- Physiology
- Synthesis: Synthesized in the Hypothalamus (specifically the Supraoptic and Paraventricular nuclei).
- Storage/Secretion: Transported to and secreted by the Posterior Pituitary (Neurohypophysis).
- Mechanism of Action:
- V1 Receptors: Located on vascular smooth muscle → Gq pathway → Vasoconstriction (↑ BP).
- V2 Receptors: Located on principal cells of the renal collecting duct → Gs pathway → Insertion of Aquaporin-2 channels into the apical membrane → ↑ Water Reabsorption.