Nitric oxide production by kupffer cells in obstructive jaundiced rats: The effect of internal andexternal drainage

Nitric oxide production by kupffer cells in obstructive jaundiced rats: The effect of internal andexternal drainage

ABSTRACTS IN DDW PROGRAM ACCEPTED AS ORAL OR POSTER PRESENTATIONS TO THE SOCIETY FOR SURGERY OF THE ALIMENTARY TRACT 2217 NITRIC OXIDE PRODUCTION BY K...

97KB Sizes 0 Downloads 38 Views

ABSTRACTS IN DDW PROGRAM ACCEPTED AS ORAL OR POSTER PRESENTATIONS TO THE SOCIETY FOR SURGERY OF THE ALIMENTARY TRACT 2217 NITRIC OXIDE PRODUCTION BY KUPFFER CELLS IN OB· STRUCTIVE JAUNDICED RATS: THE EFFECT OF INTERNAL AND EXTERNAL DRAINAGE. Wen Li, James Yw Lau, Danny Wh Lee, Enders Kw Ng, Angus Cw Chan, Joseph Jy Sung, Sydney Sc Chung, The Chinese Univ of Hong Kong, Hong Kong, P. R. China. Background: Nitric oxide, a small molecule that serves as a biological messenger, has been implicated in many disease processes. Its role in obstructive jaundice has not been extensively studied. Aims: To study nitrite production (as a measure of nitric oxide production) by Kupffer cells in experimental obstructive jaundice and the effect of internal and external drainage. Materials and Methods: Eighty male Sprague-Dawley rats weighing 300-350 g were randomized into four groups: sham operation (SH, n=25), obstructive jaundice by bile duct ligation and division (OJ, n=25), internal drainage by choledochoduodenostomy (ID, n= 15) and external drainage by exteriorizing a biliary drainage tube at the nape (ED, n = 15). Kupffer cells were isolated by in situ perfusion method with collagenase D as the digestive enzyme on day 7 in the SH and OJ groups and on day 14 (i.e. day 7 after drainage surgery) in the ID and ED groups. Kupffer cells were cultured with or without lipopolysaccharide (LPS, 100 ng/ml) as an activator respectively in 96-well plates. The nitrite productionin in cell culture supernatants was measured 48 hrs later using Greiss reagents. Results: There was no significant difference of nitrite production between the four groups without LPS stimulation (SA, 245.4::':42.5; OJ, 234.4::':46.2; ID, 168.3::':34.3; ED, 313.1::':98.6 nmol/mg protein)(P=0.489). When LPS was used as an activator, the nitrite production of Kupffer cells was significantly increased in OJ rats (698.5::': 10 1.3 nmol/mg) as compared with SH rats (275.2::':49.8 nmol/mg) (P=O.OOI). After drainage procedures, the impaired Kupffer cell function was recovered by ID (270.5 ::':46.4 nmol/mg) (P=0.007), but not by ED (502.7::': 114.0 nmol/mg) (P=0.769). Conclusion: Kupffer cells produce more nitric oxide in rats with obstructive jaundice. Internal biliary drainage depresses the generation of nitric oxide, but external drainage does not.

2218 BACTERIA ASSOCIATED WITHPIGMENT MAYPARTICIPATE IN CHOLESTEROL GALLSTONE FORMATION. Lygia Stewart, Adair L. Oesterle, Ihsan Erden, Lawrence W. Way, UCSF, San Francisco, CA; Sf Vamc, San Francisco, CA; SF State Univ, San Francisco, CA. Bacteria are thought to have a role in the pathogenesis of pigment but not cholesterol gallstones. This data suggests that bacteria are also involved in cholesterol gallstone formation. We prospectively examined gallstones from 370 patients, of which 204 were predominantly cholesterol stones with a variable amount of visible pigment. Based on visual appearance, these stones were classified into 3 groups: 94 (46%), cholesterol stones with no visible pigment (Ch); 73 (36%), mixed cholesterol stones with a pigment center (MCh); and 37(18%), cholesterol stones with a pigment coat (Ch-PE). The presence of bacteria in the stones (obtained sterilely) was detected using scanning electron microscopy (SEM) (149 stones) and stone culture (121 stones). The stones chemical composition was determined using IR spectroscopy. Bacteria obtained from the stones were tested for slime and f3-glucuronidase production. Results: The relationship between bacteria and cholesterol content in the different kinds of stones is shown in the table. The relationship between cholesterol content and bacterial presence and was as follows: 100% cholesterol, none with bacteria; >90% cholesterol, 44% had bacteria; and <90% cholesterol, 74% had bacteria. 73% of infected stones had one or more bacterial species that produced slime, and 36% had bacterial species that produced f3-glucuronidase. Conclusions: About 30% of these gallstones contained bacteria, and visible evidence of a pigment focus was a good predictor of bacterial presence. Nethertheless, even stones containing more than 90% cholesterol sometimes contained bacteria. Chemical composition alone did not distinguish the usually sterile Ch from MCh stones (which could contain bacteria). Bacteria found in cholesterol stones generally produced bacterial slime. These data suggest that bacteria may participate in cholesterol gallstone formation, either acting as a nidus for cholesterol precipitation or by facilitating stone growth by fostering the formation of a pigment coat.

Bacteria Present Cholesterol Content

Ch

Visual Appearance MCh

Ch-PE

3% 95%

34% 94%

64%

81%