ISSN:
1573-2568
Keywords:
AMMONIA
;
MONOCHLORAMINE
;
GASTRIC MUCOSAL LESIONS
;
POLAPREZINC
;
ZINC L-CARNOSINE
;
SUCRALFATE
;
H. PYLORI
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Effects of a novel zinc compound polaprezinc[N-(3-aminopropionyl)-L-histidinatozinc] and sucralfateon the mucosal ulcerogenic responses induced bymonochloramine (NH2Cl) were examined in ratstomachs. Oral administration of NH2Cl (≥60mM) produced severe lesions in unanesthetized ratstomachs, with concomitant increase of lipidperoxidation. These lesions were aggravated by sensorydeafferentation but not affected by pretreatment with indomethacinor L-NAME. The mucosal ulcerogenic response toNH2Cl was significantly inhibited by oralpretreatment with either dmPGE2 (10μg/kg), capsaicin (30 mg/kg), or NOR-3 (3 mg/kg), the NO donor. Gastriclesions induced by NH2Cl were also inhibitedby prior oral administration of polaprezinc (3-30 mg/kg)as well as sucralfate (30 and 100 mg/kg). The protectiveeffect of polaprezinc was not affected by anypretreatments such as indomethacin, L-NAME, or sensorydeafferentation, while that of sucralfate wassignificantly mitigated in the presence of eitherindomethacin or L-NAME. On the other hand, mucosal exposureto NH2OH (60 mM) caused a marked PD reductionin ex vivo stomachs made ischemic by bleeding from thecarotid artery, followed by severe gastric lesions.These ulcerogenic and PD responses caused by NH OHplus ischemia were also attenuated by prior applicationof polaprezinc, while dmPGE2 and sucralfateprevented such lesions without affecting the reduced PDresponse. These results suggest that: (1)NH2Cl generated either exogenously orendogenously damages the gastric mucosa, (2) bothpolaprezinc and sucralfate protect the stomach againstinjury caused by NH2Cl, and (3) the mechanisms underlying the protectiveaction of sucralfate may be partly mediated by bothendogenous PGs and NO but may be different from those ofpolaprezinc.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1018847324172
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