Relationship between plasma biochemistry values and metal concentrations in nesting olive ridley sea turtles

A hundred nesting olive ridley turtles were sampled to determine biochemical parameters (ALP, AST, ALT, creatinine, albumin, cholesterol, glucose, proteins, triglycerides, urea, and P-nitrophenyl acetate esterase activity). Esterase activity (EA) is a new biomarker very sensitive to metals. Most of the samples showed detectable levels. We also analyzed the concentration of 11 inorganic elements (As, Cd, Cr, Cu, Mn, Ni, Pb, Sr, Ti, Se, and Zn), some of them previously reported with very high concentrations in this population (especially cadmium with 82 and 150 μg g^-1 ww in liver and kidney, respectively). Cadmium presented two negative relationships with creatinine and glucose. Some other understudied elements, Sr and Ti, for instance, presented five and four significant relationships with some biochemical parameters, respectively (most of them positive). EA was the parameter with most negative relationships (with Pb, Ti, As, Cr, and Se), reinforcing the results of other researchers in humans regarding the possible inhibition of EA by metals.