ÜBER DIE ANTAGONISTISCHE WIRKUNG VON TRIJODTHYRONIN UND PROGESTERON AUF DEN PREDNISOLONEFFEKT AM EPIPHYSENKNORPEL (PRÜFUNG DER REISSFESTIGKEIT)

Abstract

ABSTRACT Longitudinal tension exerted on a killed rat's femur results always in rupture on the same place viz: the distal epiphyseal line. The power required to produce this effect can be measured with a simple dynamometer. The tensile strength increases with advancing age and during exsiccation (thirst). In untreated rats (weight range 100–120 g) this value amounts to about 1.5–1.8 kg. Tensile strength of the femoral epiphyseal line may be influenced by hormones. Corticosteroids such as prednisolone acetate and cortisol acetate increase the level of maximal load to more than 2.0 kg. In general the effect of a single injection reaches a climax after 48 hours. Dose-response-curves can be established and relative effectiveness may be gathered therefrom. Deoxycorticosterone acetate likewise increases tensile strength in spite of the fact that contrary to prednisolone exhibiting diuretic action this compound has a water retaining effect. Triiodothyronine and progesterone when given alone produce a slight decrease in tensile strength. The effect of prednisolone when given simultaneously with one of these two compounds is antagonized: this phenomenon is more pronounced in the case of triiodothyronine.