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Mechanisms of progesterone induced gallbladder hypomotility in guinea pigs
April 1995
Motility and Nerve-Gut Interactions
DISSOCIATIONOF LOWER ESOPHAGEAL SPHINCTER AND CRURAL DIAPHRAGM RESPONSE TO A PHARYNGEAL STIMULUS, C. Chiareli, R. K. M#tal , R. Shaker, J Liu. From the Dept. of Med., University of Virginia HSC, Ch. ville, Virginia, 22908. Background: Intrapharyngeal injection of minute amounts of water causes lower esophageal sphincter (LES) relaxation which can last 45 sees or longer. A long duration LES relaxation is the hallmark of transient LES relaxation (TLESR) which is the major mechanism of gastroesophageal reflux (GER). We studied 5 normal healthy subjects to determine if the LES relaxation caused by stimulation of the pharynx is accompnied by inhibtion of the crural diaphragrrl, esophageal common cavity and GER, some Of the other characterstics of TLESR. METHODS: The following parameters were measured: LES and crural diaphragm pressures using a reverse perfused Sleeve, crural diaphragm EMG activity, esophageal pH, 5 cms above the LES. Water was injected into the pharynx in the increasing volumes of .05, 0.1, 0.2, 0.3mi. Slow continous water injections in the pharynx (3ml\mint> induced LES relaxation was als0 studied. RESULTS: The LES relaxed in response to as little as .05 ml of rapid pharyngeal Water injection and maximal LES relaxation was seen at 0.2 to 0.3ral. The threshold for slow injection was 0.7 ml, higher than rapid injection. The duration of LES relaxation for rapid injection ranged from 4-80seconds ( mean = 30 sees). In contrast to LES, rapid as well as slow injection caused an increase of Crural diaphragm (CD) contraction during periods of LES relaxation. Response of LES and CD to different pharyngeal bolus volumes ' 0.05 ml LES Pressure -17+8%
0.1 ml
0.2 ml
0.3 ml
-43_+9%:
-59_+5%
-71_+6%
,
CD Pressure +7+28% +14_+7% +17_+16% +14_+11% l'here were no episodes of acid reflux or commoncavity during any of pharyngeal stimulated LES relaxations. CONCLUSIONS:Our data suggest that the characterstics of LES relaxation induced by pharyngeal water stimulation resemble only partly with TLESR.
DUODENOGASTROESOPHAGEAL REFLUX- EVALUATION OF SIMULTANEOUS AMBULATORY ESOPHAGEAL PH AND BILIRUBIN MONITORING. M.G. Choi, S.H. Park, J.Y. Han, I.S. Chung, K.W. Chung, H.S. Sun, D.H. Park. Dept. of Internal Medicine, Catholic University Medical College, Seoul, Korea Background/Aims: Esophageal reflux damage may be produced by agents other than acid and the term "alkaline esophagitis' has been applied. Esophageal pH monitoring to assess duodenogastroesophageal reflux has been suggested but gastric neutralization has made these methods difficult to prove conclusively. To investigate the role of duodenogastroesophageal reflux in GERD, we performed simultaneous esophageal pH and bilirubin monitoring(Bilitec 2000, Synetics Medical, Sweden) in 14 symptomatic Korean patients with gastroesophageal reflux and 12 healthy controls. Abnormal reflux was defined when the percent total time of pH < 4 or bilirubin absorbance > 0.14 exceeded the 95th percentile of the range obtained in healthy volunteers. Results: (1) Abnormal gastroesophageal reflux was diagnosed in 11(78.6%) of 14 patients, who could be categorized into acid refluxers(36.4%), bile refluxers(9.1%) or combined acid and bile refluxers(54.5%). (2) All 6 patients with severe esophagifis (>grade 2) were combined refluxers and had markedly prolonged bile reflux compared to 8 patients with normal or miJd esophagitis(percent total time of bilirubin absorbance > 0.14 (mean+-SE): 30.3+-6.9% vs 10.9+-4.5%, P<0.05). (3) Mean pH of esophageal refluxate during bile reflux episode lasting longer than 5 minutes was 6.0(9.3% for pH <4, 8.8% for pH 4-5, 26.6% for pH 6-7, 47% for pH 6-7 and 8.3% for pH >7). (4) 8 patients with a symptom index greater than 25% experienced 24 reflux symptoms of which 12(50.0%) were associated with acid reflux, 5(20.8%) were associated with bile reflux and 7(29.2%) were not associated with bile or acid reflux. Conclusions: (1) Alkaline esophageal reflux is a misnomer. Esophageal pH monitoring does not adequately identify symptomatic non-acidic duodenogastroesophageal reflux. (2) Patients with combined acid and bite reflux are more likely to develop severe esophagitis.
A583
• MECHANISMS OF PROGESTERONE INDUCED GALLBLADDER HYPOMOTILITY IN GUINEA PIGS. V. Chitnavis, P. Yu, O. Chen. P. Biancani and J. Behar. Department of Medicine, Rhode Island Hospital and Brown University School of Medicine. Providence, R.I. Adult male guinea pigs were used to study the mechanisms by which progesterone impairs gallbladder muscle contractility. Animals received either daily subcutaneous injections of progesterone (2 mg/kg for 7 days) or placebo. Gallbladder muscle cells were isolated by enzymatic digestion with collagenase and permeabilized with saponin as needed. Contraction was express as % shortening with respect to untreated cells. Contraction in response to CCK (10-13 M to 10-7 M) was significantly reduced in animals treated with progesterone (maximal shortening of 115+1% at 10-8 M CCK) when compared to control animals (20-+1%, P<0.05). However, the dose-dependent contractions caused by KC1, which is receptor-G protein independent, were not significantly different (Anova) in these two groups of animals. Contraction in response to direct G-protein activation with GTlh,S and aluminum fluoride (A1F) was. similarly reduced in muscle cells from the progesterone treated animals. GTPTS at 10-4 M caused a maximal shortening of 11+1% as opposed to 22+1% in controls. A1F caused a maximal shortening of 13+1% and 20i-1% in progesterone-treated and control animals, respectively (P<0.01). In contrast, IP3 (10-11 M to 10-5M) contracted the muscle cells in a dose dependent manner in the progesterone treated animals with a maximal contraction of 21+1% which is not different from controls. To further assess the function of G-proteins, we examined their GTP binding properties using 35S-labeled GTPtS (0.5 nM) in muscle membranes in the presence of 2 I/M GDP, 5 mM Mg2+, 100 mM Na+, 50 mM Tris, pH 7.5, 1 mM EDTA and 1 mM dithiothreitol. 35SGTP%,S binding reached a plateau at 40 min, which was chosen for subsequent experiments. The binding was suppressed by both GDP and unlabeled GTPyS in a concentration-dependent manner, suggesting that binding is specific. The binding was dose-dependently stimulated by CCK (10-11-10-6 M) in normal prairie dogs, with a maximal increase of 73_+16% from basal level at 10-8 M of CCK. CCK-induced stimulation was significantly suppressed in progesterone treated animals with a maximal increase of 21+7% from basal level at 10-8 M of CCK. In conclusion, progesterone may impair gallbladder muscle contractility by affecting G proteins.
ELECTROGASTROGRAPHIC FINDINGS IN CYCLIC VOMITING SYNDROME (CVS). S.K.F. Chonq, T. Nowak, M. Goddard, J. Flueckiger, J.M. Croffie, J.F. Fitzgerald. Depts. of Pediatric Gastroenterology and Nutrition and Adult Gastroenterology, Indiana University School of Medicine, Indianapolis, IN Cyclic vomiting syndrome is characterized by repeated, prolonged episodes of severe vomiting in childhood, usually starting suddenly and lasting from hours to days (commonly 1-4 days). It is of unknown etiology and the intensity of the vomiting spell can lead to dehydration. No treatment has been effective to prevent the attacks, but anti-migraine medication has been u s e d . We have studied 8 children (5 female, 3 male), ages 4-13 years, who presented from J u n e 1 9 9 3 to Dec 1994 with intractable symptoms occurring once every 2 to 6 weeks and compared the electrogastrography (EGG) to 3 normal control children (siblings) and 3 disease controls (H. pylori gastritis, recurrent abdominal pain). The healthy normal children were aged 5-12 years. Five of the eight children were on treatment with propranolol, cisapride or metoclopramide. Two hours after a light breakfast, each subject lay supine and four bipolar electrodes were placed at equidistant loci on the upper abdomen. The electrodes were situated parallel to the longitudinal axis of the stomach. Recordings were obtained for 60 minutes before and after ingestion of a light meal. Pre- and postprandial signals were digitized at 1 Hz and subjected to autoregressive spectral analysis. Six children presented with episodes of taehygastria during the acute illness. All subjects showed a predominant 3 cpm rhythm. However, the patients with CVS showed evidence of tachygastria during the acute symptoms. Three of the 6 showed episodes of tachygastria (4-6 cpm) after eating. The tracing of 4-6 cpm Occurred at an average duration of 1-3 minutes during the recordings. EGG abnormalities are seen in children with CVS. The changes are transient and are best diagnosed during an acute episode. Tachygastria is the most frequent abnormality seen during a 2 hour monitoring. Further studies should be performed over a longer time (24-hour recordings) period at home where attacks frequently occur in order to predict the timing of episodes and to plan management.
Motility and Nerve-Gut Interactions
DISSOCIATIONOF LOWER ESOPHAGEAL SPHINCTER AND CRURAL DIAPHRAGM RESPONSE TO A PHARYNGEAL STIMULUS, C. Chiareli, R. K. M#tal , R. Shaker, J Liu. From the Dept. of Med., University of Virginia HSC, Ch. ville, Virginia, 22908. Background: Intrapharyngeal injection of minute amounts of water causes lower esophageal sphincter (LES) relaxation which can last 45 sees or longer. A long duration LES relaxation is the hallmark of transient LES relaxation (TLESR) which is the major mechanism of gastroesophageal reflux (GER). We studied 5 normal healthy subjects to determine if the LES relaxation caused by stimulation of the pharynx is accompnied by inhibtion of the crural diaphragrrl, esophageal common cavity and GER, some Of the other characterstics of TLESR. METHODS: The following parameters were measured: LES and crural diaphragm pressures using a reverse perfused Sleeve, crural diaphragm EMG activity, esophageal pH, 5 cms above the LES. Water was injected into the pharynx in the increasing volumes of .05, 0.1, 0.2, 0.3mi. Slow continous water injections in the pharynx (3ml\mint> induced LES relaxation was als0 studied. RESULTS: The LES relaxed in response to as little as .05 ml of rapid pharyngeal Water injection and maximal LES relaxation was seen at 0.2 to 0.3ral. The threshold for slow injection was 0.7 ml, higher than rapid injection. The duration of LES relaxation for rapid injection ranged from 4-80seconds ( mean = 30 sees). In contrast to LES, rapid as well as slow injection caused an increase of Crural diaphragm (CD) contraction during periods of LES relaxation. Response of LES and CD to different pharyngeal bolus volumes ' 0.05 ml LES Pressure -17+8%
0.1 ml
0.2 ml
0.3 ml
-43_+9%:
-59_+5%
-71_+6%
,
CD Pressure +7+28% +14_+7% +17_+16% +14_+11% l'here were no episodes of acid reflux or commoncavity during any of pharyngeal stimulated LES relaxations. CONCLUSIONS:Our data suggest that the characterstics of LES relaxation induced by pharyngeal water stimulation resemble only partly with TLESR.
DUODENOGASTROESOPHAGEAL REFLUX- EVALUATION OF SIMULTANEOUS AMBULATORY ESOPHAGEAL PH AND BILIRUBIN MONITORING. M.G. Choi, S.H. Park, J.Y. Han, I.S. Chung, K.W. Chung, H.S. Sun, D.H. Park. Dept. of Internal Medicine, Catholic University Medical College, Seoul, Korea Background/Aims: Esophageal reflux damage may be produced by agents other than acid and the term "alkaline esophagitis' has been applied. Esophageal pH monitoring to assess duodenogastroesophageal reflux has been suggested but gastric neutralization has made these methods difficult to prove conclusively. To investigate the role of duodenogastroesophageal reflux in GERD, we performed simultaneous esophageal pH and bilirubin monitoring(Bilitec 2000, Synetics Medical, Sweden) in 14 symptomatic Korean patients with gastroesophageal reflux and 12 healthy controls. Abnormal reflux was defined when the percent total time of pH < 4 or bilirubin absorbance > 0.14 exceeded the 95th percentile of the range obtained in healthy volunteers. Results: (1) Abnormal gastroesophageal reflux was diagnosed in 11(78.6%) of 14 patients, who could be categorized into acid refluxers(36.4%), bile refluxers(9.1%) or combined acid and bile refluxers(54.5%). (2) All 6 patients with severe esophagifis (>grade 2) were combined refluxers and had markedly prolonged bile reflux compared to 8 patients with normal or miJd esophagitis(percent total time of bilirubin absorbance > 0.14 (mean+-SE): 30.3+-6.9% vs 10.9+-4.5%, P<0.05). (3) Mean pH of esophageal refluxate during bile reflux episode lasting longer than 5 minutes was 6.0(9.3% for pH <4, 8.8% for pH 4-5, 26.6% for pH 6-7, 47% for pH 6-7 and 8.3% for pH >7). (4) 8 patients with a symptom index greater than 25% experienced 24 reflux symptoms of which 12(50.0%) were associated with acid reflux, 5(20.8%) were associated with bile reflux and 7(29.2%) were not associated with bile or acid reflux. Conclusions: (1) Alkaline esophageal reflux is a misnomer. Esophageal pH monitoring does not adequately identify symptomatic non-acidic duodenogastroesophageal reflux. (2) Patients with combined acid and bite reflux are more likely to develop severe esophagitis.
A583
• MECHANISMS OF PROGESTERONE INDUCED GALLBLADDER HYPOMOTILITY IN GUINEA PIGS. V. Chitnavis, P. Yu, O. Chen. P. Biancani and J. Behar. Department of Medicine, Rhode Island Hospital and Brown University School of Medicine. Providence, R.I. Adult male guinea pigs were used to study the mechanisms by which progesterone impairs gallbladder muscle contractility. Animals received either daily subcutaneous injections of progesterone (2 mg/kg for 7 days) or placebo. Gallbladder muscle cells were isolated by enzymatic digestion with collagenase and permeabilized with saponin as needed. Contraction was express as % shortening with respect to untreated cells. Contraction in response to CCK (10-13 M to 10-7 M) was significantly reduced in animals treated with progesterone (maximal shortening of 115+1% at 10-8 M CCK) when compared to control animals (20-+1%, P<0.05). However, the dose-dependent contractions caused by KC1, which is receptor-G protein independent, were not significantly different (Anova) in these two groups of animals. Contraction in response to direct G-protein activation with GTlh,S and aluminum fluoride (A1F) was. similarly reduced in muscle cells from the progesterone treated animals. GTPTS at 10-4 M caused a maximal shortening of 11+1% as opposed to 22+1% in controls. A1F caused a maximal shortening of 13+1% and 20i-1% in progesterone-treated and control animals, respectively (P<0.01). In contrast, IP3 (10-11 M to 10-5M) contracted the muscle cells in a dose dependent manner in the progesterone treated animals with a maximal contraction of 21+1% which is not different from controls. To further assess the function of G-proteins, we examined their GTP binding properties using 35S-labeled GTPtS (0.5 nM) in muscle membranes in the presence of 2 I/M GDP, 5 mM Mg2+, 100 mM Na+, 50 mM Tris, pH 7.5, 1 mM EDTA and 1 mM dithiothreitol. 35SGTP%,S binding reached a plateau at 40 min, which was chosen for subsequent experiments. The binding was suppressed by both GDP and unlabeled GTPyS in a concentration-dependent manner, suggesting that binding is specific. The binding was dose-dependently stimulated by CCK (10-11-10-6 M) in normal prairie dogs, with a maximal increase of 73_+16% from basal level at 10-8 M of CCK. CCK-induced stimulation was significantly suppressed in progesterone treated animals with a maximal increase of 21+7% from basal level at 10-8 M of CCK. In conclusion, progesterone may impair gallbladder muscle contractility by affecting G proteins.
ELECTROGASTROGRAPHIC FINDINGS IN CYCLIC VOMITING SYNDROME (CVS). S.K.F. Chonq, T. Nowak, M. Goddard, J. Flueckiger, J.M. Croffie, J.F. Fitzgerald. Depts. of Pediatric Gastroenterology and Nutrition and Adult Gastroenterology, Indiana University School of Medicine, Indianapolis, IN Cyclic vomiting syndrome is characterized by repeated, prolonged episodes of severe vomiting in childhood, usually starting suddenly and lasting from hours to days (commonly 1-4 days). It is of unknown etiology and the intensity of the vomiting spell can lead to dehydration. No treatment has been effective to prevent the attacks, but anti-migraine medication has been u s e d . We have studied 8 children (5 female, 3 male), ages 4-13 years, who presented from J u n e 1 9 9 3 to Dec 1994 with intractable symptoms occurring once every 2 to 6 weeks and compared the electrogastrography (EGG) to 3 normal control children (siblings) and 3 disease controls (H. pylori gastritis, recurrent abdominal pain). The healthy normal children were aged 5-12 years. Five of the eight children were on treatment with propranolol, cisapride or metoclopramide. Two hours after a light breakfast, each subject lay supine and four bipolar electrodes were placed at equidistant loci on the upper abdomen. The electrodes were situated parallel to the longitudinal axis of the stomach. Recordings were obtained for 60 minutes before and after ingestion of a light meal. Pre- and postprandial signals were digitized at 1 Hz and subjected to autoregressive spectral analysis. Six children presented with episodes of taehygastria during the acute illness. All subjects showed a predominant 3 cpm rhythm. However, the patients with CVS showed evidence of tachygastria during the acute symptoms. Three of the 6 showed episodes of tachygastria (4-6 cpm) after eating. The tracing of 4-6 cpm Occurred at an average duration of 1-3 minutes during the recordings. EGG abnormalities are seen in children with CVS. The changes are transient and are best diagnosed during an acute episode. Tachygastria is the most frequent abnormality seen during a 2 hour monitoring. Further studies should be performed over a longer time (24-hour recordings) period at home where attacks frequently occur in order to predict the timing of episodes and to plan management.