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46 Cards in this Set
- Front
- Back
What are three uses for agents that affect endocrine function? |
1) to analyse the functional integrity of endocrine control systems-->diagnostic tests-->ex: somatotrophin test for GH responsiveness 2) as replacements in hormone deficiency states-->ex: thyroid hormone for hypothyroidism 3) to modify endocrine system function-->ex: dopamine agonists for hyperprolactinaemia, oral contraception |
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How do agents influence endocrine systems? |
1) mimic or block the actions of endogenous hormones-->agonists in the absence of endogenous hormones, antagonists in the presence of excess endogenous hormones 2) interfere with regulation pathways-->increase/decrease endogenous hormone levels |
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Which hormones are made/released by the hypothalamus? (9) |
1) dopamine 2) VIP 3) TRH 4) somatostatin 5) GRH dopamine 6) GnRH 7) CRH 8) vasopressin 9) oxytocin |
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What hormones are released by the anterior pituitary? (6) |
1) PRL 2) TSH 3) GH 4) FSH 5) LH 6) ACTH |
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Which hormones are stored and released by the posterior pituitary? (2) |
1) vasopressin 2) oxytocin |
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What are the 3 vasopressin receptors and what do they do in the end? |
V1A-->vasoconstriction V1B--> ACTH release V2-->water reabsorption in DCT and CT |
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What is the oxytocin receptor and how does it work in the end? |
OT-->inhibits AC |
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What are the actions of oxytocin? |
contracts the smooth muscle of the uterus causes milk release during lactation positive social interactions enhances social contract and promotes social cohesion |
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What are the actions of vasopressin/ADH and when is it released? |
control of body water
released in response to change in blood osmolality |
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What is diabetes insipidus? |
vasopressin (ADH) deficiency |
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What are the symptoms of diabetes insipidus? |
thirst polydipsia polyuria |
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What is pituitary diabetes insipidus due to? |
due to decreased vasopressin |
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What is neurogenic diabetes insipidus due to? |
due to decreased vasopressin |
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What is nephrogenic diabetes insipidus? |
due to decreased response to vasopressin |
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How is pituitary diabetes insipidus treated? |
with vasopressin or analogues vasopressin desmopressin |
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What is desmopressin selective for? What is it a potential use for it? |
V2 receptors nocturnal enuresis |
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What is vasopressin (ADH) excess caused by and how is it treated? |
due to small cell carcinoma in the lung-->ectopic vasopressin secretion hypertension and fluid retention treat with V-receptor antagonists |
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What are V2 agonists associated with? |
increased water reabsorption |
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What are V1A receptor agonists associated with? |
vasoconstriction |
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What are V1A and V1B receptor agonists associated with? |
behavioural and endocrine responses to stress and anxiety |
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What are prolactin receptors linked to? (enzyme) |
tyrosine kinase-linked |
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What hormones can enhance prolactin release? |
TRH VIP-->Vasoactive intestinal peptide oxytocin |
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What hormone does prolactin suppress? |
supresses estrogen synthesis decreased GnRH |
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What causes prolactin hyper secretion? |
DA antagonists-->classic antipsychotic agents hypothyroidism-->due to increased TRH pituitary tumors-->lactotrophic cells |
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What symptoms does prolactin hyper secretion cause? |
infertility galactorrhea |
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How is prolactin excess treated? |
dopamin receptor agonists-->can shrink pituitary lactotroph adenomas |
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ADRs of dopamine receptor agoinsts |
nausea & vomiting dizziness, postural hypotension tolerance develops to side-effects but not to the therapeutic effect |
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What are growth hormone (somatotrophin) receptors linked to? |
tyrosine kinase |
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How does somatotrophin (GH) work? |
increases IGF-1 (somatomedin) to mediate anabolic effects |
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What stimulates GH release? |
GHRH (somatorelin) |
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What inhibits GH release? |
GHIH (somatostatin) |
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What other factors causes growth hormone (somatotrophin) release? |
exercise stress hypoglycemia |
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What are some possible causes of growth hormone deficiency? |
hypopituitarism selective impairments of somatotrophs deficient GHRH release |
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What are the consequences of growth hormone (somatotrophin) deficiencies in children and adults? |
children--short stature adults-->wasting--> increased body fat, decreased muscle mass, decreased BMD |
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What are the treatments for growth hormone (somatotrophin) deficiency? |
pituitary extracts recombinant human GH (rhGH) somatropin (synthetic hGH) |
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What are the effects of somatropin (hGH)? |
growth promoting effects-->promotes growth of skeletal, muscular and other tissues anabolic effects-->stimulates protein anabolism and influences fat and mineral metabolism |
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ADRs of somatropin |
muscle pain joint pain MS stiffness local reactions, lipoatrophy peripheral edema hypothyroidism |
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What are GH releasing factors used for? |
analogues diagnostic test for GH release potentially anti-ageing therapy HIV-related lipodystrophy |
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What is the common cause of growth hormone excess? |
adenoma |
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What does excess GH cause in children and adults? |
children-->giantism adults-->acromegaly |
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What is the treatment of acromegaly? |
aim is to normalise GH and IGF levels surgery usually 1st option-->removal or debulking Drugs-->DA receptor agonists, somatostatin analogues, GH receptor antagonist |
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What are some pros and cons to DA receptor agonists in the treatment of acromegaly? |
cheapest option only 20% of patients respond normalises GH secretion in these patients ADR profile is problematic |
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What are some pros and cons to somatostatin analogues? |
longer actiing supresison test may be used to see if respond can cause hypothyroidism |
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ADRs somatostatin analogues |
injection site reactions headache dizziness GI upset hypothyroidsism due to low TSH |
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What do GH receptor antagonists do? |
do not decrease gH levels or tumour size stops GH effects on target tissues |
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ADRS GH receptor antagonist |
injection site reactions swollen limbs chest pain hypoglycaemia |