title: Decreased density of beta1-adrenergic receptors in preneoplastic and neoplastic liver lesions of F344 rats.
abstract: There is some evidence that rodent hepatocarcinogenesis is accompanied by changes in the adrenergic responsiveness of liver cells to catecholamines. In this study, immunohistochemical expression of beta1-adrenergic receptors (beta1-ARs) has been examined in spontaneous and chemically induced preneoplastic and neoplastic liver lesions of female and male Fischer 344 rats. An antibody specific for beta1-AR subtype was used. The study was carried out on archival formalin-fixed and paraffin-embedded livers from rats used in a previous study of hepatocarcinogenesis. One control group given distilled water by gavage, and two experimental groups, one initiated with a single dose of diethylnitrosamine (DEN) and one initiated with DEN and continuously treated with phenobarbital (PB) were examined. Rats were sacrificed after 2, 4, 8 and 21 months of experimentation. All types of liver putative preneoplastic lesions examined (basophilic, glycogen-retaining, or mixed cell foci) show a lower density of beta1-ARs than the surrounding normal liver parenchyma, either in control and in DEN-treated or DEN+PB-treated rats. No immunostaining is detectable in several altered cell foci. Hepatocellular adenomas and hepatocellular carcinomas also show a very low density of beta1-ARs, extensive areas completely devoid of beta1-ARs being mingled with areas showing a weak immunostaining.
authors.affiliation: Department of Biology, Faculty of Science, University of Milan, via Celoria 26, I-20133 Milan, Italy. rosanna.cardani@unimi.it
authors.forename: R
authors.initials: R
authors.lastname: Cardani
authors.forename: T
authors.initials: T
authors.lastname: Zavanella
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000378:metabolism / Q000473:pathology*; D004052:Diethylnitrosamine; D005260:Female; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000378:metabolism / Q000473:pathology*; D008114:Liver Neoplasms, Experimental / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology; D008297:Male; D010634:Phenobarbital; D011230:Precancerous Conditions / Q000378:metabolism / Q000473:pathology*; D051381:Rats; D011916:Rats, Inbred F344; D018342:Receptors, Adrenergic, beta-1 / Q000378:metabolism*; D013997:Time Factors
chemical_list: D018342:Receptors, Adrenergic, beta-1; D004052:Diethylnitrosamine; D010634:Phenobarbital