title: Histochemical studies on gamma-glutamyltranspeptidase activity of pancreatic acinar cell lesions induced by 4-hydroxyaminoquinoline 1-oxide and/or azaserine in rats.
abstract: The utility of gamma-glutamyltranspeptidase (gamma-GTP) as an enzyme marker during pancreatic acinar cell carcinogenesis in rats was assessed by measuring its enzyme-histochemical performance in pancreatic acinar cell lesions induced by 4-hydroxyaminoquinoline 1-oxide (4-HAQO) and/or azaserine in partially-pancreatectomized Fischer 344 and Wistar rats. Rats were given a single intravenous injection of 4-HAQO (10 or 7 mg/kg body weight) 3 days after partial pancreatectomy followed by intraperitoneal injections of azaserine (30 mg/kg) once a week for 10 weeks, or the same treatment without azaserine. The animals were sacrificed at 3, 6, 10, 12 and 18 months. 4-HAQO predominantly induced basophilic foci in Fischer rats, while in Wistar rats acidophilic foci and acidophilic hyperplastic nodules were predominant. A preferential enhancement of the induction of acidophilic foci and hyperplastic nodules was exhibited in Fischer rats following co-administration with azaserine. Normal acinar cells were positive for gamma-GTP. 90 to 100% of basophilic foci were either negative or slightly positive for gamma-GTP, whilst 68 to 98% of acidophilic foci were positive. The gamma-GTP activities of acidophilic hyperplastic nodules were more variable between nodules than within nodules, and either co-administration of azaserine or extension of experimental duration time appeared to increase the gamma-GTP positive nodules. Between the gamma-GTP positive and decreased nodules, no histological but some morphometrical differences were observed. As far as the nodules induced by 4-HAQO in Fischer rats were concerned, all of the gamma-GTP decreased nodules had thin fibrous capsules and exhibited ultrastructurally more atypia than the positive ones. Present study thus revealed that gamma-GTP is neither a useful nor invariable enzyme marker during pancreatic acinar cell carcinogenesis in rats.
mesh_terms: D015108:4-Hydroxyaminoquinoline-1-oxide; D000818:Animals; D001377:Azaserine; D001835:Body Weight; D002471:Cell Transformation, Neoplastic / Q000139:chemically induced / Q000378:metabolism* / Q000473:pathology; D006651:Histocytochemistry; D006965:Hyperplasia; D008297:Male; D008854:Microscopy, Electron; D010179:Pancreas / Q000201:enzymology* / Q000473:pathology / Q000648:ultrastructure; D010190:Pancreatic Neoplasms / Q000139:chemically induced / Q000201:enzymology* / Q000473:pathology; D011230:Precancerous Conditions / Q000139:chemically induced / Q000201:enzymology* / Q000473:pathology; D051381:Rats; D011916:Rats, Inbred F344; D011919:Rats, Inbred Strains; D005723:gamma-Glutamyltransferase / Q000378:metabolism*
chemical_list: D015108:4-Hydroxyaminoquinoline-1-oxide; D001377:Azaserine; D005723:gamma-Glutamyltransferase