Relationships between biotin and DNA contents and DNA turnover in lymphoid organs: thymus, lymph nodes and spleen.

Biotin-deficient rats show a slower growth rate and a reduction in thymus, intestinal lymph nodes and spleen weight. The effect is reversible. Biotin administration to normal rats (1 mg/rat/day) causes an increase in intestinal lymph nodes and spleen, while there is no effect on body and thymus weight. The amount of thymus and spleen DNA is lower for deficient than control rats. No difference was noticed between the levels of DNA from normal control and biotin-deficient rat lymph nodes, and between the levels of DNA from normal rats treated and untreated with biotin. The time-course of the specific radioactivity of DNA and the DNA turnover shows that biotin increases both the incorporation of labelling in DNA and DNA turnover rate.