Here you go
======================================
J Clin Endocrinol Metab 1976 Mar;42(3):603-6
Effect of pyridoxine on human hypophyseal trophic hormone release: a possible stimulation of hypothalamic dopaminergic pathway.
Delitala G, Masala A, Alagna S, Devilla L.
A single dose of pyridoxine (300 mg iv) produced significant rises in peak levels of immunoreactive growth hormone GH and significant decrease of plasma prolactin PRL in 8 hospitalized healthy subjects. Serum glucose, luteinizing hormone LH, follicle stimulating hormone FSH and thyrotropin TSH were not altered significantly. In addition, in 5 acromegalic patients who were studied with both L-dopa and pyridoxine, inhibition of GH secretion followed either agent in a similar pattern. These data suggest a hypothalamic dopaminergic effect of pyridoxine.
===============================
N Engl J Med 1982 Aug 12;307(7):444-5
Pyridoxine (B6) suppresses the rise in prolactin and increases the rise in growth hormone induced by exercise.
Moretti C, Fabbri A, Gnessi L, Bonifacio V, Fraioli F, Isidori A.
=====================================
Boll Soc Ital Biol Sper 1984 Feb 28;60(2):273-8
[Influence of administration of pyridoxine on circadian rhythm of plasma ACTH, cortisol prolactin and somatotropin in normal subjects]
[Article in Italian]
Barletta C, Sellini M, Bartoli A, Bigi C, Buzzetti R, Giovannini C.