Fig. 4. Correlation between Hsp73 and Hsp72 expression after the 24 h dive. Mean values for basal Hsp73 expression in brain (B), heart (H), liver (L) and skeletal muscle (M) are plotted relative to the dive-induced Hsp72 expression in each tissue from Fig. 3. Linear regression of the data reveals a strong regression coefficient or r² value of 0.82 and the equation y=-0.36x+33.8. These data are the mean ± S.E.M. of 16 basal Hsp73 and 20 dive-induced Hsp72 expression measurements; mean values are presented because it is not possible to obtain both measurements from the same animal.