La radiothyroïdectomie et son effet sur la consommation d'oxygène chez les cichlidés Aequidens latifrons

Abstract

The thyroidectomy produced after radioiodide immersion of the cichlid fish Aequidens latifrons during 5 months was characterized by progressive alterations of the thyroid tissue from the disappearance of colloid, the degeneration of thyroid cells until an intensive proliferation of fibrous tissue, which replaced the thyroid follicles of the gland. Autoradiographic examinations revealed a few microfollicles, which presented a small activity.The consequential effects on the respiratory exchanges are significant decreases of the oxygen consumption which are progressive and more important than the decreases obtained after thiourea treatment. The decreases reach a third of the normal rate of oxygen consumption, 32% after a long treatment period (150 days). This proves the relationship between the thyroid gland and the oxygen consumption of fishes.