Substance P-like immunoreactive nerve fibers in the pars distalis of the adenohypophysis of macaque monkeys.

A substantial number of substance P-like immunoreactive nerve fibers were found in the anterior pituitary of macaque monkeys. Most of them were thin fibers with abundant varicosities, which were often in close proximity to the glandular cells. They were found only in the median part of the gland and were distributed chiefly in its dorso-posterior region.