Initiation of cell proliferation in livers of the viviparous fish Poeciliopsis lucida with 7,12-dimethylbenz(a)anthracene

Journal Article · Sat Apr 01 00:00:00 EST 1989 · Environmental Research; (USA)

DOI:https://doi.org/10.1016/S0013-9351(89)80038-6· OSTI ID:7059157

Schultz, M E; Kaplan, L A.E.; Schultz, R J ^[1]

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1. The Univ. of Connecticut, Storrs (USA)

Stimulation of liver cell proliferation by sublethal exposures to 7,12-dimethylbenz(a)anthracene (DMBA) is examined in the small, viviparous fish Poeciliopsis lucida. Poeciliopsis is susceptible to induction of liver tumors by repeated short-term exposures, under 24 hr, to waterborne DMBA at 5 ppm. Exposures to 5 ppm for 24 hr was lethal to fish under 1 month old and resulted in 60% mortality of adult females 20-25 mm in length. Response to 16-, 20-, and 22-hr exposures of 5 ppm DMBA, as measured by mitotic index, was similar in females of two size classes, 20-25 mm and 26-30 mm. Differences were observed in the onset of mitosis in livers of fish exposed for 16 hr vs 20 or 22 hr. Hepatocyte proliferation did not begin until 10-11 days after the 16-hr exposure and lasted for only 3 days. When exposure was increased to 20 or 22 hr, mitotic activity was observed earlier, 2 days following treatment, and continued for 6-8 days. The peak period of cell proliferation also varied, occurring 12 days after a 16-hr exposure, 4 days after a 20-hr exposure, and at least 10 days after a 22-hr exposure. The mitotic index was the highest on the final day specimens of the 22-hr treatment were collected. These results suggest that the toxic properties of DMBA in stimulating cell proliferation may function as an important cofactor in hepatocarcinogenesis.

• OSTI ID: 7059157
• Journal Information: Environmental Research; (USA), Vol. 48:2; ISSN 0013-9351
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
DIMETHYLBENZANTHRACENE
TOXICITY
LIVER
CELL PROLIFERATION
CARCINOGENESIS
FISHES
MITOSIS
MITOTIC INDEX
MORTALITY
NEOPLASMS
ANIMALS
AQUATIC ORGANISMS
AROMATICS
BODY
CELL DIVISION
CONDENSED AROMATICS
DIGESTIVE SYSTEM
DISEASES
GLANDS
ORGANIC COMPOUNDS
ORGANS
PATHOGENESIS
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology