THE INFLUENCE OF PREGNANCY, HYPERVITAMINOSIS-D AND PARTIAL NEPHRECTOMY ON THE VOLUME OF THE PARATHYROID GLANDS IN RATS

Abstract

The significance of the 3 factors to which hyper-plasia of the parathyroid glands is ascribed in the literature was tested experimentally in 52 rats, divided into 6 groups. The groups were subjected to no treatment, partial nephrectomy, hypervitaminosis-D, pregnancy, nephrectomy and hypervitaminosis-D, and nephrectomy and pregnancy, respectively. Partial nephrectomy was associated with a statistically reliable increase in parathyroid volume in rats not otherwise treated (165%, C.R. 3.78) as well as in groups which were also made hypervitaminotic (158%, C.R. 2.53) or pregnant (61%, C.R. 3.4). Pregnancy alone was associated with a fairly significant increase in parathyroid volume (40.5%, C.R. 2.83). Hypervitaminosis-D alone in rats was associated with a statistically unreliable increase in parathyroid volume (31.5%, C.R. 1.77). Within the nephrectomized groups, there was no significant difference between the group not otherwise treated and either that given vit. D or made pregnant (C.R. 0.84 and 0.78). A summation effect of 2 factors, renal damage and pregnancy, each capable of producing hyperplasia of the parathyroids, was not apparent.