Hyperprolactinemia: pathophysiology and therapeutic approach

Abstract

Prolactin (PRL) is a hormone, mainly secreted by lactotroph cells of the anterior pituitary gland. Recent studies have shown it may also be produced by many extrapituitary cells. Its well-recognized PRL plays an important role in lactation during pregnancy, but it is involved in other biological functions such as angiogenesis, immunoregulation and osmoregulation. Hyperprolactinemia is a typical condition producing reproductive dysfunction in both sexes, resulting in hypogonadism, infertility and galactorrhea. It may be also asymptomatic. Lactotroph adenomas (prolactinoma) is one of the most common cause of PRL excess, representing approximately 40% of all pituitary tumors. Several other conditions should be excluded before a clear diagnosis of hyperprolactinemia is made. Hyperprolactinemia may be secondary to pharmacological or pathological interruption of hypothalamic-pituitary dopaminergic pathways or idiopathic. Stress, renal failure or hypothyroidism are other frequent conditions to exclude in patients with hyperprolactinemia. We will review biochemical characteristics and physiological functions of that hormone. Clinical and pharmacological approach to hyperprolactinemia will also be discussed.

Hyperprolactinaemia

“…Secretion of PRL by the pituitary gland has a circadian rhythm with higher levels during sleep and lower during wakefulness [6]. Increased concentrations are also seen during ovulation [9]. Synthesis and secretion of PRL is regulated through both inhibiting and releasing factors [8].…”

Genetic and Hormonal Determinations in a Pair of Identical Twins with Early Onset Psoriasis Vulgaris: Case Report and a Brief Review of the Literature

“…The number of neutrophils and Th1 cells is reduced and, at the same time, the production of TNF alpha is inhibited (16). On the other hand, abnormal values of estrogen may be a cause of hyperprolactinemia (17).…”

Prolactinoma: Etiological, Diagnostic and Therapeutic Aspects

“…При диагностике выявляется частичный или полный гипопитуитаризм у 78 % мужчин с макропролактиномами; происходит поражение осей: гонадотропной (74 %) и соматотропной (31 %) тиреотропной (25 %) и кортикотропной (23 %) [2,4,6,30]. У женщин первые клинические признаки макропролактиномы чаще (∼70 %) связаны с гормональной дисфункцией (олигоменорея, аменорея, бесплодие и галакторея) [2,4,6,12,30]. Если типичные симптомы гиперпролактинемии отсутствуют, следует заподозрить макропролактинемию.…”