SHORT TERM FASTING AND IMMUNE SYSTEM FUNCTION IN THE BROAD SNOUTED CAIMAN, Caiman latirostris

LOPEZ-CATIVA, LEANDRO; MOLINA-MARIANAO, LUCIANA; GONTERO FOURCADE, M. N.; CAVIEDES VIDAL, E.

San Francisco, California

Congreso; Society for Integrative and Comparative Biology with the Animal Behavior Society American Microscopical Society The Crustacean Society; 2013

Society for Integrative and Comparative Biology with the Animal Behavior Society American Microscopical Society The Crustacean Society

SHORT TERM FASTING AND IMMUNE SYSTEM FUNCTION IN THE BROAD SNOUTED CAIMAN, Caiman latirostris Caimans experience different environmental pressures during their life, such as decreased availability of food resources. Since a reduction of energy intake at early ages may result in a trade-off between growth and immune function, we studied immune, metabolic and stress parameters of young caimans subjected to short term fasting. Fifteen 8-month old caimans were divided in 2 gropus: A) with food ad lib (F+, N=8) B) fasted (F-, N=7) for 60 days. Blood was collected to perform the following assays: whole blood for hematocrit and heterophil/lymphocyte (H/L) index; plasma for biochemical parameters, total IgG (humoral immunity) and complement hemolytic activity (CHA) (innate immunity); blood cells for Heat Shock Protein 60, 70 and 90 (HSPs) (stress biomarkers) assessment. After fasting, the F- group lost 12% of their initial body-mass versus a 5% loss of the F+ group. Hematocrit and H/L index were not different between treatments. The four biochemical parameters showed significant differences between groups. No differences were apparent for the IgG index, though CHA exhibited a decreasing trend in fasted caimans. None HSPs analyzed showed differences in their expression levels. These results show that even after a significant period of fasting that alters their metabolic status, young growing-caimans can endure an energy shortage without altering their immune parameters. This is a key fact for survival considering they must face highly pathogenic environments and food scarcity in nature. Funded by PICT97-01320 to EC-V.