Electrical activity alterations induced by chronic absorption of lindane (gamma-hexachlorocyclohexane) trace concentrations in adult rat heart.
The heart of adult rat offspring, born to mothers treated with trace concentrations of lindane (0.5 to 2 ppb) through a beverage and to mothers chronically treated with lindane (CL-T) with the same trace concentration, also through a beverage, during lactation and growth has a round shape and accumulates lindane. The left ventricle (LV) presents a hypertrophied area, atrophied papillary muscles, and unorganized collagen bundles and layers. These observations led us to study the electrical activity of their left ventricle papillary muscles (LVPM) by recording action potential using intracellular microelectrodes. CL-T shortened LVPM action potential duration (APD): 1 ppb shortened the plateau; 2 ppb shortened the plateau and the slow repolarizing phase. In CL-T (2 ppb) and untreated groups, low temperature (22 degrees C) decreased the resting potential and prolonged APD. TEA (tetraethylammonium; 1-2 mmol/L) partially lengthened CL-T (2 ppb lindane) APD. Quinidine (0.2 mmol/L) and E-4031 (10 nmol/L) prolonged CL-T APD, suggesting that the rapid delayed outward K+ current (IKr) was increased. Our results indicate the silent effects of chronic exposure to trace concentrations of lindane on the morphological and electrical activity of heart muscle. They demonstrate that chronic lindane treatment of female rats alters the tissue integrity and electrical activity in the LV of their offspring.
Sauviat
Martin-Pierre
MP
Institut National de la Santé et de la Recherche Médicale Unité 696-Centre National de la Recherche Scientifique Unité Mixte de Recherche 7654-Ecole Polytechnique, Palaiseau, France. martin-pierre.sauviat@polytechnique.fr
Bouvet
Suzanne
S
Godeau
Gaston
G
Pages
Nicole
N
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D003080:Cold Temperature; D004305:Dose-Response Relationship, Drug; D005260:Female; D001556:Hexachlorocyclohexane / Q000008:administration & dosage / Q000032:analysis / Q000494:pharmacology*; D008297:Male; D009206:Myocardium / Q000473:pathology*; D010210:Papillary Muscles / Q000187:drug effects* / Q000502:physiology; D026902:Potassium Channel Blockers; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D051381:Rats; D019789:Tetraethylammonium
D026902:Potassium Channel Blockers; D001556:Hexachlorocyclohexane; D019789:Tetraethylammonium