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Pepper and peristalsis
590
GASTROENTEROLOGY
SELECTED SUMMARIES
weight loss to allow examination of the effect of the cancer itself. The data justify the method. The cancer-cachexia group stands out as one behaving as a “stressed” group with protein turnover values clearly greater than nonstarved malnourished patients or starved controls. With such a demonstration, the most logical question is, why these differences? What is the biochemical basis of the high nitrogen turnover? Is it hormonally mediated; is it particularly marked in certain types of cancer? If a cause is found, perhaps a remedy will be devised. If so, will it improve the function and feeling of well-being in the incurable cancer patient? Answers to these questions, if they can be found, should prove exciting. W. G. M. HARDISON, M.D.
PEPPER AND PERISTALSIS Donnerer 1, Barth0 L, Holzer P, Lembeck F (Department of Experimental and Clinical Pharmacology, University of Graz, Universitatsplatz 4, Graz, Austria A-8010) Intestinal peristalsis associated with release of immunoreactive substance P. Neuroscience 1984;11:913-8 (April). The authors have previously suggested that substance P mediates the atropine-resistant excitatory pathway of the peristaltic reflex. Here they examine whether intestinal peristalsis is associated with a release of substance P into the vascular bed of the gut. A measurable release can be expected because most circulatory substance P is known to originate in the gut. The small intestine of guinea pigs was placed in an organ bath. The mesenteric artery and the portal vein were cannulated to perfuse the intestine with physiologic solution and to collect its venous effluent. The effluent was collected in fractionated samples and its substance P content was measured by radioimmunoassay. Immunoreactive substance P was barely detectable in venous samples under basal conditions, but triggering the peristaltic reflex released large quantities of it. Arterial administration of hexamethonium abolished the peristaltic reflex in response to intestinal distention; it reduced, but failed to abolish the release of substance P. This may be due to a direct response to distention or due to some other, complicated, mechanism. Pretreatment of guinea pigs with capsaicin did not diminish release of substance P during the peristaltic response. Because chronic capsaicin administration damages selectively those substance P neurons that are sensory in nature and of extrinsic origin, the substance P released as part of the peristaltic reflex must be of intrinsic origin. Acute administration of capsaicin is known to release substance P and thereby to facilitate the peristaltic reflex: this was confirmed here as intraarterial infusion of capsaicin-induced peristaltic contractions and increased the level of substance P in the effluent. Both responses were absent in animals that had been pretreated with substance P. Comment. The alkaloid capsaicin is the pungent principle derived from plants of the genus Capsicum or hot pepper. Hot peppers are credited with keeping one’s bowels open; because of this critical action, the defense establishment of this country keeps tabs on the pepper consumption abroad; according to its
Vol. 88. No. 2
estimates, the average Thai eats 60-70 g of hot pepper a day (U.S. Interdepartmental Committee on Nutrition for National Defense, The Kingdom of Thailand: Nutrition Survey 1962:57-g).Because nothing is known about the rate at which capsaicin is absorbed, it is uncertain whether the laxative action of capsaicin relates to the initiation of the peristaltic reflex by release of substance P as described here. Other, nonperistaltic, mechanisms have been proposed for the laxative action of hot pepper. Noting that uncoupling of electrical slow waves is an event common to many diarrhea1 states, including those induced by ricinoleate and quinidine (Gastroenterology 1972;62:1167-73, Gastroenterology 1972;63:1011-5, Gastroenterology 1973;65:773-7), Anuras and Christensen examined the effect of capsaicin on the electrical activity of the isolated cat colon (Gut 1977;18:666-9). They found that capsaicin slowed the electrical activity of the proximal but not the distal colon; assuming that the contractile activity of the colon is paced by the electrical activity as it is in the small bowel, this electrical uncoupling would be likely to alter colonic movements and hence water absorption. K. SCHULZE-DELRIEU. M.D.
IS pH OF ASCITIC FLUID USEFUL DETECT INFECTION?
TO
Attali P, PeJJetier G, Douard H, et al. (Service des Maladies du Foie et de 1’Appareil Digestif, H6pital de Bi&tre, Le Kremlin-Bichtre, France). pH et infection de l’ascite dans la cirrhose alcoolique (pH and infection of ascitic fluid in alcoholic cirrhosis). Gastroenterol Clin Biol 1984;8:518-22
(June). A decrease in the pH of ascitic fluid has been proposed as a diagnostic test of infection of ascites (or spontaneous bacterial peritonitis). To further examine the validity of this test, Attali and his associates have measured ascitic fluid pH in 108 samples from 94 patients. As ascitic fluid pH may be influenced by systemic pH, they have also measured the arterial-ascitic pH difference. The 94 cirrhotic patients included 71 men and 23 women, aged 32-83 yr (mean 56 yr). Paracentesis was performed on the day of admission to the hospital. A second paracentesis was eventually performed during a subsequent hospitalization at least 3 mo apart. The following tests were performed on the ascitic fluid: (a) a red and white blood cell count; (b) aerobic and anaerobic cultures, as well as a direct bacteriologic examination; and (c) pH measurement on 5 ml of ascitic fluid collected in a nonheparinized syringe immediately sealed and taken to the laboratory. A simultaneous arterial blood sample was drawn for blood pH measurement and the blood-ascites pH difference was calculated in all patients. The patients were divided into three groups: group 1 comprised 83 patients (97 samples) with a sterile fluid and no clinical sign of infection; group 2 comprised 6 patients (6 samples) with an infected fluid (3 with E. coli, 1 with Streptococcus type D, 1 with KJebsieJJa ozenae, 1 with an association of E. coli and KJebsieJJa pneumoniae); and group 3 comprised 5 patients (5 samples) with a possible infection (in particular with >75 polymorphonuclear leukocytes per microliter) but with a sterile culture. It was found that ascitic fluid pH was significantly lower (p < 0.001, non-
GASTROENTEROLOGY
SELECTED SUMMARIES
weight loss to allow examination of the effect of the cancer itself. The data justify the method. The cancer-cachexia group stands out as one behaving as a “stressed” group with protein turnover values clearly greater than nonstarved malnourished patients or starved controls. With such a demonstration, the most logical question is, why these differences? What is the biochemical basis of the high nitrogen turnover? Is it hormonally mediated; is it particularly marked in certain types of cancer? If a cause is found, perhaps a remedy will be devised. If so, will it improve the function and feeling of well-being in the incurable cancer patient? Answers to these questions, if they can be found, should prove exciting. W. G. M. HARDISON, M.D.
PEPPER AND PERISTALSIS Donnerer 1, Barth0 L, Holzer P, Lembeck F (Department of Experimental and Clinical Pharmacology, University of Graz, Universitatsplatz 4, Graz, Austria A-8010) Intestinal peristalsis associated with release of immunoreactive substance P. Neuroscience 1984;11:913-8 (April). The authors have previously suggested that substance P mediates the atropine-resistant excitatory pathway of the peristaltic reflex. Here they examine whether intestinal peristalsis is associated with a release of substance P into the vascular bed of the gut. A measurable release can be expected because most circulatory substance P is known to originate in the gut. The small intestine of guinea pigs was placed in an organ bath. The mesenteric artery and the portal vein were cannulated to perfuse the intestine with physiologic solution and to collect its venous effluent. The effluent was collected in fractionated samples and its substance P content was measured by radioimmunoassay. Immunoreactive substance P was barely detectable in venous samples under basal conditions, but triggering the peristaltic reflex released large quantities of it. Arterial administration of hexamethonium abolished the peristaltic reflex in response to intestinal distention; it reduced, but failed to abolish the release of substance P. This may be due to a direct response to distention or due to some other, complicated, mechanism. Pretreatment of guinea pigs with capsaicin did not diminish release of substance P during the peristaltic response. Because chronic capsaicin administration damages selectively those substance P neurons that are sensory in nature and of extrinsic origin, the substance P released as part of the peristaltic reflex must be of intrinsic origin. Acute administration of capsaicin is known to release substance P and thereby to facilitate the peristaltic reflex: this was confirmed here as intraarterial infusion of capsaicin-induced peristaltic contractions and increased the level of substance P in the effluent. Both responses were absent in animals that had been pretreated with substance P. Comment. The alkaloid capsaicin is the pungent principle derived from plants of the genus Capsicum or hot pepper. Hot peppers are credited with keeping one’s bowels open; because of this critical action, the defense establishment of this country keeps tabs on the pepper consumption abroad; according to its
Vol. 88. No. 2
estimates, the average Thai eats 60-70 g of hot pepper a day (U.S. Interdepartmental Committee on Nutrition for National Defense, The Kingdom of Thailand: Nutrition Survey 1962:57-g).Because nothing is known about the rate at which capsaicin is absorbed, it is uncertain whether the laxative action of capsaicin relates to the initiation of the peristaltic reflex by release of substance P as described here. Other, nonperistaltic, mechanisms have been proposed for the laxative action of hot pepper. Noting that uncoupling of electrical slow waves is an event common to many diarrhea1 states, including those induced by ricinoleate and quinidine (Gastroenterology 1972;62:1167-73, Gastroenterology 1972;63:1011-5, Gastroenterology 1973;65:773-7), Anuras and Christensen examined the effect of capsaicin on the electrical activity of the isolated cat colon (Gut 1977;18:666-9). They found that capsaicin slowed the electrical activity of the proximal but not the distal colon; assuming that the contractile activity of the colon is paced by the electrical activity as it is in the small bowel, this electrical uncoupling would be likely to alter colonic movements and hence water absorption. K. SCHULZE-DELRIEU. M.D.
IS pH OF ASCITIC FLUID USEFUL DETECT INFECTION?
TO
Attali P, PeJJetier G, Douard H, et al. (Service des Maladies du Foie et de 1’Appareil Digestif, H6pital de Bi&tre, Le Kremlin-Bichtre, France). pH et infection de l’ascite dans la cirrhose alcoolique (pH and infection of ascitic fluid in alcoholic cirrhosis). Gastroenterol Clin Biol 1984;8:518-22
(June). A decrease in the pH of ascitic fluid has been proposed as a diagnostic test of infection of ascites (or spontaneous bacterial peritonitis). To further examine the validity of this test, Attali and his associates have measured ascitic fluid pH in 108 samples from 94 patients. As ascitic fluid pH may be influenced by systemic pH, they have also measured the arterial-ascitic pH difference. The 94 cirrhotic patients included 71 men and 23 women, aged 32-83 yr (mean 56 yr). Paracentesis was performed on the day of admission to the hospital. A second paracentesis was eventually performed during a subsequent hospitalization at least 3 mo apart. The following tests were performed on the ascitic fluid: (a) a red and white blood cell count; (b) aerobic and anaerobic cultures, as well as a direct bacteriologic examination; and (c) pH measurement on 5 ml of ascitic fluid collected in a nonheparinized syringe immediately sealed and taken to the laboratory. A simultaneous arterial blood sample was drawn for blood pH measurement and the blood-ascites pH difference was calculated in all patients. The patients were divided into three groups: group 1 comprised 83 patients (97 samples) with a sterile fluid and no clinical sign of infection; group 2 comprised 6 patients (6 samples) with an infected fluid (3 with E. coli, 1 with Streptococcus type D, 1 with KJebsieJJa ozenae, 1 with an association of E. coli and KJebsieJJa pneumoniae); and group 3 comprised 5 patients (5 samples) with a possible infection (in particular with >75 polymorphonuclear leukocytes per microliter) but with a sterile culture. It was found that ascitic fluid pH was significantly lower (p < 0.001, non-