Effects of four inorganic lead compounds on the proliferation and junctional coupling of cultured REL liver cells.
BACKGROUND
Chronic, low-level exposure to inorganic lead (Pb) has been involved in a number of human diseases, including tumors. In this study, the effect of four different inorganic Pb compounds (acetate, chloride, monoxide, and sulfate) was evaluated, in vitro, on liver-derived REL cells, known to be very sensitive to tumor promoters.


METHODS
Cytotoxicity and effects on intercellular communication (GJIC) were evaluated, respectively, by cell- density/proliferation and dye-transfer assays. Pb concentration in the media solutions used for each treatment was quantified by atomic absorption spectroscopy-electrothermal atomization.


RESULTS
Each of the Pb compounds we tested showed a typical dose- and time-related effect on REL cell proliferation, this effect not being related to the free metal concentration. Contrary to classical tumor promoters, none of the compounds significantly affected REL GJIC (1-hour treatment).


CONCLUSIONS
Our results are indicative of specificity in the effects of the different Pb compounds. The mechanism(s) of their action need further investigations.
Institute of Occupational Health, School of Medicine, University of Brescia, Brescia, Italy.
P
P
Apostoli
C
C
Huard
C
C
Chaumontet
P
P
Martel
L
L
Alessio
G
G
Mazzoleni
D000818:Animals; D002273:Carcinogens / Q000009:adverse effects*; D002450:Cell Communication / Q000187:drug effects; D002452:Cell Count; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line / Q000187:drug effects / Q000473:pathology; D004848:Epithelium / Q000187:drug effects / Q000473:pathology; D007365:Intercellular Junctions / Q000187:drug effects; D007854:Lead / Q000009:adverse effects*; D008099:Liver / Q000187:drug effects* / Q000473:pathology*; D009942:Organometallic Compounds / Q000009:adverse effects; D010087:Oxides / Q000009:adverse effects; D051381:Rats
D002273:Carcinogens; D009942:Organometallic Compounds; D010087:Oxides; D007854:Lead; C029891:lead chloride; C047365:lead oxide; C032722:lead sulfate; C008261:lead acetate