The Action of Hanson's Thymus Extract on the Mouse

Hanson's study on the effects of thymus gland extracts in albino rats demonstrated significant acceleration in growth and morphological differentiation. The study involved daily injections of thymic extract over four generations, starting from the 16th day of life and continuing through pregnancy. Results showed faster growth, earlier development of hair, teeth, and sensory organs, and earlier sexual maturation compared to controls. The most pronounced effects were observed in the F2 generation, with continued, albeit slight, increases in subsequent generations. Notably, the time for vaginal opening was reduced from 60-70 days in controls to 18-19 days in the F4 generation, and hair appearance was accelerated from 14-17 days to the 3rd day.