Effect of propionyl-L-carnitine on L-type calcium channels in human heart sarcolemma

Journal Article · Fri Feb 01 00:00:00 EST 1991 · Cardiovascular Drugs and Therapy; (USA)

DOI:https://doi.org/10.1007/BF00128241· OSTI ID:5545200

Bevilacqua, M; Vago, T; Norbiato, G ^[1]

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1. Servizio di Endocrinologia, Milano, (Italy)

Propionyl-L-carnitine (PC) protects perfused rat hearts against damage by ischemia-reperfusion. Activation of L-type calcium channel play a role on ischemia-reperfusion damage. Therefore, we studied the effect of PC on some properties of L-type calcium channels in an in vitro preparation from human myocardium sarcolemma (from patients with idiopathic dilated cardiomyopathy). Binding of the L-type calcium channel blockers isradipine ({sup 3}H)-PN 200-110 (PN) to plasma membrane preparations revealed a single population of binding sites (total number: Bmax = 213 +/- 34 fM/mg protein and affinity: Kd = 152 +/- 19 nM; n = 6). The characteristics of these binding sites were evaluated in the presence and in the absence of Ca{sup 2}{sup +} and of calcium blockers (D-888, a verapamillike drug, and diltiazem). Incubation in a Ca{sup 2}{sup +}-containing buffer increased the affinity of PN binding sites. Binding sites for PN were modulated by organic calcium channel blockers; in competition isotherms at 37{degree}C, D-888 (desmethoxyverapamil) decreased the PN binding, whereas diltiazem increased it. These results strongly suggest that the site labelled by PN is the voltage-operated calcium channel of the human myocardium. The addition of PC (1 mM) to plasma membranes labelled with PN at 37{degree}C decreased the affinity of the binding; this effect was counteracted by the addition of Ca{sup 2}{sup +} to the medium. This result was consistent with a competition between Ca{sup 2}{sup +} and PC. The effect of PC incubation at 4{degree}C was the opposite; at this temperature PC increased the affinity of the binding sites and the effect was obscured by Ca{sup 2}{sup +}.

• OSTI ID: 5545200
• Journal Information: Cardiovascular Drugs and Therapy; (USA), Vol. 5 Suppl 1; ISSN 0920-3206
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CARNITINE
BIOLOGICAL FUNCTIONS
ISCHEMIA
PATHOGENESIS
PORINS
BIOCHEMICAL REACTION KINETICS
AFFINITY
CALCIUM
CELL MEMBRANES
HEART
IN VITRO
MAN
MYOCARDIUM
OXADIAZOLES
PERFUSED ORGANS
RECEPTORS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ALKALINE EARTH METALS
AMINO ACIDS
ANEMIAS
ANIMALS
AZOLES
BODY
CARBOXYLIC ACIDS
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
CELL CONSTITUENTS
DISEASES
ELEMENTS
HEMIC DISEASES
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
HYDROXY ACIDS
ISOTOPE APPLICATIONS
KINETICS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
METALS
MUSCLES
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
ORGANS
PRIMATES
PROTEINS
REACTION KINETICS
SYMPTOMS
VASCULAR DISEASES
VERTEBRATES
VITAMIN B GROUP
VITAMINS
550901* - Pathology- Tracer Techniques