Assay for Antistiffness Activity with Guinea Pigs Depleted on Solid Rations.

Abstract

Summary and Conclusions

Wrist stiffness was produced in guinea pigs by feeding two different commercial, pelleted rations. Both in therapeutic and in prophylactic tests, however, the untreated controls fared as well as the animals which received reputedly active supplements in amounts which have previously been shown to be more than adequate to give positive responses.^1,6 We interpret these results to indicate that (1) the mere production of wrist stiffness in guinea pigs does not necessarily yield animals satisfactory for assay purposes, that (2) the commercial, pelleted diets used by us and by Oleson et al.¹ are unsuitable as basal rations for the routine assay of the Wulzen antistiffness factor, and that (3) the activities of the steroids tested by Oleson et al. should be redetenmined with animals depleted on more satisfactory basal rations.