Flashcards in Hypothalamic and Pituitary Hormones 2.1 Deck (16):
MOA of ACTH analogs
Stimulate adrenal cortex via MC2 receptor -> increased cAMP -> steroid hormone secretion.
Clinical application of ACTH analogs (2)
1) Differentiate between primary and secondary adrenal insufficiency
2) Infantile spasm (West Syndrome) treatment
Acts on GPCRs -> stimulates release of prostaglandins & leukotrienes that augment uterine contraction.
Small doses of Oxytocin does what?
Increases force and frequency of contractions
Higher doses of Oxytocin does what?
evokes sustained contractions. Weak antidiuretic & pressor activity (vasopressin R activation).
How does Oxytocin cause milk ejection?
Contraction of myoepithelial cells surrounding mammary alveoli.
Oxytocin IV is used when
Initiation and augmentation of labor
Oxytocin IM is used when
control of postpartum bleeding
Adverse effects of Oxytocin (3)
1) Excessive stimulation of uterine contraction: fetal distress, placental abruption, uterine rupture
2) Inadvertent activation of vasopressin receptors: excessive fluid retention, water intoxication -> hyponatremia, heart failure, seizures, death.
3) Bolus injections can lead to hypotension
Oxytocin contraindications (5)
• Fetal distress
• Abnormal fetal presentation
• Cephalopelvic disproportion
• Uterine rupture predisposition
Released in response to rising plasma tonicity or falling BP
Long acting synthetic analog of vasopressin with minimal V1 activity
V1R activation (via vasopressin agonists) leads to?
Vascular smooth muscle -> vasocontriction