Tumors of the Nervous System
Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw in Hankey's Clinical Neurology, 2020
Hyperprolactinemia Women: Infertility.Amenorrhea.Galactorrhea.Reduced libido.Delayed menarche.Men: Reduced libido.Impotence.Galactorrhea – unusual.Apathy.Weight gain.
Clinical Aspects on the Role of Prolactin in Human Breast Cancer
Nagasawa Hiroshi in Prolactin and Lesions in Breast, Uterus, and Prostate, 2020
In spite of the poor prognosis of patients with hyperprolactinemia, remissions were achieved with chemotherapy or hormonal therapy. It remains to be established under which conditions and in which patients PRL inhibitors are of therapeutic value. Clinical trials have so far failed to demonstrate a significant therapeutic effect of PRL inhibitors, e.g., bromocriptine in advanced breast cancer.60,61 PRL probably modulates the effect of other hormones on tumor growth or vice versa. Ward62 noted that 14 of 36 patients with advanced breast cancer, whose disease had progressed on treatment with tamoxifen alone, subsequently responded to continued treatment with bromocriptine and tamoxifen. In another report, the combination of medroxyprogesterone acetate with bromocriptine resulted in longer remission duration than when medroxyprogesterone acetate was given alone.64
Endocrine Functions of Brain Dopamine
Nira Ben-Jonathan in Dopamine, 2020
The actions of DA on stress-induced suppression of the HPG axis are exerted at several levels, both direct and indirect. One level is at the arcuate kisspeptin neurons, which co-express D2R, the DA receptor subtype responsible for the seasonal inhibition of GnRH pulses in some species. Expression of kisspeptin and kisspeptin receptor mRNA is down-regulated by stressors such as restraint, hypoglycemia, and lipopolysaccharides, suggesting that kisspeptin signaling plays a critical role in the transduction of stress-induced suppression of reproductive processes. A second level is at the GnRH neurons. DA potently suppresses the electrical activity of GnRH neurons in both males and female rats, and a third of GnRH neurons increase basal firing rate after the administration of DA receptor antagonists, demonstrating the ability of DA for suppressing GnRH [34]. A third level is indirect, via increased PRL release. Clinical data show that hyperprolactinemia is a frequent cause of reproductive dysfunction leading to infertility in both males and females. The suppressive affects of PRL on reproduction occur at multiple sites: the hypothalamus, the pituitary, and the gonads. Serum PRL crosses the BBB and affect the Kiss1-expressing neurons where it suppresses GnRH release and, thus, the release of the gonadotropins (see further discussion in Section 4.5).
Relevance and therapeutic implication of macroprolactinemia detection using PEG 6000 in women of childbearing age with hyperprolactinemia: experience at a tertiary hospital
Published in Journal of Endocrinology, Metabolism and Diabetes of South Africa, 2023
Anne Ongmeb Boli, Martine Claude Etoa Etoga, Francine Mekobe Mendane, Charly Feutseu, Eloumba Mbono Samba, Amazia Falmata, Arnaud Manga Ndi, Jean-Claude Katte, Mesmin Dehayem, Vicky Jocelyn Ama Moor, Jean Claude Mbanya, Eugène Sobngwi
Prolactin (PRL) is a single-chain protein synthesised and released by lactotroph cells of the anterior pituitary gland.1 Its secretion is regulated by dopamine, which has an inhibitory effect on lactotroph cells.1 When prolactin secretion increases in the absence of pregnancy, clinical symptoms such as galactorrhoea and irregular menstrual cycles may occur. These menstrual abnormalities include spaniomenorrhoea and amenorrhoea, which may contribute to infertility. Hyperprolactinemia is a well-recognised hormonal aetiology of infertility among women of childbearing age. It affects 30–40% of infertile women and 15–20% of women with menstrual disorders.2 Impairment of gonadal function and, ultimately, infertility result from suppression of the pulsatile secretion of gonadotrophins.3 The majority of prolactin molecules present as monomers that are biologically active, but these may also exist as macromolecules (macroPRL) known as big and big-big prolactin, which may interfere with laboratory measurements of the protein.4 According to Vilar et al., in 2019, two Brazilian series reported macroPRL as the third cause of non-physiological hyperprolactinemia after drugs and pituitary adenomas.5 All three forms of prolactin are indistinguishable by routine laboratory assays.
Pharmacological strategies for sexual recovery in men undergoing antipsychotic treatment
Published in Expert Opinion on Pharmacotherapy, 2022
Tommaso B. Jannini, Andrea Sansone, Rodolfo Rossi, Giorgio Di Lorenzo, Massimiliano Toscano, Alberto Siracusano, Emmanuele A. Jannini
A well-established treatment protocol for a different kind of hyperprolactinemia, from prolactinoma- to AP-induced hyperprolactinemia, entails the use of dopamine agonists. The rationale behind this choice lies in the above-mentioned evidence that the dopamine tone inhibits the release of Prl in the pituitary gland. However, except for scarce data on cabergoline [189], there is no evidence that dopamine agonists may have a therapeutic effect on AP-induced SD. Indeed, molecules like bromocriptine, pramipexole, or other drugs with a dopaminergic action, such as selegiline, imipramine, and the Japanese root shakuyaku-kanzo-to were not shown to improve sexual function [190]. Only mild and preliminary findings were reported from patients treated with amantadine, whose action causes a release of dopamine at neuronal terminals and, as the Authors report, an increase in sexual function [191].
Van Wyk-Grumbach syndrome and trisomy 21
Published in Baylor University Medical Center Proceedings, 2022
Aleida Rivera-Hernández, Mónica Margarita Madrigal-González, Rossana Espinosa-Peniche, Jessie Zurita-Cruz, Lourdes Balcázar-Hernández
Van Wyk-Grumbach syndrome (VWGS) is characterized by severe hypothyroidism, precocious puberty with multiple ovarian cysts with or without breast budding or early menarche, delayed bone age, elevated estradiol, prepubertal luteinizing hormone (LH), elevated follicle-stimulating hormone (FSH), and spontaneous resolution with levothyroxine treatment.1 Nontumor hyperprolactinemia may be present. Down syndrome has been associated with a high susceptibility and prevalence of thyroid disorders, including autoimmune thyroid disease (such as Hashimoto’s thyroiditis), which can lead to severe hypothyroidism.2 Despite the high prevalence of thyroid disorders, the coexistence of VWGS and trisomy 21 is rare. We present a case of a Latino patient with Down syndrome and VWGS.
Related Knowledge Centers
- Galactorrhea
- Hypogonadism
- Infertility
- Lactation
- Menstrual Cycle
- Peptide Hormone
- Pituitary Gland
- Pregnancy
- Prolactin
- Reference Ranges For Blood Tests