Investigation of gastroprotective compounds at subcellular level in isolated gastric mucosal cells.
We tested the hypothesis that recognized gastroprotective agents exert direct protection against ethanol-induced injury in isolated rat gastric mucosal cells in vitro. If protection exists, we also wanted to identify subcellular targets in the reversible and/or irreversible stages of cell injury. Ethanol-induced cell injury was quantified by measuring plasma membrane leakage (trypan blue exclusion and lactate dehydrogenase release), mitochondrial integrity (succinic dehydrogenase), and nuclear damage (ethidium bromide-DNA fluorescence). Initial cell viability and responsiveness were estimated by the effects of carbachol, carbachol + atropine, or 16,16-dimethyl-PGE(2) on chief cell pepsinogen secretion. Enriched parietal cells were stimulated by histamine, carbachol, or histamine + IBMX. Preincubation of cells with PG, sucrose octasulfate, or the sulfhydryl compounds N-acetylcysteine, taurine, or cysteamine increased cell resistance </=21% against ethanol. Similar protection was found with low histamine concentrations, but a higher concentration aggravated ethanol toxicity. Other naturally occurring or synthetic gastroprotective agents offered partial protection or aggravated ethanol-induced cell injury. Only a few in vivo gastroprotective agents demonstrated in vitro direct cytoprotection, which involved mainly the reversible stage of cell injury (e.g., plasma membrane changes) and, less often, irreversible (e.g., mitochondrial and nuclear) damage. Our findings also indicate that a major part of the beneficial effect of gastroprotective agents is expressed at the tissue level.
Nagy
L
L
Chemical Pathology Research Division, Departments of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
Morales
R E
RE
Beinborn
M
M
Vattay
P
P
Szabo
S
S
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D015064:16,16-Dimethylprostaglandin E2 / Q000494:pharmacology; D000818:Animals; D001120:Arginine / Q000494:pharmacology; D001285:Atropine / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology; D002396:Catechols / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects; D002467:Cell Nucleus / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004353:Drug Evaluation, Preclinical / Q000379:methods; D000431:Ethanol / Q000633:toxicity; D005753:Gastric Mucosa / Q000187:drug effects*; D005765:Gastrointestinal Agents / Q000494:pharmacology*; D006632:Histamine / Q000494:pharmacology; D008928:Mitochondria / Q000187:drug effects; D009025:Morpholines / Q000494:pharmacology; D010422:Pentanones / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013438:Sulfhydryl Compounds / Q000494:pharmacology
D002396:Catechols; D005765:Gastrointestinal Agents; D009025:Morpholines; D010422:Pentanones; D013438:Sulfhydryl Compounds; D000431:Ethanol; D001285:Atropine; D006632:Histamine; D002217:Carbachol; D001120:Arginine; C057364:nitecapone; D015064:16,16-Dimethylprostaglandin E2; D015056:1-Methyl-3-isobutylxanthine; C013199:pinaverium