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What are possible solutions/treatments for hypersecretion of an endocrine gland?
- Removal of tissue by surgery, irradiation followed with replacement therapy
- Administration of drugs./hormones that suppress synthesis and secretion of the hormone
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What are the 3 chemical classes of hormones?
- Steroids: adrenal, sex, claciferols, vitamins
- Peptides/proteins: hypothalamic releasing factors, pituitary hormoines, insulin/glucagon/calcitonin/oxytocin/vasopressin/relaxin/GI hormones
- Amines: dopamine, epi, thyroid hormones
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What is the administration route for the differet types of hormones?
- Parenterally: peptide and catecholamens
- Oral: synthetic steroids and thyroid hormones
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What is the system of simple negative feedback control?
- Hormone secreted from endocrine gland
- Hormone travels to target cell via blood
- Substrate released
- Increased level of substrate in blood inhibits release of hormone from endocrine gland
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What are examples of simple negative feeback control?
- glucagon/glucose
- PTH/plasma clacium
- aldosterione/plasma sodium
- insulin/glucose
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What are examples of complex endocrine control system?
- TRH/TSH/thyroxine
- CRH/ACTH/glucocorticoids
- GnRH/LH & FH/estrogen & progesterone
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What are the effects of GH on normal tissue?
- Positive nitrogen balance
- Protein synthesis enhanced
- Electrolyte retention
- AA transport into tissues
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What are the effects of GH in DM?
Hyperglycemia and ketosis
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What is Somatomedin C?
- Insulin-like Growth Factor 1
- Stimulated by GH to stimulate chondrocytes to form cartilage and matrix
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How is GH release regulated?
GHRH (positive effect) or somatostatin/SST (negative effect) released from neurons in hypothalamus
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What is the signal pathway of GHRH in the pituitary?
- Receptor
- Gs (stimulatory) transducer
- Increase Adenylyl Cyclase
- Increase cAMP
- Activate protein kinase A
- Phosphorylation of proteins
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What is the signal pathway of SST in the pituitary?
- Receptor
- 1. Gi (inhibitory) transducer
- Decrease Adenylyl Cyclase
- Inhibit GH relase
- 2. Go (inhibitory) transducer
- Inhibit Ca2+ channels
- Inhibit GH release
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What are factors the stimulate GH release?
- Hypoglycemai
- Oral/IV AAs
- Deep sleep
- Exercise
- Dopamine Agonists
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What is Sermorelin?
Synthetic GHRH for treatment of hypopituitary dwarfism from GHRH deficiency at hypothalamic level
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What is Mecasermin?
- Synthetic IGF-1 protein that binds to and increases t1/2 of human IGF-1
- Used in Laron Syndrome with defective GH receptors
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What is the treatment of Hypopituitary Dwarfism?
- GH SQ/IM thoughout childhood
- Dex hormones at puberty
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What's the effect of glucocorticoids on GH?
Decrease GH release
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What's the treatment of Hyperpituitary Dwarfism?
- Defective GH receptros can't stimulate IGF-1
- Mescasermin therapy increases IGF-1 t1/2
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What's the risk brough by use of GH for cosmetic purposes?
Carpal Tunnel Syndrome
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What's bromocriptine?
- Dopamine agonist
- Paradoxocal inhibition of GH release in pts with Acromegally
- Best in pts with GH & Prolacitn adenoma
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What's Octreotide?
- SST synthetic analog with longer t1/2
- IM once a month for Acromegally
- SE: nausea, diarrhea, abdominal pain
- Pancreatic cholera (inhibits VIP secretion)
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What's Pegvisomant?
- GH antagonist
- Binds to GH receptors to decrease IGF-1 production
- SQ daily
- SE: site reactions, nausea, diarrhea, chaest pain, flu syndrome
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What regulates Prolactin release?
- Dopamine from hypothalamus (Inhibits synthesis and release)
- TRH (enhncaese prolactin release via Ca2+ mobilization)
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What factors stimulate prolactin secretion?
Preganancy (sucking, stress, hypoglycemia, estrogen)
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What's the treatment for hyperprolactinemia?
- Bromocriptine (dopamine agonist)
- S/S: galactorreha, amenorrhea, vision impairment
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