Plasma B-esterase and glutathione s-transferase activities in the South American reptiles Caiman latirostris

• Published in: Water, air, and soil pollution air, and soil pollution, 2012-07, Vol.223 (6), p.3321
• Main Authors: Attademo, Andres M, Lajmanovich, Rafael C, Peltzer, Paola M, Basso, Agustin, Junges, Celina, Cabagna-Zenklusen, Mariana
• Format: Article
• Language: English
• Subjects: Glutathione transferase; Pesticides; Turtles; Zoos
• ISSN: 0049-6979
• DOI: 10.1007/s11270-012-1112-x

We determined normal plasma butyrylcholinesterase (BChE), carboxylesterase (CbE using [alpha]-NA substrate), and glutathione S-transferase (GST) activities in Caiman latirostris and Phrynops hilarii to obtain reference values for organophosphorus (OP) pesticide monitoring. BChE and CbE sensitivity to malaoxon was also evaluated. C. latirostris (N= 12; six males and six females) -and P. hilarii (N= 12; seven males and five females) were obtained from the programs Yacare (Entre Rios Province, Argentina) and Zoo of Cordoba (Cordoba Province, Argentina). Mean total (female and male) plasma BChE activity was significantly different between reptile species, ranging between 0.337[+ or -]0.085 [micro]mol [min.sup.-1] [ml.sup.-1] of plasma for C. latirostris and 0.251 [+ or -]0.070 [micro]mol [min.sup.-1] [ml.sup.-1] of plasma for P. hilarii. However, plasma CbE ([alpha]-NA) and GST activities were significantly higher in P. hilarii (4.81 [+ or -]1.00 and 0.145[+ or -]0.045 [micro]mol [min.sup.-1] [ml.sup.-1] of plasma, respectively) than in C. latirostris (0.57[+ or -]0.20 and 0.059 [+ or -]0.013 [micro]mol [min.sup.-1] [ml.sup.-1] of plasma, respectively). No significant differences in B-esterase and GST activities were detected between sexes, except CbE ([alpha]-NA) for C. latirostris. [IC.sub.50] values for BChE and CbE ([alpha]-NA) suggested different sensitivity levels between species and between sexes. The results demonstrate that plasma esterase activity varied between species, but not between sexes (except CbE for C. latirostris). The in vitro inhibition tests indicated that CbE ([alpha]-NA) is more sensitive to inhibition than BChE. C. latirostris may be the reptile species most vulnerable to field pesticide exposure because this reptile presents the lowest CbE activity levels and its B-esterase levels seem more sensitive to OP. Keywords B-esterases * Glutathione S-transferase * Malaoxon * Caiman latirostris * Phrynops hilarii