Differential Dose‐dependent Effects of α‐, β‐Carotenes and Lycopene on Gap‐junctional Intercellular Communication in Rat Liver in vivo
- 1 December 1997
- journal article
- Published by Wiley in Japanese Journal of Cancer Research
- Vol. 88 (12) , 1121-1124
- https://doi.org/10.1111/j.1349-7006.1997.tb00338.x
Abstract
In order to examine the relevance of alteration of gap‐junctional intercellular communication (GJIC) to chemopreventive activity against carcinogenesis, the effects of α andβ ‐carotene as well as lycopene, typical chemopreventive carotenoids, on cell coupling via gap junctions in rat liver in vivo were studied using a direct functional dye‐transfer technique. We found that all three test compounds given at a dose of 50 mg/kg‐body weight (b.w.) daily, 5 times by gavage, inhibited GJIC, while similar treatment with 5 mg/kg b.w. caused enhancement, especially in the β‐carotene and lycopene‐treated groups. At the dose level of 0.5 mg/kg b.w., the three compounds had no effect. The findings show that all three agents differentially modulate GJIC depending on the dose, with beneficial effects on cell communication only detected at the one dose. The result suggests that determination of the dose of chemicals to be used is crucial for human intervention studies.Keywords
This publication has 35 references indexed in Scilit:
- Cx32 gene mutation in a chemically induced rat liver tumourCarcinogenesis: Integrative Cancer Research, 1996
- Effects of a Combination of Beta Carotene and Vitamin A on Lung Cancer and Cardiovascular DiseaseNew England Journal of Medicine, 1996
- Retinoic acid enhances connexin43 expression at the post‐transcriptional level in rat liver epithelial cellsCell Biochemistry and Function, 1995
- Intercellular communication may facilitate apoptosis: Implications for tumor promotionMolecular Carcinogenesis, 1994
- Altered homologous and heterologous gap‐junctional intercellular communication in primary human liver tumors associated with aberrant protein localization but not gene mutation of connexin 32International Journal of Cancer, 1994
- Endogenous and exogenous modulation of gap junctional intercellular communication: Toxicological and pharmacological implicationsLife Sciences, 1993
- Cell‐cell communication and growth control of normal and cancer cells: Evidence and hypothesisMolecular Carcinogenesis, 1993
- Retinoic acid modulates gap junctional permeability: A comparative study of dye spreading and ionic coupling in cultured cellsExperimental Cell Research, 1991
- Sequential changes of gap-junctional intercellular communications during multistage rat liver carcinogenesis: direct measurement of communication in vivoCarcinogenesis: Integrative Cancer Research, 1991
- Growth inhibition of transformed cells correlates with their junctional communication with normal cellsPublished by Elsevier ,1986