Abstract
It has been shown that d , l-thyroxine has an inhibitory effect on wound healing. The present study attempts to elucidate whether that effect is a direct one on tissues or is mediated by changes in the release of pituitary hormone. The dextro-isomer brought about an increase in the tensile strength of healing wounds in guinea pigs. D-thyroxine seems, therefore, to inhibit the hormone release from the thyroid gland by depressing the pituitary gland. The inhibitory effect of d , l-thyroxine on wound healing must be brought about by some peripheral factors.