Attempt to Modify Growth,Development and Tumor Incidence in Mice with Thymus Gland Extracts

Summary

Thymus gland extract was without stimulating effect on growth or development in Line A albino mice when injected in doses of 0.5 cc 3 times weekly from the time of weaning throughout the reproductive period. A marked lowering of fertility occurred in the second generation from treated parents and grandparents. There were only 3 third-generation females and these were sterile. This unexpected decrease in fertility resulted in too small a number of females surviving to tumor age to permit any conclusions as to the effect of thymus extract upon tumor incidence other than that it did not prevent their appearance or affect their growth.

ρ-Thiocresol was without effect on fertility, growth or development of Line A albino mice and did not modify the occurrence of spontaneous tumors. It did not influence the growth of inoculated tumors.