Alpha-adrenoceptor

subtype was historically misclassified and is now recognized as α1Aalpha sub 1 cap A end-sub α2alpha sub 2

: Increased intracellular calcium leads to smooth muscle contraction (e.g., vasoconstriction). α2alpha sub 2 Mechanism: The Gicap G sub i α2alpha sub 2 -receptors are coupled to proteins , which inhibit Adenylyl Cyclase . cAMP Reduction : Lowers intracellular cyclic AMP levels. Ion Channel Modulation : Opens K+cap K raised to the positive power channels or inhibits Ca2+cap C a raised to the 2 plus power alpha-adrenoceptor

Hypertension, Benign Prostatic Hyperplasia (BPH) , nasal congestion α2alpha sub 2 CNS (brainstem), presynaptic terminals Decreased sympathetic outflow, sedation, analgesia Hypertension, sedation (Dexmedetomidine), ADHD 💡 : α1alpha sub 1 activation is generally stimulatory (constriction), while α2alpha sub 2 subtype was historically misclassified and is now recognized

: They play a role in regulating glucose uptake and fatty acid oxidation. Ion Channel Modulation : Opens K+cap K raised

are a class of G-protein coupled receptors (GPCRs) that mediate the actions of catecholamines like norepinephrine and epinephrine in the sympathetic nervous system. They are broadly divided into two families, α1alpha sub 1 α2alpha sub 2

Alpha receptors utilize different G-protein families to trigger intracellular responses. α1alpha sub 1 Mechanism: The Gqcap G sub q α1alpha sub 1 -receptors are predominantly linked to the protein , which activates Phospholipase C (PLC) . IP3 Generation : Triggers the release of Ca2+cap C a raised to the 2 plus power from the sarcoplasmic reticulum. DAG Generation : Activates Protein Kinase C (PKC) .