concentration

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.

scholarly journals Long-term effectiveness of faecal immunochemical test screening for proximal and distal colorectal cancers

Gut ◽  
2021 ◽  
pp. gutjnl-2020-322545
Author(s):  
Han-Mo Chiu ◽  
Grace Hsiao-Hsuan Jen ◽  
Ying-Wei Wang ◽  
Jean Ching-Yuan Fann ◽  
Chen-Yang Hsu ◽  
...  
Keyword(s):  
Large Scale ◽  
Distal Colon ◽  
Population Based ◽  
Proximal Colon ◽  
Advanced Stage ◽  
Site Specific ◽  
Faecal Immunochemical Test ◽  
Immunochemical Test ◽  
Selection Factors

ObjectiveTo measure the effects of faecal immunochemical test (FIT) for colorectal cancer (CRC) screening on overall and site-specific long-term effectiveness of population-based organised service screening.DesignA prospective cohort study of Taiwanese nationwide biennial FIT screening was performed. A total of 5 417 699 eligible subjects were invited to attend screening from 2004 through 2009 and were followed up until 2014. We estimated the adjusted relative rates (aRRs) on the effectiveness of reducing advanced-stage CRC (stage II+) and CRC death by Bayesian Poisson regression models with the full adjustment for a cascade of self-selection factors (including the screening rate and the colonoscopy rate) and the completeness of colonoscopy together with demographic features.ResultsFIT screening (exposed vs unexposed) reduced the incidence of advanced-stage CRC (48.4 vs 75.7 per 100 000) and mortality (20.3 vs 41.3 per 100 000). Statistically significant reductions of both incidence of advanced-stage CRCs (aRR=0.66, 95% CI 0.63 to 0.70) and deaths from CRC (aRR=0.60, 95% CI 0.57 to 0.64) were noted. FIT screening was more effective in reducing distal advanced-stage CRCs (aRR=0.61, 95% CI 0.58 to 0.64) and CRC mortality (aRR=0.56, 95% CI 0.53 to 0.69) than proximal advanced CRCs (aRR=0.84, 95% CI 0.77 to 0.92) and CRC mortality (aRR=0.72, 95% CI 0.66 to 0.80).ConclusionA large-scale population-based biennial FIT screening demonstrates 34% significant reduction of advanced-stage CRCs and 40% reduction of death from CRC with larger long-term effectiveness in the distal colon than the proximal colon. Our findings provide a strong and consistent evidence-based policy for supporting a sustainable population-based FIT organised service screening worldwide. The disparity of site-specific long-term effectiveness also provides an insight into the remedy for lower effectiveness of FIT screening in the proximal colon.

scholarly journals Long range synchronization within the enteric nervous system underlies propulsion along the large intestine in mice

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Nick J. Spencer ◽  
Lee Travis ◽  
Lukasz Wiklendt ◽  
Marcello Costa ◽  
Timothy J. Hibberd ◽  
...  
Keyword(s):  
Nervous System ◽  
Smooth Muscle ◽  
Enteric Nervous System ◽  
Lymphatic Vessels ◽  
Distal Colon ◽  
Distal Region ◽  
Proximal Colon ◽  
Synchronous Firing ◽  
Electrophysiological Recordings ◽  
Intrinsic Neurons

AbstractHow the Enteric Nervous System (ENS) coordinates propulsion of content along the gastrointestinal (GI)-tract has been a major unresolved issue. We reveal a mechanism that explains how ENS activity underlies propulsion of content along the colon. We used a recently developed high-resolution video imaging approach with concurrent electrophysiological recordings from smooth muscle, during fluid propulsion. Recordings showed pulsatile firing of excitatory and inhibitory neuromuscular inputs not only in proximal colon, but also distal colon, long before the propagating contraction invades the distal region. During propulsion, wavelet analysis revealed increased coherence at ~2 Hz over large distances between the proximal and distal regions. Therefore, during propulsion, synchronous firing of descending inhibitory nerve pathways over long ranges aborally acts to suppress smooth muscle from contracting, counteracting the excitatory nerve pathways over this same region of colon. This delays muscle contraction downstream, ahead of the advancing contraction. The mechanism identified is more complex than expected and vastly different from fluid propulsion along other hollow smooth muscle organs; like lymphatic vessels, portal vein, or ureters, that evolved without intrinsic neurons.

Microradiographic Anatomy of the Explanted Rat Colon

1995 ◽  
Vol 36 (2) ◽  
pp. 210-214 ◽  
Author(s):  
F. Pomerri ◽  
G. Gasparini ◽  
A. Martin ◽  
W. Fries ◽  
E. Pagiaro ◽  
...  
Keyword(s):  
Distal Colon ◽  
Proximal Colon ◽  
Rat Colon ◽  
Sprague Dawley ◽  
Double Contrast ◽  
Colonic Wall ◽  
Sprague Dawley Rats ◽  
Contrast Technique ◽  
Isolated Aorta ◽  
Mucosal Folds

The colon of 32 healthy Sprague-Dawley rats was studied microradiographically. The colonic arterial distribution of 18 rats was examined after injecting barium sulfate into the isolated aorta. The mucosal surface in 9 rats was studied using double-contrast technique after colon explantation. In 5 animals arterial and mucosal studies were carried out simultaneously. The radiographic thickness of the colonic wall was measured using a comparative microscope. The specimens were observed, photographed and examined histologically. Unlike the cecum and distal colon which, when insufflated, do not have mucosal folds, the proximal colon exhibits folds in an oblique direction corresponding to that of the arteries, and the colonic wall in this region is thicker. Comparison between arterial and mucosal microradiographic anatomy and wall thickness enables the proposition of a simple nontopographic division of the rat colon into cecum, proximal colon and distal colon.

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