ITRIN 5 MG 14 TAB

INDICATION FOR THE TREATMENT OF SYMPTOMATIC BPH AND MILD TO MODERATE HYPERTENSION. MECHANISM OF ACTION IN GENERAL A1-ADRENERGIC RECEPTORS MEDIATE CONTRACTION AND HYPERTROPHIC GROWTH OF SMOOTH MUSCLE CELLS. A1-RECEPTORS ARE 7-TRANSMEMBRANE DOMAIN RECEPTORS COUPLED TO G PROTEINS GQ/11. THREE A1-RECEPTOR SUBTYPES WHICH SHARE APPROXIMATELY 75% HOMOLOGY IN THEIR TRANSMEMBRANE DOMAINS HAVE BEEN IDENTIFIED: A1A (CHROMOSOME 8) A1B (CHROMOSOME 5) AND A1D (CHROMOSOME 20). TERAZOSIN IS THE FIRST A1-RECEPTOR ANTAGONIST TO DEMONSTRATE SELECTIVITY FOR THE A1A-RECEPTOR. ALL THREE RECEPTOR SUBTYPES APPEAR TO BE INVOLVED IN MAINTAINING VASCULAR TONE. THE A1A-RECEPTOR MAINTAINS BASAL VASCULAR TONE WHILE THE A1B-RECEPTOR MEDIATES THE VASOCONTRICTORY EFFECTS OF EXOGENOUS A1-AGONISTS. ACTIVATION OF A1-RECEPTORS ACTIVATES GQ-PROTEINS WHICH RESULTS IN INTRACELLULAR STIMULATION OF PHOSPHOLIPASES C A2 AND