Figure 2.

Growth (mean ± sem) in body mass, tail length, tibial length, organ (heart, liver, and kidney) mass, and organ mass relative to body mass during and after PTU treatment in young rats. Female rats (open symbols) were made hypothyroid by adding PTU to the drinking water from birth until 8 wk of age. Untreated animals served as controls (closed symbols). All rats received depot leuprolide acetate every 6 wk, starting at 3 wk of age. During the PTU treatment period (solid boxes, pertains to all graphs), growth was inhibited in treated animals (P < 0.001 for body mass, tail length, tibial length, organ masses). Afterward, catch-up growth occurred in all of those measures (defined as growth rate greater than controls, P < 0.001), although the catch-up was not complete at the time of the final measurement (P < 0.001).