Term
| Six Major Pituitary Hormones |
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Definition
| ACTH, GH, PRL, TSH, LH, FSH |
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Term
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Definition
| PRL consists 198 amino acids molecular mass of 21,500 kDa; similar to GH and hPL. synthesized by lactotropes |
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Term
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Definition
| produce PRL and compromise 20% or anterior pituitary cells. same common precursor as somatotropes which give rise to tumor secreting both PRL and GH. Hyperplasia during lasat two trimesters of pregnancy and few months of lacatation |
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Term
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Definition
| synthesis begins at 12 weeks gestation. normal adult levels are 10 to 25 ug/L in women and 10-20 ug/L in men. pulsatile with highest during REM. Peak between 4-6 a.m. circulating half-life 50min. inhibited by dopamine. glucocorticoid and thyroid hormone suppress PRL secretion. Serum levels rise after cexercise, meals, sex, stress, minor surgical procedures. |
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Term
| Inhibitors/Suppressors of Prolactin |
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Definition
| Dopamine inhibits secretion. Glucocorticoids and thyroid hormones suppress PRL secretion. |
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Term
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Definition
| dopamine agonists (levodopa). Pituitary destruction or removal and lymphocytic hypophysitis. |
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Term
| Type 1 cytokine receptor family |
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Definition
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Term
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Definition
| ligand binding leads to receptor dimerization followed by intracellular signaling mediated by JAKII. In breast lactogens, elevated progesterone. PRL induces and maintains lactaion, decreases reproductive function, suppress sexual drive. suppresses hypthalamic GnRH and pituitary gonadotropin secretion in ovary. PRL blocks folliculogenesis leading to hypoestrogenism and anovulation. inhibits spermatogenesis. decrease libido, reduce fertility with heperprolactinemia. brain centers for parenting behavior, appetite stimulation |
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Term
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Definition
| associated with enhanced risk for bone loss and long-term development of osteoporosis. |
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Term
| Etiology Hyperprolactinemia |
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Definition
| HPRL most common pituitary hormone hypersecretion syndrome in both males and females. PRL-secreting pituitary adenomas are most common cause of PRL levels>100ug/L. Hypothalamic/Pituitary stalk compression or lesions. chest wall trauma. pituitary tumors. |
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Term
| Treatment of Hyperprolactinemia |
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Definition
| depends on cause of elevated PRL levels. dopamine agonists are effective for many different causes of hyperprolactinemia. |
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Term
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Definition
| tumors of lactotrope cells, mixed tumors secreting combinations. tumor size correlates directly with PRL concentrations; 100ug/L associated with macroadenomas |
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Term
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Definition
| less than 1 cm in diameter |
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Term
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Definition
| greater than 1 cm diameter. generally associated with levels 100ug/L |
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Term
| Female:Male ratio microprolactinomas |
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Definition
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Term
| Female:Male Macroprolactinomas |
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Definition
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Term
| Woman Clinical Signs and Symptoms of Prolactinoma |
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Definition
| woman usually present with amenorrhea. Infertility. Galactorrhea, if tumor extends outside of the sella, visual field defects. |
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Term
| Man Clinical Signs and Symptoms of Prolactinoma |
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Definition
| impotence, loss of libido, infertility, or signs of CNS compression including headaches and visual defects. diagnosis is PRL > 100ug/L. PRL levels <100ug/L may be caused by microadenomas, other sellar lesions that decrease dopamine inhibition, or nonneoplastic causes of hyperprolactinemia. |
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