Efecto de la restricción alimentaria sobre el crecimiento somático en el pez cíclido Cichlasoma dimerus

FOSSATI, MARIANA; PEREZ SIRKIN, DANIELA; DELGADÍN, TOMÁS; VISSIO, PAULA; CÁNEPA, MAXIMILIANO

Ciudad Autónoma de Buenos Aires

Jornada; X JORNADAS ANUALES DE LA SOCIEDAD ARGENTINA DE BIOLOGÍA; 2010

Sociedad Argentina de Biología

Fish can withstand long periods of food restriction, by modulating the expression of different factors associated with growth hormone (GH) / insulin-like growth factor-I (IGF-I) system. If food is limited, energy is used for essential physiological processes and a reduction in growth can be observed. However, little is known about the mechanisms involved in these processes. The aim of this study was to determine in this specie if fasting affects somatic growth, and GH /IGF-I expression. Fish were divided in two groups. The first was fasted for 21 days and the second continued to be fed (control group). During this period the weight and length were recorded twice a week. After this time they were sacrificed, previous blood extraction and pituitary and liver sampled in order to analyze the GH and IGF I mRNA levels respectively by RT-PCR. Results shown a significant reduction in somatic growth (P / L * 100) and in the hepatosomatic index in fasted animals. There were no differences in cortisol levels between the two groups. The fasted animals shown a significant reduction in IGF mRNA levels, but no difference in GH mRNA levels was observed. These results suggest that fasting affects somatic growth probably acting on GH / IGF-I at different levels.