Pharmacological actions

PHARMACOLOGICAL ACTIONS

  • Pharmacological actions of catecholamines can be studied under four major categories.
    • Excitatory
      • Blood vessels - constriction (including veins, increased venous return to heart).
      • Iris - contraction of the radial muscle with mydriasis .
      • GI & Urinary - contraction of the sphincters.
      • Sweat glands - secretion in horse.
      • Salivary glands - viscous secretion .
      • Male genetalia - ejaculation .
    • Inhibitory
      • Bronchioles - dilatation.
      • Blood vessels - dilatation.
      • GI Tract - relaxation of smooth muscle .
      • Urinary bladder - relaxation of detrusor .
    • Cardioexcitatory effects
      •  SA node - increased heart rate
      •  Atria & Ventricles - increased force of contraction, conduction velocity.
      • AV node & His Purkinje System - increased automaticity, conduction velocity.
    • Metabolic effects
      • Liver - glycogenolysis and gluconeogenesis, hyperglycemia.
      • Pancreas decrease (α) and increased (β) secretion.
      • Fat cells - lipolysis, increased plasma free fatty acids .
      • Skeletal - Muscle glycogenolysis, increased blood lactate .
  • In addition to these effects, some CNS effects are also noticed.
Last modified: Tuesday, 15 May 2012, 6:10 AM