Early exposure to restraint stress enhances chemical carcinogenesis in rat liver.
This study examines the effect of a stress-associated condition on chemical hepatocarcinogenesis in the rat. Rats were given diethylnitrosamine (200 mg/kg. b.w., i.p.), followed, 1 week later, by three cycles of immobilization at room temperature. Two weeks after the last cycle they were treated according to the resistant hepatocyte protocol. At 4 weeks after selection, mean size of glutathione-S-transferase 7-7 positive foci/nodules was increased in the immobilized group (0.82+/-0.22 vs. 0.25+/-0.04 mm(2) in controls). Furthermore, at the end of 1 year 10/13 animals (77%) developed hepatocellular carcinoma in the former group, while only 6/14 (43%) incidence of cancer was found in controls. These results indicate that exposure to restraint stress early during carcinogenesis enhances the development of chemically-induced hepatocellular carcinoma in the rat.
Laconi
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E
Dipartimento di Scienze Biomediche e Biotecnologie, Università di Cagliari, Via Jenner, 09125, Cagliari, Italy. elaconi@unica.it
Tomasi
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C
Curreli
F
F
Diana
S
S
Laconi
S
S
Serra
G
G
Collu
M
M
Pani
P
P
D000818:Animals; D001835:Body Weight; D002273:Carcinogens; D006528:Carcinoma, Hepatocellular / Q000139:chemically induced / Q000517:prevention & control; D004052:Diethylnitrosamine; D005982:Glutathione Transferase / Q000378:metabolism; D007103:Immobilization; D008113:Liver Neoplasms / Q000139:chemically induced*; D008297:Male; D009929:Organ Size; D051381:Rats; D011916:Rats, Inbred F344; D013312:Stress, Physiological; D013696:Temperature; D013997:Time Factors
D002273:Carcinogens; D004052:Diethylnitrosamine; D005982:Glutathione Transferase