A study of thyrotropin stimulated 131I release in vitro by thyroid glands obtained from normal and protein deficient rats

The role of anterior pituitary in regulation of thyroid function in protein malnutrition has been investigated in normal and protein deficient rats by an indirect TSH assay method. The release of 131I from the prelabeled thyroid glands was studied in the in vitro model. Exogenous TSH was added to the system in two selected doses and the release was followed for the next 30 minutes. The results indicate a progressive release of radioiodine from the thyroid gland in both the groups. The resting release is significantly enhanced by the addition of TSH to the system. The increase in release was almost to the same extent in the two groups. Thus, the thyroid from the protein deficient rat responds normally to TSH stimulation in the in vitro system. The higher dose of TSH inhibited the release of 131I to some extent, as compared to its one-tenth dose.