Comparative evaluation of nickel discharge from brackets in artificial saliva at different time intervals.

OBJECTIVES: To determine and compare the potential difference of nickel release from three different orthodontic brackets, in different artificial pH, in different time intervals. MATERIALS AND METHODS: Twenty-seven samples of three different orthodontic brackets were selected and grouped as 1, 2, and 3. Each group was divided into three subgroups depending on the type of orthodontic brackets, salivary pH and the time interval. The Nickel release from each subgroup were analyzed by using inductively coupled plasma-Atomic Emission Spectrophotometer (Perkin Elmer, Optima 2100 DV, USA) model. Quantitative analysis of nickel was performed three times, and the mean value was used as result. ANOVA (F-test) was used to test the significant difference among the groups at 0.05 level of significance (P < 0.05). The descriptive method of statistics was used to calculate the mean, standard deviation, minimum and maximum. SPSS 18 software ((SPSS.Ltd, Quarry bay, Hong Kong, PASW-statistics 18) was used to analyze the study. RESULT: The analysis shows a significant difference between three groups. The study shows that the nickel releases from the recycled stainless steel brackets have the highest at all 4.2 pH except in 120 h. CONCLUSION: The study result shows that the nickel release from the recycled stainless steel brackets is highest. Metal slot ceramic bracket release significantly less nickel. So, recycled stainless steel brackets should not be used for nickel allergic patients. Metal slot ceramic brackets are advisable.

Ghost teeth: Regional odontodysplasia of maxillary first molar associated with eruption disorders in a 10-year-old girl.

Regional odontodysplasia (RO) is an uncommon, developmental anomaly of the dental hard tissues that affects ectodermal and mesodermal dental components with characteristic clinical and radiographic findings. Clinically, RO affects a particular segment in either or both dentitions in the maxilla or mandible or both jaws. Radiographic features have consistently demonstrated thin and defective layers of enamel and dentine, resulting in a faint, fuzzy outline, creating a ghost-like appearance. The RO etiology is uncertain; numerous factors have been suggested and considered as local trauma, irradiation, hypophosphatasia, hypocalcemia, hyperpyrexia. A case of RO in a 10-year-old girl whose chief complaint were forwardly placed upper front teeth and the absence of eruption of permanent teeth. Clinical and radiographic features are described.

Estimation of alkaline phosphatase in the gingival crevicular fluid during orthodontic tooth movement in premolar extraction cases to predict therapeutic progression.

OBJECTIVES: The objective was to estimate the level of alkaline phosphatase (ALP) in gingival crevicular fluid (GCF) during en-masse retraction stage of orthodontic tooth movement. MATERIALS AND METHODS: 10 patients in the age group of 15-20 years participated in this study. GCF was sampled from the distal surface of the canine and mesial surface of the second premolar on day 0, 1, 7, 14, 21, and 28 postorthodontic treatment. RESULTS: A marked fall in the level of ALP was evident following force application. A progressive decreasing trend in ALP activity on both distal aspect of canine and mesial aspect of the second premolar was observed. The fall in ALP was more on distal aspect canine when compared to the mesial aspect of the second premolar. CONCLUSIONS: Measure of ALP activity in GCF could be an indicator of the biochemical and cellular alterations in bone turnover and hence rate the amount of tooth movement following orthodontic force application.

Prevalence of recurrent aphthous ulceration in the Indian Population.

OBJECTIVE: Patients with an oral ulcer may present initially to a general physician or a dental practitioner. Majority of the ulcers are benign and resolve spontaneously but small proportions are malignant. The aim of the present study was to determine the prevalence of recurrent aphthous ulcerations in the Indian population. MATERIAL AND METHODS: 3244 patients attending the Department of Oral Medicine and Radiology during the period from November, 2010 to December, 2012 with various complaints were examined. Of the patients examined 1669 were females and 1575 were males. RESULTS: 705 patients presented with recurrent aphthous ulceration (21.7%). Females (56.3%) were more commonly affected than males (43.7%). Patients in the third and fourth decade were most commonly affected. Stress was the most common factor associated with recurrent aphthous stomatitis (386 patients). 54.5% patients did not take any medications and 72.9% patients opined that the condition needed no dental consultation. CONCLUSION: The results of the present study indicate that recurrent aphthous ulceration is a common mucosal disorder in the Indian population. The early and proper diagnosis of the ulcers will help the dental practitioner in providing information to the patient regarding awareness and management of the condition. Key words:Recurrent aphthous ulcers, prevalence, Indian population.

Comparison of shear bond strength of resin reinforced chemical cure glass ionomer, conventional chemical cure glass ionomer and chemical cure composite resin in direct bonding systems: an in vitro study.

The acid pretreatment and use of composite resins as the bonding medium has disadvantages like scratching and loss of surface enamel, decalcification, etc. To overcome disadvantages of composite resins, glass ionomers and its modifications are being used for bonding. The study was conducted to evaluate the efficiency of resin reinforced glass ionomer as a direct bonding system with conventional glass ionomer cement and composite resin. The study showed that shear bond strength of composite resin has the higher value than both resin reinforced glass ionomer and conventional glass ionomer cement in both 1 and 24 hours duration and it increased from 1 to 24 hours in all groups. The shear bond strength of resin reinforced glass ionomer cement was higher than the conventional glass ionomer cement in both 1 and 24 hours duration. Conditioning with polyacrylic acid improved the bond strength of resin reinforced glass ionomer cement significantly but not statistically significant in the case of conventional glass ionomer cement.

Solid-state vs water-perfused catheters to measure colonic high-amplitude propagating contractions.

BACKGROUND: Solid-state (SS) manometry catheters with portable data loggers offer many potential advantages over traditional water-perfused (WP) systems, such as prolonged recordings in a more physiologic ambulatory setting and the lack of risk for water overload. The use of SS catheters has not been evaluated in comparison with perfused catheters in children. This study aims to compare data provided by SS and WP catheters in children undergoing colonic manometry studies. METHODS: A SS catheter and a WP catheter were taped together such that their corresponding sensors were at the same location. Simultaneous recordings were obtained using the SS and WP catheters (both 8 channels, 10 cm apart) in 15 children with severe defecation disorders referred for colonic manometry. Signals were recorded for a minimum of 1 h during fasting, 1 h after ingestion of a meal, and 1 h after the administration of bisacodyl. Solid-state signals from the data logger were analyzed against the perfused signals. All high-amplitude propagated contractions (HAPCs), the most recognizable and interpreted colonic motor event, were evaluated for spatial and temporal features including their durations, amplitudes, and propagation velocities. KEY RESULTS: A total of 107 HAPCs were detected with SS and 91 with WP catheters. All WP-HAPC were also observed with SS. Linear regression analysis showed that SS catheters tended to give higher readings in the presence of amplitudes <102 mmHg and lower reading with amplitudes >102 mmHg. An opposite trend was found for the duration of contractions. No significant difference was found for HAPC velocity. CONCLUSIONS & INFERENCES: SS catheters are more sensitive in recording HAPCs in children with defecation disorders compared with the more traditional WP assembly. There is a difference in measurements of amplitude between the two systems. Solid-state catheters offer potential advantages over WP catheters in children, being portable, safer to use, and may provide data over a more prolonged period.

Intrabiliary rupture of hydatid cyst: diagnosis with MRI and hepatobiliary isotope study.

Intrabiliary rupture is the most common complication of hepatic hydatid cyst yet it is unusual, occurring in only 3-17% of cases. The diagnosis is rarely difficult on ultrasound and CT when typical radiological features are present. In rare cases of complete evacuation, when characteristic findings of hydatid cyst are absent or when there is no evidence of the previous existence of liver hydatid cyst, the diagnosis may be difficult. In difficult cases, MRI, MRCP, ERCP and (99)Tc(m)-mebrofenin hepatobiliary scintigraphy are employed. We present a rare case of surgical obstructive jaundice due to rupture of a liver hydatid cyst into the biliary tract and gall bladder, with complete evacuation of its contents leading to misdiagnosis on CT and ultrasound. MRCP and (99)Tc(m)-mebrofenin hepatobiliary scintigraphy were able to establish a firm pre-operative diagnosis.

Spectral investigations on melanterite mineral from France.

EPR, Optical and IR spectral studies on a naturally occurring mineral melanterite are carried out at room temperature. EPR studies indicate the presence of Cu(II) ion in tetragonally distorted octahedral site and hyperfine lines could not be resolved due to higher concentration of the paramagnetic impurity in the mineral. Optical absorption spectrum is a characteristic of Fe(II) and Cu(II) ions. Crystal field parameters are evaluated. IR spectrum confirms the presence of water and sulphate ions.

Nephroptosis: the Tc-99m glucoheptonate scan as a diagnostic method.

A 40-year-old man was examined because he was a potential "healthy" renal donor. However, the routine work-up before surgery revealed hypertension, although there was no family history of this condition. The patient was examined to exclude secondary causes of hypertension. Tc-99m glucoheptonate renal imaging showed nephroptosis of the right kidney when the patient was standing, and this may have been the cause of the hypertension.

Colonic motility in children with repaired imperforate anus.

Following surgical correction of imperforate anus, voluntary bowel control is frequently poor because of abnormal anorectal function. Using colonic manometry we investigated the role of colonic motility in the pathogenesis of fecal soiling in children following imperforate anus repair. Thirteen children with repaired imperforate anus and fecal soiling underwent motility testing 2-12 years after anoplasty. All had fecal incontinence unresponsive to conventional medical treatment. Colonic manometry was performed using water-perfused catheters. Anorectal manometry was undertaken in 10 patients. Motility study results, treatment and outcomes were compared. All patients had high-amplitude propagating contractions (HAPCs) with an average of 80% propagation into the neorectum. There was no correlation between HAPC number or morphology and any variable. Internal anal sphincter resting pressure was low in 6/10 patients. Relaxation of the internal anal sphincter was present in 6/10 children. Only 1 of 5 patients able to cooperate was capable of generating a normal maximal squeeze pressure. Therapeutic regimens were changed in 11 patients with clinical improvement in five. Fecal soiling in patients with repaired imperforate anus is a multifactorial problem including propagation of excessive numbers of HAPCs into the neorectum as well as internal anal sphincter dysfunction. Colonic manometry in conjunction with anorectal manometry aids in the understanding of the pathophysiology of fecal soiling and guides clinical management in children with repaired imperforate anus.

Bisacodyl and high-amplitude-propagating colonic contractions in children.

BACKGROUND: The purpose of these studies was to determine the suitability of bisacodyl for stimulating high-amplitude-propagating contractions in pediatric studies of colonic manometry. METHODS: Water-perfused manometry catheters were inserted into the right colon of children referred for evaluations related to defecation disorders. Colonic motility was measured in a 3-hour test session: an hour fasting, an hour after a meal, and 30 minutes after administration of a provocative agent. RESULTS: Bisacodyl was superior to edrophonium as a stimulant for inducing high-amplitude-propagating contractions. Bisacodyl-induced high-amplitude-propagating contractions were similar in amplitude, duration, propagation velocity, and sites of origin and extinction to naturally occurring high-amplitude-propagating contractions. The effect of intrarectal bisacodyl was similar to that of intracecal bisacodyl, except for a delay of 10 minutes in onset. Bisacodyl induced high-amplitude-propagating contractions in all 28 children (22 with spontaneous high-amplitude-propagating contractions) without evidence of neuromuscular disease and in 2 of 9 children with a colonic neuromuscular disorder and no spontaneous high-amplitude-propagating contractions. CONCLUSIONS: Bisacodyl-induced high-amplitude-propagating contractions were quantitatively and qualitatively similar to naturally occurring high-amplitude-propagating contractions. In selected cases, such as in children receiving total parenteral nutrition or restricted fluid intake, it may be possible to shorten diagnostic colonic manometry using bisacodyl rather than waiting for spontaneous high-amplitude-propagating contractions.

Is electrogastrography a substitute for manometric studies in children with functional gastrointestinal disorders?

We performed simultaneous fasting and fed antroduodenal manometry and EGG in 25 children with functional bowel disorders. Three patients (12%) had an uninterpretable EGG. The manometric studies showed severe neuropathy in six patients; milder neuropathic changes in five patients; postprandial hypomotility in one patient; myopathy in four patients, and normal motility in the remaining six patients. The percentage of tachygastria time (frequency > 3.5 cycles/min) was higher in the patiens with mild (44.1 +/- 15.8%) and severe (48 +/- 19.1%) neuropathy than in the patients with myopathy (20 +/- 16.2%, P < 0.05) or with normal motility (23 +/- 13.3%, P < 0.05). There was a considerable overlap in the percentage of tachygastria and total arrhythmia time among the different study groups. The ratio of post- to preprandial power was significantly higher (2.5 +/- 0.07) in children with normal motility than in the other patients groups. Every child with total arrhythmia time < 35% and a ratio of post- to preprandial power > 2.4 had normal manometry. In summary, EGG differentiated groups of children with normal manometry from others with neuropathic or myopathic changes, but in a minority of patients the study was not interpretable and there was overlap in EGG results between children with normal and abnormal manometry.

Role of spinal afferents and calcitonin gene-related peptide in the postoperative gastric ileus in anesthetized rats.

OBJECTIVE: The object of this study was to investigate the mechanisms of postoperative gastric ileus in an experimental model of abdominal surgery in anesthetized rats. SUMMARY BACKGROUND DATA: Sensory neurons partly mediate postoperative gastric ileus. Among other neuropeptides, sensory neurons contain calcitonin gene-related peptide (CGRP) and release CGRP in response to noxious stimulation. Because CGRP inhibits gastric motility, it was hypothesized that abdominal surgery stimulates sensory neurons, which then releases CGRP, thereby inhibiting gastric motility. METHODS: Postoperative ileus was induced by abdominal surgery. Gastric corpus motility was measured by an intragastric catheter. CGRP action was blocked by CGRP immunoneutralization or by a CGRP receptor antagonist. Spinal sensory neurons were ablated by application of a sensory neurotoxin (capsaicin) to the celiac and superior mesenteric ganglia. RESULTS: Abdominal surgery decreased gastric corpus motility in the first 5 minutes after abdominal surgery by 59 +/- 5% and by 24 +/- 4% during the 1st postoperative hour. Capsaicin pretreatment of the celiac and superior mesenteric ganglia, CGRP immunoneutralization, or CGRP receptor antagonism reversed the postoperative decrease in gastric corpus motility during the 1st postoperative hour by 50%, 100%, and 59%, respectively. CONCLUSIONS: These data indicate that spinal sensory neurons and CGRP partly mediate postoperative gastric ileus. CGRP may be released from spinal sensory neuron terminals in the celiac and superior mesenteric ganglia as part of an extraspinal intestinogastric inhibitory reflex activated by abdominal surgery.

Colonic manometry in children with chronic intestinal pseudo-obstruction.

Pressure changes were evaluated in the transverse, descending, and rectosigmoid colon of 30 children with chronic intestinal pseudo-obstruction. Twenty two had severe lifelong constipation and eight had symptoms suggesting a motility disorder exclusively of the upper gastrointestinal tract. Based on prior antroduodenal manometry, 24 children were diagnosed as having a neuropathic and six a myopathic form of intestinal pseudo-obstruction. On the day of study, endoscopy was used to place a manometry catheter into the transverse colon and intraluminal pressure was recorded for more than four hours. After a baseline recording, we gave a meal to assess the gastrocolonic response. Colonic contractions were noted in 24 children. The six children with no colonic contractions had a hollow visceral myopathy and constipation. In the children with colonic contractions, fasting motility did not differentiate children with and without constipation. After the meal, in all eight children without constipation there was (1) an increase in motility index (3.2 (SEM 0.3) mm Hg/min basal v 8.4 (SEM 1.1) mm Hg/min postprandial; p < 0.001), and (2) at least one high amplitude propagated contraction (HAPC). In the 16 constipated children with colonic contractions the motility index did not significantly increase after the meal (2.1 (SEM 0.3) mm Hg/min basal v 3.1 (SEM 0.4) mm Hg/min postprandial) and 12 of them had no HAPCs (p < 0.01 v group without constipation). In summary, in children with a clinical diagnosis of chronic intestinal pseudo-obstruction, constipation is associated with absence of HAPCs, and the gastrocolonic response or with total absence of colonic contractions. It is concluded that studies of colonic manometry are feasible in children and may document discrete abnormalities in those with intestinal pseudo-obstruction with colonic involvement.

Use of colonic manometry to differentiate causes of intractable constipation in children.

We evaluated colon manometry as a means of differentiating causes of intractable constipation in children. We studied pressure changes in the transverse, descending, and rectosigmoid colons of 23 children with intractable constipation. All patients had a history of less than one bowel movement per week for longer than 2 years without resolution after conventional medical management. The possibility of Hirschsprung disease was excluded in all. On the basis of pathologic and manometric studies of the upper gastrointestinal tract, 10 patients had a diagnosis of gastrointestinal neuropathy and two had a diagnosis of myopathy. The other 11 patients had functional fecal retention; this diagnosis was based on history and outcome of therapy. On the day of study we used endoscopy to place a manometry catheter into the transverse colon and recorded intraluminal pressure for longer than 4 hours. After obtaining a baseline recording, we gave the patient a meal to assess gastrocolonic response. Colonic contractions were recorded in 21 of 23 children. Children with functional fecal retention could be differentiated from those with neuropathy by examination of the postprandial record. After a meal children with functional fecal retention had (1) an increase in motility index (3.4 +/- 0.5 while fasting vs 9.1 +/- 1.3 postprandially; p less than 0.001), and (2) at least one high-amplitude propagated contraction (in 10 of 11 children). The patients with neuropathy had no high-amplitude propagated contractions (p less than 0.001 vs group with functional fecal retention) and motility index in these children did not increase significantly after a meal (2.7 +/- 1.0 while fasting vs 2.9 +/- 1.3 postprandially). The two children with hollow visceral myopathy had no contractions. We conclude that in children with severe chronic constipation the colonic results of manometry differentiate patients with functional fecal retention from those with neuropathy or myopathy of the colon.

An abnormal rate of actin myosin cross-bridge cycling in colonic smooth muscle associated with experimental colitis.

Previous studies showed that colonic smooth muscle develops less contractile force to neurohumoral stimulation when associated with mucosal inflammation. This study evaluated 1) the Ca2+ dependence for colonic smooth muscle contraction, 2) the maximum velocity of muscle shortening (Vmax), and 3) changes in 20-kDa myosin light-chain (MLC) phosphorylation in distal circular colonic muscle from healthy rabbits and from rabbits with experimental colitis, induced by Formalin and immune complexes. The isometric tension of unskinned muscle stimulated with bethanechol or KCl was less (P less than 0.05) in animals with colitis compared with the control group. In saponin-skinned muscle, the amplitude of the maximal tension at [Ca2+] of 3 x 10(-7) M was decreased (P less than 0.05) in colitis animals (4.3 +/- 0.9 x 10(4) N/m2, n = 7) compared with healthy animals (10.5 +/- 2.4 x 10(4) N/m2, n = 6). However, the ED50 for Ca2+ stimulation was similar (P greater than 0.05) in both groups. When MLC was thiophosphorylated with ATP gamma S, the tension development was decreased in colitis (2.1 +/- 0.3 x 10(4) N/m2, n = 5; P less than 0.01) compared with normals (5.0 +/- 1.4 x 10(4) N/m2, n = 5). In healthy animals, phosphorylation of 20-kDa MLC increased rapidly to 51.2 +/- 3.1% within 15 s after stimulation and subsequently declined to 19.0 +/- 2.1% at 5 min. Vmax was maximal (0.14 Lo/s) 13 s after stimulation and declined before maximal active isometric stress. In colitis animals, the 20-kDa MLC phosphorylation (P less than 0.05) and the Vmax (P less than 0.01) were decreased.(ABSTRACT TRUNCATED AT 250 WORDS)

Cisapride in children with chronic intestinal pseudoobstruction. An acute, double-blind, crossover, placebo-controlled trial.

To assess the effect of cisapride on gastrointestinal motility and gastric emptying in children with chronic intestinal pseudoobstruction, 20 children (mean age, 4.9 years; 14 female and 6 male) who required special means of alimentation or who had severe symptoms confirmed by diary during 2 weeks before the study were studied. A motility catheter with recording sites in the antrum and duodenum was placed on the first day of the study and remained in place until the end of the 5-day study. Cisapride (0.3 mg/kg PO t.i.d.) or placebo was given in double-blind randomized crossover fashion, with a 2-day "washout" interval. Antroduodenal motility was recorded on days 2 and 5. Recording consisted of 4 hours of fasting and 2 hours after a complex liquid meal labeled with 99mTc. Gastric emptying was assessed for 1 hour after the meal. Based on manometry, 16 patients had neuropathic and 4 patients had myopathic disorders. Cisapride had no effect on the discrete, qualitative abnormalities found in individual records. Cisapride increased the postprandial duodenal motility index from 1180 +/- 256 mm Hg/30 min after placebo to 2385 +/- 430 mm Hg/30 min (P less than 0.05) but had no significant effect on the antral motility index. Cisapride did not alter the profound delay in gastric emptying; time to reach 50% of initial activity (T1/2) was 105 +/- 20 vs. 93 +/- 19 minutes and percentage of retention after 60 minutes (R60) 56% +/- 4% vs. 58% +/- 4% in control vs. cisapride, respectively. In summary, in children with chronic intestinal pseudoobstruction, cisapride increased postprandial duodenal motility but did not improve gastric emptying.

Colonic motility and transit in health and ulcerative colitis.

Preprandial and postprandial colonic motility and transit (scintigraphy), with respect to the splenic flexure, were studied in 10 patients with ulcerative colitis and in 9 healthy subjects. The healthy subjects had a postprandial increase in intraluminal pressure that was significantly (P less than 0.03) greater in the descending colon than in other regions of the colon. In ulcerative colitis, the pressure was decreased in all regions compared with healthy subjects, with no significant pressure gradient among different regions. In normal subjects, transit was quiescent during fasting; eating stimulated both antegrade and retrograde transit. In ulcerative colitis, transit was variable before as well as after the meal. Both healthy subjects and patients with ulcerative colitis had more rapid emptying from the splenic flexure into the sigmoid than into the transverse colon. More frequent, low-amplitude, postprandial propagating contractions occurred in ulcerative colitis (P less than 0.05) than in healthy subjects. Propagating contractions were always antegrade and caused a rapid movement of the tracer into the sigmoid. In conclusion, ulcerative colitis is characterized by (a) decreased contractility, (b) increased low-amplitude propagating contractions, and (c) variable transit. These disturbances may accentuate the diarrhea in ulcerative colitis.

Effect of eating on colonic motility and transit in patients with functional diarrhea. Simultaneous scintigraphic and manometric evaluations.

The aim of this study was to correlate colonic motility with transit in 8 patients with functional diarrhea compared to 12 healthy subjects. Intraluminal pressure was measured with perfused catheter ports in the transverse colon, splenic flexure, and descending and sigmoid colons. Transit of the luminal contents was measured by following the movement of 99mTC-diethylenetriaminepentaacetic acid instilled as a bolus in the splenic flexure. In patients with diarrhea, the intraluminal marker moved in and out of the transverse and sigmoid colon regions of interest during fasting, unlike healthy subjects, in whom the marker remained in the splenic flexure. After eating, radioactivity immediately increased in both the transverse and sigmoid colons in healthy subjects. In the patients with diarrhea, eating did not alter the marker movement into the different regions of the colon compared with fasting. Within 100 minutes of eating, the intraluminal marker almost disappeared from the regions of interest in patients with diarrhea. Postprandial colonic nonpropagating contractions increased in each region of the colon in healthy subjects; there was only a small postprandial increase in colonic motility in patients with diarrhea. However, the numbers of fasting and postprandial propagating contractions were increased in patients with diarrhea compared with healthy subjects (P less than 0.02). Each propagating contraction moved more tracer in patients with diarrhea than in healthy subjects (P less than 0.05). These studies suggest that (a) in patients with diarrhea, the fluctuation of marker in both transverse and sigmoid colons during the fasting and postprandial periods is associated with decreased nonsegmenting contractions and frequent propagating contractions; and (b) in healthy subjects, the intraluminal marker moved after eating because of a pressure gradient caused by nonpropagating contractions.

Capsaicin-sensitive vagal afferents contribute to gastric acid and vascular responses to intracisternal TRH analog.

Central injection of TRH or its stable analog, RX77368, produces a vagal cholinergic stimulation of gastric acid secretion, mucosal blood flow and motor function. In the present study, we have investigated the contribution of capsaicin-sensitive vagal afferent fibers to the gastric responses to intracisternal injection of RX77368. Gastric acid secretion, measured in acute gastric fistula rats anesthetized with urethane, in response to intracisternal injection of RX77368 (3-30 ng) was reduced by 21-65% by perineural pretreatment of the vagus nerves with capsaicin 10-20 days before experiments. The increase in gastric mucosal blood flow measured by hydrogen gas clearance induced by intracisternal injection of RX77368 (30 ng) was also reduced by 65% in capsaicin-pretreated rats. In contrast, increases in gastric motor function measured manometrically or release of gastric luminal serotonin in response to intracisternal injection of RX77368 (3-30 ng) were unaltered by capsaicin pretreatment. The mechanism by which vagal afferent fibers contribute to the secretory and blood flow responses to the stable TRH analog is unclear at present, but it is possible that the decrease in gastric mucosal blood flow by lesion of capsaicin-sensitive vagal afferents limits the secretory response.