[Comparative action of L-dopa and bromocriptine on thyreostimulating hormone (T.S.H.) in primary hypothyroïdism...

The comparative action of fixed I-dopa (500 mg orally) and bromocriptine (2,5 mg orally) doses on T.S.H. of 20 patients (8 men and 12 women) with primary hypothyroïdism was studied. T.S.H. was significantly decreased from first hour with I-dopa (p less than 0.005) and the greater decrease was reached at the second hour. T.S.H. was the thereafter progressively increased and was like basal value at the fifth or the sixth hour of the test. T.S.H. was likewise significantly decreased from first hour with bromocriptine (p less than 0,01), but the decrease was progressive during the six hours and the greater decrease was reached at the sixth hour (p less than 0,005). The decreased T.S.H. was greater for woman than for man as much with I-dopa (p less than 0,005), as with bromocriptine (p less than 0,002). The greater decrease was the same with I-dopa or bromocriptine. These results were comparatively discussed with others. They favoured an inibiting action of dopaminergic axis on T.S.H. secretion in primary hypothyroïdism.