Pyridoxine and depression: neuroendocrine aspects

Plasma prolactin levels (PRL) were determined in 5 male depressed patients and in 5 controls, after injection of TRH (200 mg i.v.) (first phase), TRH following oral L-DOPA (500 mg) given 90 minutes before (second phase), TRH plus pyridoxine (300 mg i.v.) after same pretreatment with L-Dopa (third phase). L-Dopa induced a statistically significant suppression of TRH, caused PRL release; such suppression appears to be lower when TRH plus pyridoxine were administered simultaneously. PRL profile was not significantly different in the two groups.