The action of chlorpromazine upon the serum and hypophyseal levels of prolactin and TSH in the pinealectomized male rat.

The action of chlorpromazine (CPZ) administered intraperitoneally (i.p.) in a single dose of 1.0 mg (0.2 ml) upon the serum and hypophyseal levels of prolactin and TSH was investigated in sham-operated (Sh-O) and pinealectomized (Px) male rats. Fourteen days after surgery the animals received 0.2 ml of CPZ or 0.2 ml of isotonic natrium chloride solution and were killed one hour after. The following data were obtained: a) CPZ released pituitary prolactin in both Sh-O and Px groups; b) The TSH circulating levels were increased in the Px group receiving CPZ (p less than 0.01); however, the same sense of variation was observed also in the Sh-O group. The results are suggesting the lack of intervention of the pineal in the mechanism of action of CPZ on the pituitary hormones with or without target gland.