Pituitary Hormone Concentrations in Cerebrospinal Fluid in Patients with Pituitary Tumors

Abstract

Adenohypophyseal hormones are frequently detectable in the cerebrospinal fluid (CSF) of patients with pituitary adenomas,1–9 especially those showing suprasellar extension (SSE).4,6,7 However, documentation of their presence in CSF of normal subjects is controversial. Some workers readily find anterior pituitary hormones in CSF,10,11 while others do not.1,4,6,7,9 It has been proposed that in the normal individual, the blood-brain barrier (BBB) is relatively impermeable to the anterior pituitary hormones and that measurable levels of these substances in the CSF of patients with pituitary tumors indicate a breakdown in the blood—CSF barrier.4,5,8 However, the possibility that adenohypophyseal hormones are normal constituents of CSF, though present below the limits of sensitivity of available assays, is not excluded. Evidence in favor of this view is provided by studies from Linfoot et al.,7 who reported that growth hormone (GH) levels in CSF of acromegalic patients without SSE correlated with the height of the plasma concentration of GH. Similar findings have also been reported for prolactin (PRL).12