Specificity of the "tibia test" in intact immature female rats.

Abstract

SUMMARY The effect of hormones on the 'tibia test' in intact immature female rats has been studied. It was found that corticotrophin, hydrocortisone, dexamethasone, oestradiol, thyroidectomy and pancreatectomy inhibit the growth of epiphysial cartilage, while somatotrophic hormone (STH) and, to a lesser extent, insulin, testosterone, thyroxine, triiodothyronine and aldosterone stimulate it. Dehydroepiandrosterone, progesterone, deoxycorticosterone and prolactin did not affect cartilage growth. Consequently, the 'tibia test' in intact immature female rats can only be considered specific for STH if interference with cartilage growth by the above mentioned hormones can be excluded. This does not detract from the usefulness of the 'tibia test' in intact female rats for studies of growth-promoting or growthinhibiting substances.