Effects of trachynilysin, a protein isolated from stonefish (Synanceia trachynis) venom, on frog atrial heart muscle

Autor: Martin-Pierre Sauviat, Arnold S. Kreger, Frederic A. Meunier, Jordi Molgó
Přispěvatelé: Laboratoire d'optique appliquée (LOA), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de neurobiologie cellulaire et moléculaire (NBCM), Centre National de la Recherche Scientifique (CNRS), Institut de Neurobiologie Alfred Fessard (INAF), Department of Medicine and Department of Dermatology, University of Maryland School of Medicine, University of Maryland System-University of Maryland System
Rok vydání: 2000
Předmět:
Atropine
Contraction (grammar)
MESH: Myocardial Contraction
MESH: Drug Interactions
Action Potentials
Toxicology
Trachynilysin
Fish Venoms
Muscarinic acetylcholine receptor
Drug Interactions
MESH: Animals
MESH: Action Potentials
Membrane potential
0303 health sciences
Contraction
030302 biochemistry & molecular biology
Fishes
Rana esculenta
MESH: Electric Stimulation
MESH: Fish Venoms
MESH: Rana esculenta
MESH: Calcium
Intracellular Ca2+
cardiovascular system
GRENOUILLE
[SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]
medicine.symptom
Acetylcholine
medicine.drug
Muscle contraction
medicine.medical_specialty
Neurotoxins
Biology
MESH: Atropine
03 medical and health sciences
Internal medicine
medicine
Animals
Heart Atria
MESH: Neurotoxins
030304 developmental biology
MESH: Acetylcholine
Action potential
Myocardial Contraction
Electric Stimulation
MESH: Fishes
Endocrinology
Heart muscle
Cholinergic
Calcium
MESH: Heart Atria
Zdroj: Toxicon
Toxicon, Elsevier, 2000, 38 (7), pp.945-59. ⟨10.1016/S0041-0101(99)00207-X⟩
ISSN: 0041-0101
DOI: 10.1016/s0041-0101(99)00207-x
Popis: The effects of trachynilysin (TLY), a protein toxin isolated from stonefish (Synanceia trachynis) venom, were studied on the electrical and mechanical activities of frog atrial fibres. TLY (1 microg/ml) hyperpolarized the membrane, shortened the action potential (AP) duration (APD), exerted a negative inotropic effect and elicited contracture. These effects did not develop in the presence of atropine. TLY shortened the APD of fibres isolated from a frog completely paralyzed with botulinum type A toxin, in the presence of Ca2+ but not when Ca2+ was replaced by Sr2+. TLY increased the basal and the peak of the fluorescence ratio of stimulated fibres loaded with fura-2. Confocal laser scanning microscopy revealed the existence of a diffuse innervation in atrial tissue. Our results suggest that TLY enhances the release of acetylcholine from atrial cholinergic nerve terminals and activates indirectly muscarinic receptors leading to a shortening of APD. They also show that the mechanical effects induced by TLY are due to an increase of the Ca2+ influx and to a rise in intracellular Ca2+ levels which leads to (i) a slowing of the Na+/Ca2+ exchange activity, which accounts for the contracture and (ii) the activation of a Ca2+-dependent K+ current involved in the APD shortening.
Databáze: OpenAIRE
Externí odkaz: