24. Hypothalamic and Pituitary Drugs Flashcards
What are the hormones secreted by each of these 3;
The hypothalamus (HT)
Anterior pituitary gland (andenohypophysis)
Posterior pituitary gland
Hypothalamus- CRH, GHRH, GHIH, GnRH, TRH, PIH (DA)
Secreted by arcuate and other HT nuclei and transported to ant pit via hypophyseal portal vessel
Anterior pituitary gland- ACTH, GH, FSH, LH, TSH, PRL
Posterior pituitary gland- OT, AVP/ADH
Slide 3-5
What are all the following hormones for the abbreviations; GHRH GHIH CRH GnRH TRH PIF GH ACTH TSH FSH LH ADH, OT
GHRH- growth hormone releasing hormone from HT, increases GH
GHIH- somatostatin - hypothalamus (HT, GIT) from HT to decrease GH
CRH- corticotropin releasing hormone from HT increases ACTH
GnRH- gonadotropin-releasing hormone from HT increasing FSH/LH
TRH- thyrotropin releasing hormone from HT increases TSH
PIF- dopamine from the HT to decrease prolactin
GH- growth hormone ant pit
ACTH- adrenocorticotropic hormone ant pit
TSH- thyroid stimulating hormone ant pit
FSH- follicle stimulating hormone ant pit
LH- leuteinizing hormone ant pit
ADH, OT- Vasopressin (AVP) & oxytocin post pit
Slide 4-6
What is corticotropin?
ACTH
39 amino acid peptide released from ant pit in response to CRH
ACTH -> adrenal cortex to produce cortisol, aldosterone, and adrenal androgens
Excessive ACTH -> adrenal hyperplasia
ACTH deficiency -> adrenal atrophy
Slide 7
What do cosyntropin and corticorelin do?
Cosyntropin- synthetic form of ACTH used to distinguish congenital adrenal hyperplasia from ovarian hyperandrogenism and also used to diagnose adrenal insufficiency
Corticorelin- recombinant preparation of CRH->ACTH->cortisol, indicated for use in differentiating the excessive cortisol from pituitary or ectopic production of ACTH in patients with Cushing syndrome
Slides 7-8
What is growth hormone?
Directly stims lipolysis and antagonizes insulin time increase blood glucose
Effects mostly mediated by IGFs, aa transport, protein synthesis, and cell proliferation
GH secretion is controlled by GHRH and somatostatin
What are the drugs involved with growth hormone; Somatotropin recombinant Sermorelin Mecasermin Octreotide Pegvisomant
Somatotropin recombinant- treat GH deficiency in children with a low growth rate
Sermorelin- rest whether GH deficiency is secondary to hypothalamic insufficiency or pituitary insufficiency
Mecasermin- recombinant IGF-1 used for IGF-1 deficiency
Octreotide- an 8-aa somatostatin analogue, treatment of acromegaly, carcinoid syndrome
Pegvisomant- pegylated GH receptor antagonist, normalizes serum IGF-1 in persons with acromegaly
Slides 9-11
What is FSH and LH
The ant pit secretes these 2, to pulsation stimulation by GnRH
in females, FSH -> ovarian follicle maturation and LH assists FSH in follicle dev, indices ovulation
In males, FSH -> spermatogensis, LH -> leydigs cell in the testes to produce testosterone
What are the drugs involved with gonadotropins; Menotropins/chorionic gonadotropin Gonadorelin Goserelin/leuprolide/nafarelin Abarelix Ganirelix/cetrorelix
Menotropins/chorionic gonadotropin- for women with infertility and men with hypogonadotropic hypogonadism
Gonadorelin- pulsating admin releases FSH and LH while continuous admin decreases FSH and LH, GnRH agonist
Goserelin, leuprolide, nafarelin- synthetic GnRH continuous admin decreases pituitary GnRH receptors and decreases testosterone
Abarelix- blocks GnRH receptors decreases FSH and LH decreases testosterone
Ganirelix/cetrorelix- used in fertility treatment to prevent premature ovulation, GnRH antagonists
Slides 13-15
What is thyrotropin?
Secreted in response to TRH
Human recombinant TSH is sent to thyroid gland to take up radioactive iodine for various thyroid conditions and for follow up evaluations of thyroid cancer patients
Protirelin- used for diagnosis of central hypothyroidism
Slide 16
What is prolactin?
Released from ant pit and sent to mammary gland tissue growth and lactation (milk prod) in the presence estrogen, progestins and other
PRL secretion is inhibited by PIH and is stimulated by HT PRL-releasing factors
Normally humans have low plasma PRL level
During lactation there is less PIF resulting in increased PRL level to maintain lactation
Hyperprolactinemia (PRL excess) causes galactorrhea (excessive milk prod), hypogonadism, and infertility
What are the drugs involved with prolactin;
Cabergoline
Bromocriptine
Both used to treat hyperprolactinemia
Bromocriptine is also used for Parkinson’s
Cabergoline selectively activates D2 receptors in Pit and suppresses PRL secretion
Slide 18
What is oxytocin and vasopressin?
OT and AVP are 9 amino acid peptides released from posterior pit. In response to specific physiologic stim
OT controls strength of uterine contraction and milk ejection by contracting myoepithelial cells of ducts of the breast
Vasopressin is an anti diuretic and vasopressor hormone stored in post pit and released in response to plasma osmotic pressure
Vasopressin increases cAMP, increases insertion of water channels in collecting duct
Slides 19-23
What is synthetic oxytocin used for?
To induce or enhance uterus contraction during labour at term to prevent postpartum uterus hemorrhage
Slide 20
What does desmopressin do?
What does injectable vasopressin do?
Desmopressin- long acting synthetic AVP/ADH analog, to treat neurogenic diabetes insipidus, and increased water intake to prevent nocturnal urine production and enuresis
Slide 22
Injectable vasopressin- used to control bleeding caused by esophageal varices or colonic diverticula
Slide 23
