G-protein linked 2nd messengers, Pharma gen Flashcards
What is supplied by sympathetic innervation?
Cardiac muscles, smooth muscles (vasculature) Nerve terminals (NE outflow) Gland cells (insulin) Sweat glands (M receptors) Adrenal medulla (N receptors)
What is supplied by parasympathetic innervation?
Largely glands (lacrimal, salivary, endocrine/GI glands)
Cardiac muscle, smooth muscles
Nerve terminals
alpha1 receptors
Sympathetic, Gq
Vasoconstriction
Pupillary dilator muscle (contraction, mydriasis)
Intestinal/bladder sphincters (contraction)
Dec. renin
alpha2 receptors
Sympathetic, Gi Dec. sympathetic outflow (dec. NE) Dec. insulin, Dec. lipolysis Dec. aqueous humor prodn Inc. platelet aggregation (stress, Epi)
Beta1 receptors
Sympathetic, Gs; Cardiac muscle
SA/AV nodes (inc. HR)
Inc. contractility
Inc. renin
Beta2 receptors
Sympathetic, Gs; Not innervated Vasodilation, Bronchodilation Inc. lipolysis, Inc. insulin (gluconeogenesis) Inc. aqueous humor prodn Dec. uterine tone (tocolysis)
M1 receptors
Parasympathetic, Gq
GIT gland secretion (enteric)
CNS
M2 receptors
Parasympathetic, Gi; Heart
SA/AV (dec. HR)
Dec. atrial contractility (ventricles affected via Purkinje system)
M3 receptors
Parasympathetic, Gq
Inc. exocrine secretions (lacrimal, salivary, gastric acid)
Bladder contraction, Gut peristalsis, Bronchoconstriction
Pupillary sphincter contraction (miosis); ciliary muscle contraction (accommodation)
Vasodilation (via NO, not innervated)
D1 receptors (peripheral)
Gs
Renal vasodilation – inc. renal blood flow, inc. GFR, inc. Na secretion
Also in mesenteric, coronary vasculature
*Central D1: Basal ganglia, direct pathway
D2 receptors
Gi
Modulates transmitter release (brain) – movement
H1 receptors
Gq; Asthma, allergy
Inc. mucus production (nasal, bronchial)
Inc. vascular permeability
Bronchiolar contraction, pruritus, pain
H2 receptors
Gs
Inc. gastric acid secretion
V1 receptors
Vasopressin, Gq
Inc. vasoconstriction
V2 receptors
Vasopressin, Gs
Inc. H2O permeability and reabsorption in collecting tubules
