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18 Cards in this Set
- Front
- Back
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little PRL
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MW=23 kd.
high bioactivity and immunoreactivity |
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glycosylated PRL
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MW=25 kd.
less bioactivity and immunoreactivity than Little PRL |
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Big PRL
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MW=50 kd.
-combo of di- and trimeric G-PRL. decreased receptor binding |
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Big-big PRL
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MW=100 kd.
-G-PRL coupled w/IgG |
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rel'n b/w hyperprolactinemia and galactorrhea
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-Galactorrhea can be present without hyperprolactinemia.\
-immunoreactivity (assay) vs. bioactivity -60% pts w/galactorrhea have hyper-PRL |
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waht stimulates/inhibits PRL secretion
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Stimulates PRL:
-serotonin -TRH -VIP -ATII -Opioids Inhibit PRL: -DA (pit stalk interruption==>PRL release d/t loss of DA) -GABA |
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effects of Pregnancy on PRL
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-PRL rises soon after implantation (PRL rises w/estrogen), but no milk secreted b/c progesterone inhbiits expression of PRL receptors in breast
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effects of nursing on PRL
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-suckling==>incr PRL==>produces milk for subsequent feeding
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what does oxytocin do
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causes milk let-down
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hourly variation of PRL: EXAM
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-highest PRL during nocturnal sleep (3 am)
-lowest PRL in morning (9-11am) -PRL incr with protein at lunch time -best times to measure PRL: -morning -fasting |
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conditions assoc w/incr PRL release
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1. preg
2. nursing 3. sleep 4. food 5. stress 6. orgasm 7. breast stimulation (eg breast exam) |
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Inappropriate PRL secretion
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A. Central causes
1. Hypothalamic -hypo stalk resection 2. Pit a. Adenoma (secrete PRL) -microadenoma (<=10mm) -macroadenoma (>10mm) B. Peripheral causes 1. Hypothyroidism (incr TRH) 2. Chest Wall Reflex 3. Renal failure==>decr renal Clearance of PRL 4. Ectopic: a.bronchogenic carcioma b.hypernephroma C. Drugs 1. Anesthesia 2. Psychoactive agents: a.neuroleptics (DA antagonist) b.TCA (incr precursors) c. diazepam d. antihyerptensives |
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consequences of hyperprolactinemia
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A. Galactorrhea
B. Mastalgia (breast pain) C. Menstrual Abnl 1. Hypoestronism 2. bone loss (incr PRL==>incr DA (positive feedback)==>decr GnRH pulsatility ==>anovulatory or amenorrhea D. Hyper-androgenism E. Insulin resistance |
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galactorrhea workup
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-check fasting AM prolactin level
-PE: microscopic- fat droplets |
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Tx Hyper-PRL
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bromocriptine or cabergoline (DA analogs)
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Microadenomas: Management
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MICROADENOMAS (<= 10mm)
A. Expectant management *if follows a benign course, microadenoma growth is slow *no Tx req unless: -want to get pregnant, -hypoestrogenemia exists, -galactorrhea is bothersome B. **Management is based on menses 1. Regular menses==>Expectant a.yearly PRL levels 2. Oligomenorrheic a.cyclic progestin b. OCP's 3. Hypoestrogenic a. Estrogen Replacement b. OCP's C. Medical management (with bromocriptine) -90% euprolactinemic (nl PRL levels) -decr adenoma size -80% fertility -60% stop galactorrhea -After discontinuing bromocriptine: -following 1 yr Tx: 10-20% remain euprolactinemic after d/c bromocriptine -following 2 yr Tx: 22% euprolactinemic |
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Macroadenoma: Management
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-Thyroid function tests
-Adrenal function: do insulin tolerance test -DOC= Bromocriptine for 6 months -Surgery (transphenoidal or transfrontal) not great b/c high rate of recurrence |
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how Tx women with PRL-secreting tumors
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bromocriptine (it's safe, no effect on placental fxn
also, it's safe to breastfeed) |
