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Effect of ionizing radiation on gastric secretion in vivo in response to histamine and pentagastrin
GASTROENTEROLOGY
1987;92:2057-65
ABSTRACTS OF PAPERS SUBMITTED TO ‘tHE AMERICAN GASTROENTEROLOGICAL ASSOCIATION AND THE AMERICAN ASSOCIATION FOR THE STUDY OF LIVER DISEASE Unfortunately, these abstracts were not received in time to be included in the May 1987 issue. However, they have been reviewed by the AGA Program Committee and are reproduced below.
EFFECT OF IONIZING RADIATION ON GASTRIC SECRETION IN VIVO IN RESPONSE TO HISTAMINE AND PENTAGASTRIN. Shmuel Batxri and Georae Catravag Uniformed Services University of the Healtlt Sciences and Armed Forces Radiobiolegy Research Insitiute, Bethesda, Md. 20814-4799 Ionizing gamma radiation is widely used in radiation therapy and at high doses can produce a variety of gastrointestinal changes. We explored the darnaging effect of ionizing radiation on guinea pi8 gastric mucosa m and its potential mechanism. Guinea pigs were surgically implanted with permanent gastric cannulae which enabled access into their stomach. Combined with a dye dilution technique, the gastric cannula allowed US to measure simultaneously acid and fluid secretion. Under normal conditions prior to irradiation continuous infusion of histamine or pentagastrin (each 30 ug/kg/h) increased acid and fluid output 2-5 fold within 30-60 min after the start of infusion. Exposure of t animais to sublethal doses of whole body ionixing radiation (%l CO source, 1 Gy/min) inhibited both basal and hastamine and pentagastrin stimulated acid output within 2h of irradiation. A significant inhibition of acid output was observed at 0.5 Gy (50 rad), halfmaxima1 at 1-2 Gy (100-200 rad) and maxima1 at 6-8 Gy, at which fluid and acid output were practically abolished. We next explored the possibility that ionizing radiation directly damaged the histamine receptors and thereby inhibiting histamine stimulated acid output. Gastric glands were prepared from the rabbit and we amined their acid secretory response by their ability to accumulate 5’4C-aminopyrine (AP) in response to histamine. Exposure of gastric glands to ionizing radiation at doses from 0.5 to 128 Gy (50-12800 rad), had no significant effect on AP accumulation. That is, histamine induced AP accumulation was the same before and after radiation exposure. We tentatively conclude that the damaging effect of ioniaing radiation in whicli is reflected by inhibition of acid and fluid output is probably not due to a direct effect of radiation on histamine receptors.
TO ESOPHAGITIS ESOPHAGEAL pH MONITQRING CORRELATED (BARRETT'S) IN CHILDREN. UE Berquist Lee Youkeles, ME Ament. Departments of Pediatrics and Biostatics, University of California, Lös Angeles, CA. Quantitive storing of esophageal pH monitoring for gastroesophageal reflux disease was compared to controls and correlated to esophageal biopsies in children. Using a manometrically positioned pH probe above the lower esophageal sphincter (LES), 60 children evaluated by pH monitoring also had coded esophageal biopsies reviewed independently by 2 pathologists. The esophageal pH scores for frequency, longest episode, and duration (% reflux time) were evaluated for sleep, 2 hours post prandial (pp) and total intervals in normal or biopsy normal children (Normal), esophagitis biopsy pasitive children (esophagitis) and Barrett's esophagus positive children (Barrett's). Sex LES Pressure %Reflux Age k Years(SD) mnHg(SD) pp SD Normal 40 2:i?9 2.6l3.81 31.II15.51 6.6t8.41 Esophagitis 16 7:9 3.4(4.4j 24;2(I2:9j I9.4(2i.á)t Barrett's 4 0:4 10.7(2.6) 9.2(9.0)* 54.2(17.5)tt * p < .Ol, ANOV t p < .05, Esophagitis VS normal tt p < .OOl, Normal vs. esophagitis vs. Barrett's By stepwise discrimination, there was no other superior storing value or combination of values. CONCLUSION: (1) % reflux pp rather than prolpnged pH monitoring (24 hours) is sufficient to predict esophagitis and Barrett's esophagitis risk. (2) Children with Barrett's were al1 males and had abnormally low LES pressure. For screening of esophagitis risk, shorter 2 hour post prandial studies may suffice.
1987;92:2057-65
ABSTRACTS OF PAPERS SUBMITTED TO ‘tHE AMERICAN GASTROENTEROLOGICAL ASSOCIATION AND THE AMERICAN ASSOCIATION FOR THE STUDY OF LIVER DISEASE Unfortunately, these abstracts were not received in time to be included in the May 1987 issue. However, they have been reviewed by the AGA Program Committee and are reproduced below.
EFFECT OF IONIZING RADIATION ON GASTRIC SECRETION IN VIVO IN RESPONSE TO HISTAMINE AND PENTAGASTRIN. Shmuel Batxri and Georae Catravag Uniformed Services University of the Healtlt Sciences and Armed Forces Radiobiolegy Research Insitiute, Bethesda, Md. 20814-4799 Ionizing gamma radiation is widely used in radiation therapy and at high doses can produce a variety of gastrointestinal changes. We explored the darnaging effect of ionizing radiation on guinea pi8 gastric mucosa m and its potential mechanism. Guinea pigs were surgically implanted with permanent gastric cannulae which enabled access into their stomach. Combined with a dye dilution technique, the gastric cannula allowed US to measure simultaneously acid and fluid secretion. Under normal conditions prior to irradiation continuous infusion of histamine or pentagastrin (each 30 ug/kg/h) increased acid and fluid output 2-5 fold within 30-60 min after the start of infusion. Exposure of t animais to sublethal doses of whole body ionixing radiation (%l CO source, 1 Gy/min) inhibited both basal and hastamine and pentagastrin stimulated acid output within 2h of irradiation. A significant inhibition of acid output was observed at 0.5 Gy (50 rad), halfmaxima1 at 1-2 Gy (100-200 rad) and maxima1 at 6-8 Gy, at which fluid and acid output were practically abolished. We next explored the possibility that ionizing radiation directly damaged the histamine receptors and thereby inhibiting histamine stimulated acid output. Gastric glands were prepared from the rabbit and we amined their acid secretory response by their ability to accumulate 5’4C-aminopyrine (AP) in response to histamine. Exposure of gastric glands to ionizing radiation at doses from 0.5 to 128 Gy (50-12800 rad), had no significant effect on AP accumulation. That is, histamine induced AP accumulation was the same before and after radiation exposure. We tentatively conclude that the damaging effect of ioniaing radiation in whicli is reflected by inhibition of acid and fluid output is probably not due to a direct effect of radiation on histamine receptors.
TO ESOPHAGITIS ESOPHAGEAL pH MONITQRING CORRELATED (BARRETT'S) IN CHILDREN. UE Berquist Lee Youkeles, ME Ament. Departments of Pediatrics and Biostatics, University of California, Lös Angeles, CA. Quantitive storing of esophageal pH monitoring for gastroesophageal reflux disease was compared to controls and correlated to esophageal biopsies in children. Using a manometrically positioned pH probe above the lower esophageal sphincter (LES), 60 children evaluated by pH monitoring also had coded esophageal biopsies reviewed independently by 2 pathologists. The esophageal pH scores for frequency, longest episode, and duration (% reflux time) were evaluated for sleep, 2 hours post prandial (pp) and total intervals in normal or biopsy normal children (Normal), esophagitis biopsy pasitive children (esophagitis) and Barrett's esophagus positive children (Barrett's). Sex LES Pressure %Reflux Age k Years(SD) mnHg(SD) pp SD Normal 40 2:i?9 2.6l3.81 31.II15.51 6.6t8.41 Esophagitis 16 7:9 3.4(4.4j 24;2(I2:9j I9.4(2i.á)t Barrett's 4 0:4 10.7(2.6) 9.2(9.0)* 54.2(17.5)tt * p < .Ol, ANOV t p < .05, Esophagitis VS normal tt p < .OOl, Normal vs. esophagitis vs. Barrett's By stepwise discrimination, there was no other superior storing value or combination of values. CONCLUSION: (1) % reflux pp rather than prolpnged pH monitoring (24 hours) is sufficient to predict esophagitis and Barrett's esophagitis risk. (2) Children with Barrett's were al1 males and had abnormally low LES pressure. For screening of esophagitis risk, shorter 2 hour post prandial studies may suffice.