Prolactin secretion and nodular goiter. (Hypothetical correlations)

In a group of 129 female patients with nodular goiter, Graves' disease and primary hypothyroidism, the PRL and TSH secretions were studied in parallel. Concurrent changes in the two hormones were evident only in conditions of marked hyper- or hypothyroidism. In the patients with non-toxic nodular (single or multiple) goiter the TSH showed low or normal values, while the PRL appeared normal or elevated. From these results two important conclusions can be drawn: 1. the T3 and T4 levels interact with PRL secretion concomitantly with TSH only when they undergo a huge deviation from the normal range; 2. the goitrogenic action of PRL that has been reported in experimental animals cannot be excluded in man.