Effect of Bilateral Adrenalectomy on the Thymo-lｙmphatic Tissues (Observations in Young and Senile Albino Rats)

There have been a number of reports indicating that adrenalectomy induces a hyperplasia of the thymolymphatic tissues＾1-12). The present study was undertaken to provide further date on hyperplasia and regeneration of the thymus and other lymphoid organs following bilateral adrenalectomy in young and senile albino rats. Male and female rats of randomly bred Wister strain were used as material. These animals were bred in our laboratoty under optimal environmental conditions. Young rats of 1 and 2 months of age and senile rats of 18 months of age were divided into two groups : One group was bilaterally adrenalectomized and other kept as control. Adrenalectomized group was given 1% saline as drinking water. Young group animals were autopsied after 30 days and senile group animals after 12-15 days of the adrenalectomy. A total of 80 animals was subjected to adrenalectomy and only 18 survived throughout the period studied (tables 1-8). The thymus, mesenteric lymph nodes and spleen were removed from these animals, weighed on a torsion balance, and then the total number of nucleated cells in individual organs was estimated by the method described by Awaya et al. in 1962. At the same time, histological studies of section were also made of these organs. Thus, the effect of the adrenalectomy on the thymolymphatic tissues was observed from both the quantitative and histological views.