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Biomedical subjects

M G Sarr

Publications and source records attributed to M G Sarr.

At least 109 records · Page 6Linked to original sources

Effect of extrinsic denervation in a canine model of jejunoileal autotransplantation on mechanical and electrical activity of jejunal circular smooth muscle.

Little is known about the acute and chronic effects of the intestinal transplantation on smooth muscle contractile physiology. Our aim was to determine the effects of the denervation necessitated by jejunoileal autotransplantation on membrane potential and contractile activity. Six dogs underwent a model of jejunoileal autotransplantation that specifically avoids ischemia/reperfusion injury (by maintaining blood flow to the gut during the "transplantation" procedure). Strips of jejunal circular muscle were studied sequentially before and 2 and 8 weeks after denervation by recording mechanical and intracellular electrical activities in vitro. The amplitude of spontaneous contractions (X +/- SD) was increased (P < 0.05) at 2 compared to 0 weeks (126 +/- 19 vs 77 +/- 32 g/g; P < 0.05) but markedly decreased at 8 weeks (7 +/- 2 g/g). Contraction frequency, resting membrane potential, and amplitude of slow waves were unchanged across these time points. Bethanechol (10(-7)-10(-4) M) and substance P (10(-8)-10(-6) M) dose-dependently increased contractile activity at all time points, but the absolute change in amplitude was decreased at 8 weeks. The amplitude of inhibitory junction potentials (IJPs) and duration of inhibition of contractile activity in the presence of cholinergic and adrenergic blockade increased at 2 and 8 weeks; off-contraction amplitude was decreased at 8 weeks (P < 0.05). These effects may occur via changes in neurotransmitter release, changes in regulation of membrane receptors, or alteration of characteristics of the membrane threshold potential.

Animals↗

Bacterial lipase and high-fat diets in canine exocrine pancreatic insufficiency: a new therapy of steatorrhea?

BACKGROUND & AIMS: Nutrients and properties of lipases affect survival of lipolytic activity during aboral gastrointestinal transit. Whether different doses and formulations of bacterial lipase and diets affect steatorrhea was tested in pancreatic-insufficient dogs. METHODS: A dose of 0-600,000 IU of powdered and 135,000 and 300,000 IU of liquid bacterial lipase was given with a standard meal to 5 dogs with ligated pancreatic ducts. In 4 dogs, 0 or 300,000 IU (normal 6-hour postprandial amount) of powder bacterial lipase was also given with five meals containing 850 kcal with different nutrient caloric densities (mixture design). Coefficients of fat absorption during 72-hour fecal balance studies were used to assess treatments. RESULTS: With the standard meal, powder bacterial lipase reduced steatorrhea in a dose-dependent manner (P = 0.03), and 135,000 and 300,000 IU of the liquid form decreased steatorrhea more than powder bacterial lipase (P = 0.017 and 0.057, respectively). Coefficients of fat absorption with 300,000 IU of powder bacterial lipase correlated (r2 = 0.79; P < 0.001) with increasing proportions of fat calories in diets. CONCLUSIONS: Liquid bacterial lipase decreases steatorrhea more than powder, and 300,000 IU of powder bacterial lipase ingested with high-fat meals corrects canine pancreatic steatorrhea. The combination of adequate mixing of small amounts (milligrams) of bacterial lipase and high-fat meals abolishes canine steatorrhea and may abolish human pancreatic steatorrhea.

Animals↗

Role of extrinsic innervation in carbohydrate-induced ileal modulation of pancreatic secretion and upper gut function.

Previously we showed that carbohydrate (CHO) in the ileum slowed gastric emptying and increased pancreatic amylase secretion relative to that of other enzymes. Our aim here was to determine if extrinsic innervation of the jejunoileum participates in the CHO-induced ileal modulation of postprandial upper gut function. Six dogs were studied before and 2-3 weeks after in situ neural isolation of the jejunoileum (complete extrinsic denervation). Gastric emptying (GE) and pancreatic amylase secretion were quantitated for 4 h after a 300-ml meal containing 3H-PEH (liquid marker) and 99mTc sulfur colloid cooked with eggs (solid marker). Coincident with feeding, we started a distal ileal infusion of 150 mM NaCl or 40 mg.min-1 CHO. Extrinsic denervation abolished the slowing of GE of liquids and solids and the augmented increase in amylase and trypsin in relation to solid emptying seen in the neurally intact dogs prior to denervation. Denervation also abolished the decrease in total pancreatic exocrine secretion in response to ileal CHO. Increases in plasma concentrations of peptide YY (PYY) were correlated temporally with decreased GE of solids and increased exocrine secretion during ileal CHO in neurally intact dogs, but no increases in PYY release occurred after extrinsic denervation. Extrinsic denervation of the jejunoileum abolished the effect of ileal CHO on GE of liquids and solids, the decrease in total amylase secretion during ileal CHO, and the relative increase in enzyme secretion expressed as total enzyme output per percentage solid marker emptied. Extrinsic innervation of the jejunoileum mediates ileal modulation of GE and the relationship of amylase secretion to GE of solids. The mechanism of this effect may be via neurally mediated release of PYY.

Amylases↗

ERCP-induced acute necrotizing pancreatitis: is it a more severe disease?

Acute necrotizing pancreatitis (ANP) is an uncommon but serious complication of endoscopic retrograde cholangiopancreatography (ERCP). This study compares the severity, clinical course, and long-term outcome of ERCP-induced ANP with ANP induced by other causes. A review of 72 consecutive patients with ANP treated surgically at the Mayo Clinic identified ERCP as the cause in 6 patients (8%). Compared to the remaining 66 patients, the post-ERCP group had higher APACHE II scores on admission (mean, 13 vs. 10) and more extensive pancreatic necrosis (mean, 55 vs. 47%). The post-ERCP group had a higher rate of infected necrosis (100 vs. 75%) and required earlier necrosectomy after the onset of pancreatitis (9 vs. 13 days). The rate of postoperative pancreatic and enteric fistulae was also higher (50 vs. 33%). Although the mortality rate in the post-ERCP group was lower (17 vs. 29%), they were significantly younger (50 vs. 62 years; p = 0.02) and all the survivors had residual long-term morbidity. ANP is more severe when ERCP-induced; infection introduced during the ERCP may, in part, account for this severity.

Adult↗

Motilin and OHM-11526 activate a calcium current in human and canine jejunal circular smooth muscle.

Motilin is a potent agonist for gastrointestinal smooth muscle contraction and has been proposed to regulate the onset of phase III of the migrating motor complex in dogs and humans. The effects of motilin and OHM-11526, a motilin antagonist in rabbit smooth muscle strips, were examined in isolated canine and human jejunal circular smooth muscle cells using whole cell patch-clamp techniques with Ba2+ as the charge carrier. Effects of both drugs on inward current through L-type Ca2+ channels (ICaL) in both canine and human cells were first observed at 10(-3) M. At 10(-6) M, motilin increased ICaL in canine and human jejunal circular smooth muscle cells by 43 +/- 20 and 45 +/- 11%, respectively, and OHM-11526 increased ICaL by 54 +/- 8 and 54 +/- 14%, respectively. The increase in inward current was blocked by nifedipine and by guanosine 5'-O-(2-thiodiphosphate) but not by pertussis toxin. Washout of both drugs resulted in a further increase in ICaL. These data suggest that both motilin and OHM-11526 activate and ICaL in human and canine jejunal circular smooth muscle cells through a G protein-coupled mechanism.

Animals↗

Surgical treatment of obesity: who is an appropriate candidate?

The increasing prevalence and far-reaching medical, social, and economical implications of obesity have made it a national health-care crisis in the United States. About one in every three persons is at least 20% above "ideal" body weight, and approximately 5% have direct weight-related serious health problems (morbid obesity), including hypertension, hyperlipidemia, coronary artery disease, adult-onset diabetes mellitus, degenerative osteoarthropathy, and obstructive sleep apnea. Morbidly obese patients have an estimated 6- to 12-fold increase in mortality. In addition, they have a substantially diminished quality of life, not only physically but also psychosocially due to overt and occult prejudice. Weight reduction must be aggressively pursued in these patients. Medically supervised weight-control programs have been ineffective because patients cannot maintain pronounced long-term weight loss. In contrast, current operative methods have been proved to be effective in helping patients achieve and maintain permanent weight reduction. Several operations have been designed and assessed; with these procedures, weight loss is achieved by inducing malabsorption, maldigestion, early satiety, or a combination of these outcomes. Although these operations have associated side effects and limitations, the expected benefits outweigh the risks. For optimal results, patients must be carefully selected and treated by a multidisciplinary group.

Gastroplasty↗

SDZ HTF 919 stimulates canine colonic motility and transit in vivo.

Effects of the nonbenzamide 5-hydroxytryptamine4 agonist SDZ HTF 919 on gastrointestinal motility are unclear. Our aim was to assess the in vivo effects on gastrointestinal and colonic transit of radiolabeled residue and on colonic phasic contractility. In six female dogs, transit was measured over a period of 2 days by radioscintigraphy and colonic motility was measured by pneumohydraulic perfusion manometry of the proximal and distal colon. SDZ HTF 919 was administered initially by bolus i.v. infusion, followed by s.c. injection 8 and 16 hr later. Doses tested were 0.03, 0.1 and 0.3 mg/kg, and isotonic saline and vehicle served as controls in each dog. Stomach and small bowel transit was not significantly altered by SDZ HTF 919. Overall, i.v. SDZ HTF 919 accelerated colonic transit during the first 1 hr, compared with controls. These effects were significant even with the lowest dose of SDZ HTF 919. Responses to higher infusion doses were more variable. SDZ HTF 919 did not cause significant changes in quantitative pressure indices, such as amplitude or motor index, in the small bowel or colon. Prolonged postprandial colonic contractions, each lasting >30 sec, were noted after each i.v. agent and were significantly more frequent with the 0.03 mg/kg dose than with control (vehicle) treatment. Thus, SDZ HTF 919 accelerates canine colonic transit in vivo during the first 1 hr after i.v. administration. SDZ HTF 919 appears to be a promising agent for stimulation of mammalian colonic transit.

Animals↗

Surgical aspects of patients with adenocarcinoma of the stomach operated on for cure.

BACKGROUND: A retrospective study was performed to evaluate our recent results of curative gastric resections for adenocarcinoma. METHODS: Between 1979 and 1988, 187 patients fulfilled study entry criteria. This group of patients composes 64% of all patients with tumors arising distal to the gastroesophageal junction. Tumors arising in the region of the gastroesophageal junction were excluded. Patients were classified according to the American Society of Anesthesiologists physical status classification ( > or = 3, 56%) and Eastern Cooperative Oncology Group performance status ( > or = 2, 44%). Histologic characteristics were re-reviewed. INTERVENTIONS: Subtotal and total gastrectomies were performed in 78% and 22% of the patients, respectively. Extended lymph node dissections were performed selectively (5%). Adjuvant chemotherapy and radiotherapy were employed in 3% and 2% of patients, respectively. RESULTS: Postoperative morbidity and mortality were 27% and 4%, respectively. Synchronous splenectomy (P = .06) and type of gastric resection (P = .06) showed a borderline association with postoperative complications, but did not affect postoperative mortality. With a median follow-up time of 47 months in all patients, and a median of 9 years in patients still alive, the 5- and 10-year overall survival rates (Kaplan-Meier method) were 48% and 32%, respectively. In univariate survival analysis, age, American Society of Anesthesiologists classification, stage, tumor diameter, serosal extension of tumor lymph node metastases, and type of resection showed prognostic significance. In the Cox multivariate analysis, however, only serosal extension of tumor (P < .001) and lymph node metastases (P = .02) were independent prognostic factors. CONCLUSIONS: Despite the older age and comorbid conditions of patients with gastric cancer, 5-year survival was achieved in half the patients by standard radical operations. Until appropriate controlled prospective studies are performed, total gastrectomy, splenectomy, and extended lymph node dissection should not be routinely adopted, given their unproven efficacy and potentially increased morbidity and mortality.

Adenocarcinoma↗

Neural isolation of the jejunoileum. Effect on tissue morphometry, mucosal disaccharidase activity, and tissue peptide content.

The aim of this study was to determine the effects of a model of intestinal extrinsic denervation on mucosal structure and function. Six dogs underwent in situ neural isolation of the jejunoileum (Group 2); six other dogs served as operated controls (Group 1), and five nonoperated dogs were naive controls (Group 3). Thirty-centimeter segments of proximal jejunum and distal ileum were excised before (time zero) and at 2 weeks and 8 weeks postoperatively in Groups 1 and 2, while similar regions were removed at time zero in Group 3. Tissues were analyzed for morphology with quantitative morphometry, mucosal disaccharidase activities (sucrase, maltase, and lactase), and tissue content of selected regulatory peptides in transmural, mucosa/submucosa, and muscularis regions. In situ neural isolation had no significant or consistent effects on morphology/morphometry or on mucosal disaccharidase activities. Tissue content of neuropeptide Y decreased markedly (P < 0.002) in all layers of the jejunal and ileal walls, but tissue content of vasoactive inhibitory polypeptide, substance P, cholecystokinin, neurotensin, met-enkephalin, neurokinin A, somatostatin, and calcitonin gene-related peptide demonstrated only minor changes. The physiologic effects of intestinal transplantation (extrinsic denervation and disruption of intrinsic, enteric neural continuity, and lymphatic drainage) have little effect on morphology, mucosal disaccharidase activity, and tissue content of most regulatory peptides. How these minor alterations might affect enteric function, however, needs to be investigated.

Animals↗

Jejunoileal transplantation. Effects on characteristics of canine jejunal motor activity in vivo.

This study was designed to determine if extrinsic innervation and intrinsic neural continuity with the duodenum (neuroenteric physiologic pathways disrupted during intestinal transplantation) modulate the characteristics of interdigestive motor activity in the canine small bowel. Five dogs served as neurally intact controls (group 1) and 10 dogs (group 2) underwent a model of jejunal autotransplantation involving in situ neural isolation of the jejunoileum. Fasting duodenal and jejunal motor activity was recorded on-line to a microcomputer using closely spaced duodenal and jejunal manometry catheters. Characteristics of global motor patterns, the migrating motor complex (MMC), and local motor patterns, including individual contractions and grouped clustered contractions, were determined. Neural isolation of the jejunoileum disrupted coordination of duodenal and jejunal phase III activity, increased the variability of cycling of the MMC, decreased the period of the jejunal MMC, and increased motility indices in the neurally isolated jejunum. In contrast, single pressure waves and clustered contractions in the neurally isolated jejunum were not altered significantly in incidence or direction, distance, or velocity of spread. In situ neural isolation of the jejunoileum leads to temporal dissociation of the MMC between the transplanted segment (jejunum) and the duodenum but does not appear to alter markedly the characteristics of local contractile activity as measured by individual or grouped contractions. The occurrence of interdigestive jejunal motor patterns and the local organization of individual and grouped small intestinal contractions are not controlled by extrinsic innervation or intrinsic neural continuity with the duodenum.

Animals↗

Alterations in carrier-mediated glutamine transport after a model of canine jejunal autotransplantation.

The effects of small bowel transplantation (SBTx) on absorptive function are unknown. Preliminary experiments showed a decrease in absorption of glutamine. Our aim was to determine mechanisms of decreased ileal transport of glutamine utilizing a model of intestinal autotransplantation. Seven dogs were studied before and after a model of jejunoileal autotransplantation. In vivo absorption experiments were performed before and two and eight weeks postoperatively with an electrolyte solution containing glutamine (20 mM). In vitro glutamine transport was studied using brush-border membrane vesicles (BBMV) prepared from ileal mucosa obtained from six other dogs and compared to a controls. In vivo net absorptive flux of glutamine decreased at two weeks but returned toward baseline by eight weeks (P = 0.06). Transport of glutamine into BBMVs was decreased at two weeks and remained decreased at eight weeks. KmaxNa+, a measure of carrier affinity was unchanged but VmaxNa+, a function of the number of transporter was decreased at two and eight weeks. Glucose transport was unchanged. It is concluded that jejunoileal autotransplantation decreases ileal absorption of glutamine by a decrease in carrier-mediated transport of glutamine.

Alanine↗

Contractile properties of enteric smooth muscle after small bowel transplantation in rats.

BACKGROUND: The effects of small bowel transplantation (SBTx) on the function of enteric smooth muscle are not understood. PURPOSE: To study the contractile properties of enteric smooth muscle after SBTx in rats. METHODS: Five groups of inbred Lewis rats (n > or = 8 each group) were studied: unoperated, naive controls; operated controls 1 week (OC1) and 8 weeks after intestinal transection/reanastomosis of the proximal jejunum and distal ileum; and 1 week (TX1) and 8 weeks (TX8) after syngeneic orthotopic SBTx. Contractile activity of circular muscle strips of jejunum was evaluated in tissue chambers. Spontaneous contractile activity (force per wet weight tissue) increased in TX1, TX8, and OC1 rats (P < or = 0.01). Frequency of contractions doubled in OC1 rats (P < or = 0.001) but was unchanged in the other groups. In the presence of nonadrenergic noncholinergic (NANC) blockade, spontaneous contractile activity increased in TX1 and OC1 (P < or = 0.005) without a change in frequency of contractions. Inhibition of neural activity with tetrodotoxoin increased amplitude and frequency in all groups. Bethanechol (3 x 10(-6) to 3 x 10(-4) mol/L) increased, and norepinephrine (1 x 10(-6) to 1 x 10(-4) mol/L) dose-dependently decreased the amplitude and frequency of contractions in all groups; equi-effective concentrations, however, did not differ among groups. CONCLUSIONS: The increase in contractile activity after intestinal transection/reanastomosis is secondary to an increase in frequency of contractions and not amplitude. SBTx increases contractile amplitude of circular muscle due, in part, to downregulation of NANC nerves but not via muscarinic or adrenergic hypersensitivity. These alterations in enteric physiology of intestinal contractile activity may have important implications in clinical SBTx.

Animals↗

Repair of complex giant or recurrent ventral hernias by using tension-free intraparietal prosthetic mesh (Stoppa technique): lessons learned from our initial experience (fifty patients).

BACKGROUND: Giant complex ventral hernias are difficult to repair, and recurrent rates are high (greater than 10%). Our aim was to review our experience with a modified Stoppa technique. METHODS: From 1991 to 1995, 50 patients underwent repair with a large panel of prosthetic mesh placed intraparietally posterior to rectus muscle but anterior to posterior rectus sheath; 27 had undergone one to five previous hernia repairs, and 14 patients had a simultaneous intraabdominal procedure. Mean follow-up (100%) has been 24 months. RESULTS: No operative deaths occurred. Hospital morbidity included four wound infections, 2 of which were serious and required mesh removal; both occurred in patients in whom the gut was opened for other simultaneous intraabdominal procedures. Late morbidity included two delayed wound infections/limited mesh infections managed by office debridement and open packing, three seromas, and transient abdominal wall pain in seven patients. Long-term follow-up showed no recurrent hernias in the 48 patients without early serious mesh infections requiring mesh removal; thus the long-term success rate was 96% (48 of 50 patients). CONCLUSIONS: Recurrent rates after this modified Stoppa repair of giant complex giant ventral hernias are very low. Early or late mesh infection occurred in four patients. Tension-free prosthetic mesh repair offers a marked improvement in outcome. Because of the possibility of mesh infection, simultaneous, contaminated, or even clean-contaminated intraperitoneal procedures should be avoided if possible.

Abdominal Muscles↗

Intraductal papillary-mucinous tumors of the pancreas: clinicopathologic features, outcome, and nomenclature. Members of the Pancreas Clinic, and Pancreatic Surgeons of Mayo Clinic.

BACKGROUND & AIMS: Intraductal papillary-mucinous tumor (IPMT) of the pancreatic ducts is increasingly recognized. This study investigated if clinical, imaging, or, histological features predicated outcome, formulated a treatment algorithm, and clarified relationships among IPMT, mucinous cystic neoplasms of the pancreas (MCN), and chronic pancreatitis. METHODS: The medical records, radiographs, and pathological specimens of 15 patients with IPMT (dilated main pancreatic duct or branch ducts with mucin overproduction) who were evaluated between October 1983 and January 1994 were reviewed. RESULTS: One patient had hepatic metastases. Fourteen underwent an operation (6 distal pancreatectomy, 4 total pancreatectomy, and 4 pancreaticoduodenectomy); all had dysplastic intraductal epithelium and chronic pancreatitis, whereas 3 had invasive adenocarcinoma. After a median of 25 months, 10 patients were alive; 3 of 4 with malignant and 2 of 11 with benign IPMT died (P < 0.05). Patients with or without carcinoma had similar clinical and radiographic features. A clinical diagnosis of chronic pancreatitis had been made in 9 patients with benign IMPT and in none with malignant IPMT (P < 0.05). CONCLUSIONS: IPMT is a dysplastic and likely precancerous lesion that is frequently diagnosed as chronic pancreatitis and is separate from MCN. Because it is not possible to distinguish noninvasive from invasive IPMT preoperatively, complete surgical excision of the dysplastic process is our treatment of choice whenever appropriate.

Aged↗

Proximal gastric vagotomy. Comparison between open and laparoscopic methods in the canine model.

OBJECTIVE: The authors compared open and laparoscopic proximal gastric vagotomies for efficacy of acid reduction and preservation of gastric emptying. SUMMARY BACKGROUND DATA: Laparoscopic methods have been used to perform vagotomy in patients with duodenal ulcer; however, no direct comparisons are available of laparoscopic and open surgical procedures regarding acid reduction and gastric emptying. METHODS: Thirty-one consecutive dogs were randomized to open proximal gastric vagotomy (OPGV; n = 11), laparoscopic anterior seromyotomy and posterior truncal vagotomy (ASPTV; n = 10), or laparoscopic proximal gastric vagotomy (LPGV; n = 10). Intraoperative endoscopic Congo red testing assured complete vagotomy. Basal acid output (BAO) and maximal acid output (MAO) during pentagastrin and insulin-induced hypoglycemia were measured with marker dilution techniques, and gastric emptying was assessed with radionuclide-labelled solid and liquid markers before and 5 weeks after operation. RESULTS: Operative time (mean +/- standard error of the mean) for OPGV was shorter compared with ASPTV and LPGV (86 +/- 7 minutes vs. 124 +/- 7 minutes and 115 +/- 7 minutes; p < 0.002). Postoperative BAO did not decrease in any group. Open proximal gastric vagotomy and LPGV, but not ASPTV, decreased MAO (p < 0.05); (after pentagastrin, OPGV from 26.4 +/- 1.7 mEq/hour to 11.3 +/- 0.1 mEq/hour, LPGV from 21.4 +/- 1.0 mEq/hour to 6.4 +/- 0.5 mEq/hour; after insulin-induced hypoglycemia, OPGV from 9.9 +/- 0.5 mEq/hour to 2.2 +/- 0.3 mEq/hour, LPGV from 7.9 +/- 0.5 mEq/hour to 1.9 +/- 0.4 mEq/hour). Gastric emptying of liquids and solids, as quantitated by the time for one half of the marker to empty (T 1/2) and the shape of the emptying curve, were similar before and after all three surgical procedures. CONCLUSIONS: Laparoscopic proximal gastric vagotomy was comparable to OPGV in decreasing stimulated gastric acid production without significantly altering gastric emptying. Anterior seromyotomy and posterior truncal vagotomy was less effective in decreasing MAO and required more operative time. Laparoscopic proximal gastric vagotomy has the potential to become accepted therapy for patients with duodenal ulcer managed presently with OPGV.

Animals↗

Intraabdominal hemorrhage complicating surgical management of necrotizing pancreatitis.

Surgical management of necrotizing pancreatitis (NP) may result in significant intraabdominal hemorrhage requiring intervention. To determine the incidence and management of hemorrhage complicating operative management of NP, we analyzed retrospectively all patients undergoing operative treatment of NP between 1985 and 1994. Thirteen of 61 patients (21%) developed intraabdominal hemorrhage requiring intervention. The five patients (38%) who experienced more than one bleeding episode had undergone more prior operative debridements (mean of 5.6 vs. 3.8), had had higher transfusion requirements during the first bleeding episode (mean of 27.4 vs. 11.3 U of packed red blood cells), and had a higher hospital mortality (60 vs. 38%) compared to patients with only one bleeding episode. Coexistence of pancreatic and/or gastrointestinal fistula was more common in patients who developed bleeding (36 vs. 11%). Seventeen bleeding sites (eight venous, seven arterial, two generalized oozing) were identified. Angiography was successful in one of two patients in whom it was employed. Surgical control was effective in the other 12 patients. There was no acute mortality related to hemorrhage, but the hospital mortality was greater than in those without hemorrhage (46 vs. 21%). We conclude that significant hemorrhage complicates the surgical management of NP in approximately 20% of patients; while it can be effectively controlled surgically and does not lead to immediate mortality, it may predict worse prognosis.

Aged↗

Neural control of canine small intestinal motility during nonnutrient infusion.

Our aim was to determine the effect of in situ neural isolation of the jejunoileum (extrinsic denervation and disruption of enteric neural continuity with the duodenum) on the spread of single pressure waves (SPW) and clustered contractions (CC) in response to increasing rates of isolated duodenal and jejunoileal nonnutrient infusions. Ten dogs were prepared with duodenal and jejunal infusion and manometry catheters and a diverting proximal jejunal cannula. Five of the dogs also underwent in situ neural isolation of the entire jejuno- ileum A noncaloric solution was infused at 0-15 ml/min into proximal duodenum or jejunum while manometric data were collected. Alterations in direction, distance, and velocity of spread of SPW and CC with increasing rates of intestinal infusion were analyzed by linear regression of responses to increasing infusion rates. Neural isolation of the jejunoileum did not markedly alter characteristics of duodenal or jejunal SPW or CC under conditions of no intestinal infusion. After neural isolation of jejunoileum, increasing rates of jejunal infusion decreased both the proportion and distance of antegrade spread of SPW in duodenum. These findings suggest that extrinsic innervation to the jejunoileum and enteric neural continuity with the duodenum do not regulate jejunal SPW or CC. Increasing rates of nonnutrient intestinal infusions do not alter local motor patterns in the innervated or neurally isolated jejunum, but after neural isolation of the jejunoileum, these infusions do alter characteristics of duodenal SPW by mechanisms independent of neural pathways.

Animals↗