RESUMO
1. Tissue- and species-specificity of the electrophoretic patterns of the multiple molecular forms of esterases were observed in the urodele amphibians Mertensiella luschani luschani, M.l. helverseni and Salamandra salamandra. All esterases--distributed into two electrophoretic mobility areas in gonads, muscles and brain and into four areas in liver, stomach and intestine--were characterized as carboxylesterases. 2. M. l. luschani and S. salamandra liver esterases were electrofocused into nine and eleven major bands with pIs ranging from 4.60 to 5.65 and from 4.40 to 6.20, respectively. 3. Two size groups of esterases were observed in liver extracts of the above three subspecies by Sephadex G-200 gel filtration. The mean values of their apparent molecular weights were 70,000 and 230,000 respectively.