Cerebrospinal Fluid Prolactin Concentrations Research Articles

The uncoupled couple? Prolactin and CD4 lymphocytes in HIV infection

The possible role of prolactin (PRL) in human immunodeficiency virus (HIV) infection is unknown, despite the modulatory role of this hormore in humoral and cell-mediated immune responses. Recent studies have evidenced: (a) intralymphocyte synthesis of dopamine (DA) which down-regulates their own proliferation and differentiation; (b) decreased DA but increased PRL concentrations in cerebrospinal fluid of HIV-infected men; and (c) diminished hypothalamic DA tone in HIV-infected men.The present hypothesis proposes that, in HIV-infected men, a diminished generalized DA tone exists to stimulate human lymphocyte proliferation and differentiation at a maximum possible rate by: (1) decreasing the inhibitory influence of intralymphocyte DA; and (2) maintaining pituitary and extrapituitary (i.e. lymphocyte) PRL synthesis and release as high as possible. If this hypothesis is correct, it may have a potentially important therapeutic implication: the possibility to rebuild the battered immune system in HIV-infected patients from inside the body in a physiologic manner by the parenteral administration of recombinant human PRL.

Effects of advancing age on cerebrospinal fluid concentrations of prolactin in the female rat

Studies were conducted to determine the effects of advancing age on serum and cerebrospinal fluid (CSF) prolactin (PRL) concentrations in the female rat. In young rats with basal serum PRL levels, CSF PRL was maintained at 1.1–2.1% of serum PRL levels. In middle-aged rats, CSF PRL levels and the ratio of CSF to serum PRL was low in rats which maintained estrous cycles, but was increased 4- to 10-fold in rats which were in constant estrus. In aged constant estrous rats, CSF PRL concentrations were increased markedly and the CSF to serum PRL ratio increased to 31%. Collectively, these data indicate that (i) in young female rats, only a fraction of serum PRL reaches the CSF; (ii) that CSF PRL concentrations are low in middle-aged rats which exhibit estrous cycles and (iii) that aging and the constant estrous state are associated with elevated CSF PRL concentrations. As such, the age-related elevation in serum PRL levels and the fraction of PRL which accumulates in the CSF may contribute to the age-related dysfunction in brain PRL-responsive neurons.

Effects of haloperidol and prolactin secreting tumors on cerebrospinal fluid concentrations of prolactin in the female rat

Studies were conducted to determine the effects of acute and chronic elevations in prolactin (PRL) secretion on serum and cerebrospinal fluid (CSF) PRL concentrations in the female rat. Young female rats showed a dose-dependent increase in serum and CSF PRL in response to haloperidol. A time-course evaluation of serum and CSF PRL levels after haloperidol indicated that serum PRL concentrations increased markedly by 30 min and declined thereafter; while CSF PRL increased more slowly, peaking at 2 to 8 h. In young rats with basal serum PRL levels, CSF PRL was maintained at 0.8 to 2.1% of serum PRL levels. During acute hyperprolactinemia, the CSF to serum PRL ratio increased to about 4%. During chronic severe hyperprolactinemia, induced by the growth of a MtT·W15 tumor, CSF PRL concentrations increased to 75 ng/ml, but this represented only 1.5% of serum PRL concentrations. Collectively, thse data indicate that the blood-brain barrier effectively limits access to the brain of circulating PRL.

The relationship between blood and cerebrospinal fluid prolactin in nonhuman primates

We studied the relationship between plasma and cerebrospinal fluid (CSF) concentrations of prolactin (PRL) in repeated and simultaneous samples of blood and CSF from chair-restrained rhesus monkeys. Following administration of thyrotropin releasing hormone (TRH), each of 4 monkeys showed increased plasma and lumbar CSF PRL concentrations. Increases in CSF PRL concentrations were muted and delayed until 60 min after peak plasma concentrations were attained. In 3 other monkeys we compared PRL concentrations in simultaneous lateral ventricular and lumbar CSF samples. Although we found no difference in PRL concentrations under baseline conditions, a ventricular-lumbar PRL concentration gradient became apparent after TRH stimulation. These studies demonstrate that changes in plasma PRL concentrations are reflected in CSF concentrations. They suggest that a significant blood-CSF barrier exists for PRL and that PRL may enter the the CSF selectively via the ventricles.

Anterior pituitary hormone levels in the cerebrospinal fluid of patients with pituitary and parasellar tumors

Cerebrospinal fluid (CSF) concentrations of growth hormone, prolactin (PRL), adrenocorticotropin, thyroid-stimulating hormone, follicle-stimulating hormone, luteinizing hormone, and the glycoprotein hormone alpha subunit were determined in 30 patients with pituitary and parasellar tumors. Although many of the patients had elevated hormone levels, no differentiation between patients with intrasellar tumors and those with pituitary tumors with suprasellar extension or primary suprasellar tumors could be made based upon the absolute CSF hormone concentration. A highly significant correlation between serum and CSF PRL concentrations was found (r = 0.87; P less than 0.001), suggesting that CSF PRL is derived from the serum. No correlation was found between the serum and CSF concentrations of the other anterior pituitary hormones.

Homogeneous distribution of prolactin in human cerebrospinal fluid

Concentrations of prolactin were assayed from human cerebrospinal fluid (CSF). Samples were taken from lumbar CSF space (n=105 neurological patients) and from lateral ventricles (n=31 neurosurgical patients). Ventricular CSF samples were taken from operatively treated subarachnoidal hemorrhage (SAH) patients during the monitoring of intraventricular pressure. More voluminous and frequent sampling was obtained from six patients undergoing diagnostic pneumoencephalography (PEG) procedure. Prolactin concentrations in lumbar CSF ranged between undetectable and 2.8 ng/ml with a mean value of 0.78±0.54 (SD) ng/ml. Some fluctuation was seen in the fractionated samples taken at PEG, but no definitive gradient was noticed. Ventricular CSF concentrations of prolactin (n=18) were 0.85±0.67 (SD) ng/ml at operation (range : undetectable − 2.5 ng/ml). Somewhat lower values were recorded in the 3-day postoperative period, prolactin mean concentrations being 0.3 − 0.6 ng/ml. The CSF prolactin concentrations in the lateral ventricles and lumbar sac are practically identical with no concentration gradient between these compartments.