Comparison of Plasma Dipeptidyl Peptidase IV (DPPIV) Activity in Two Caiman Species: Caiman latirostris and Caiman yacare (Crocodilia, Alligatoridae)

SIROSKI, P.A., M.E. MERCHANT, M.V. PARACHÚ MARCÓ, G.L. POLETTA, H.H. ORTEGA.

ANIMAL BIOLOGY

BRILL ACADEMIC PUBLISHERS

Lugar: Leiden, the Netherlands; Año: 2011 vol. 61 p. 199 - 210

1570-7555

Dipeptidyl peptidase IV (DPPIV) is a well-characterized protease with broad substrate specificity, functionally-related to the activity of many bioactive peptides. It plays an important role as physiological regulator of a number of peptides that serve as biochemical messengers within the immune system. Plasma DPPIV activity was characterized with respect to temperature, kinetics and concentration dependence in two species of caiman, the broad-snouted caiman (Caiman latirostris) and the black yacare (Caiman yacare). DPPIV activity showed a significant positive correlation from titrations carried out in the presence of different plasma concentrations. DPPIV activity was lower in black yacare than in broad-snouted caiman at all temperatures tested. Black yacare DPPIV activity showed significant increase only at higher temperatures while in the broad-snouted caiman plasma it demonstrated a strong positive correlation starting at the lowest temperature, probably due to an adaptation for the toleration of lower temperatures. Exposure of C. latirostris and C. yacare plasma at different time points showed that plasma DPPIV activities were time-dependent, and that the titer-dependent curves were different for the two species. These results revealed that plasma DPPIV activities were different between these two crocodilian species, which could be one of the reasons for the differences in susceptibility to infection in them.