ACTION OF PAROTIN AND PAROTIN-LIKE SUBSTANCES UPON THE BODY-WEIGHT AND EPIPHYSEAL GROWTH OF TIBIA IN RATS

Abstract

Sialoadenectomized 60-days-old male rats of Donryu strain were administered with the high-, middle-and low-dose of parotin, E-8, an extract of bovine parotid gland containing the alpha-parotin and saliva-parotin-A (SPA) respectively for 1 week or for 6 weeks. From sialoadenectomy no influences were imposed upon the body-weight growth, but the administrations of three compounds, if the amount used was appropriate, made a slight increase in body-weight growth both of sialoadenectmized and of sham operated control rats. The administration of an appropriate dose of parotin and E-8 for 6 weeks also stimulated slightly the body-weight growth of sialoadenectmized rats, and more profoundly than in the administration for a week; while every dose of these compounds were capable to stimulate more vigorously in the control than in the operated rats. In general, SPA was inferior in exciting ability to parotin; E-8 was superior to parotin.
Histologically, sialoadenectomy did not induce any signs of atrophy in the tibial epiphysis within a week, but resulted in the atrophic pattern within 6 weeks. In rats with or without the salivary glands, the compounds could retard the postnatal involution in tibial epiphysis, especially in the primary spongiosa. This retarding action was most prominent in E-8 and most feeble in SPA. The changes in body-weight growth tended to be in parallel to the degree of atrophy in tibial epiphysis, above all in the primary spongiosa.