Metabolic modulation in Labeo rohita fingerlings during starvation: Hsp70 expression and oxygen consumption

An experiment was conducted to study the metabolic modulation of Labeo rohita fingerlings (mean wt. 3.75 g) during starvation in terms of heat shock protein (Hsp70) expression in liver and muscle tissues and oxygen consumption rate. Hsp70 expression and oxygen consumption were measured following starvation of 0, 1, 2 or 3 weeks for the respective groups. The quantity of Hsp70 in liver increased linearly (y = 1.837x − 2.43; R2 = 0.91) with the duration of starvation; but it was undetectable in the control group (no starvation). Though Hsp70 was expressed in muscle, only 3-week-starved fish exhibited a significantly higher (p < 0.05) quantity of Hsp70 than the other groups. A decline in oxygen consumption was also observed in the feed deprived fingerlings suggesting that the fish are capable of adjusting their metabolic rate by reducing oxygen intake during starvation. An inverse relationship was observed between the magnitude of Hsp70 elevation and the oxygen consumption (y = − 11.237x + 161.08; R2 = 0.89), suggesting that both Hsp70 and reduced oxygen consumption act to protect the fingerlings against the starvation stress. This prima facie report on carp suggests that enhanced Hsp70 expression and reduced metabolic activity are two important strategies adapted by L. rohita fingerlings to overcome the stress due to starvation.