Thymo-adrenals reaction in pre-pubertal and pubertal Wistar rats in response to acute administration of calcitonin

Pre- and post-pubertal Wistar rats were injected i.m. with a single dose equivalent to 1 UI of Calcitonin (Calsyn-50 Rorer, Swiss). Its effects upon the thymus and adrenals were assessed after 1, 3 and respectively, 8 days since injection. The results pointed to differences of reaction of the thymus and adrenals dependent on rat ages and on the period of hormone persistence in the organism. The effects in mature rats are characterized by a stress state, reflected in adrenal reaction, but without impact upon the thymus in point of biochemical parameters. In rats of that age, modifications in both organs are much reduced after 8 days since calcitonin injection. In pubertal rats, adrenal activity is temperate, and thymus registers modification of DNA, of oxygen consumption and of nitrogen aminic after 3 days since injection. This modification is maintained for 8 days.