The effect of lithosperm on thyroidal 32P uptake at various times of injection

These experiments were performed to increase our understanding of possible side effects in the use of extracts of the plant Lithospermum ruderale (LSPM) as a contraceptive. Cold-water extracts of LSPM were used to note possible effects on injected TSH and on endogenous TSH which was increased by the use of propylthiouracil. It was demonstrated that LSPM had a biphasic effect on both endogenous and exogenous TSH activity as measured by chick thyroid 32P uptake. When given 18h before autopsy, LSPM decreased TSH activity in both, whereas when LSPM was administered 42h or 44h before autopsy, TSH activity was significantly increased.