Adenosine 5'-triphosphate (ATP) receptors induce intracellular calcium changes in mouse leydig cells
Por:
Pérez-Armendariz E.M., Nadal A., Fuentes E., Spray D.C.
Publicada:
1 ene 1996
Resumen:
Cytoplasmic calcium ([Ca 2+] i) changes evoked by adenosine 5 1-triphosphate (ATP) were recorded in cultured individual Leydig cells within 10-18 h after cell dispersion. [Ca 2+] i was monitored using Fura-2AM loaded cells with a digital ratio imaging system. Five micromolars ATP induced biphasic [Ca 2+] i responses in most cells (94%, n=100), characterized by a fast increase from a basal level (126±5 n MSE, n=60 cells) to a peak (5-7 times above basal levels) within seconds, followed by a slow decrease toward a plateau level (2-3 times above basal) within 5 min. The peak phase of the [Ca 2+] i response increased with ATP concentrations (1-100 ?M ATP) in a dose-dependent manner with an IC 50 of 5.9±1.2 ?M, and it desensitized in a reversible manner with repeated application of 5 ?M ATP at <5-min intervals. The [Ca 2+] i peak response was dependent on Ca 2+ release from an intracellular pool, whereas the plateau phase was dependent on extracellular [Ca 2+]. ATP did not appear to induce formation of nonspecific membrane pores, since stimulation for 10 min with ATP (10-100 ?M) in the presence of extracellular Lucifer yellow (LY) (5 mg/mL) did not result in dye loading of the cells. [Ca 2+] i transients were elicited by other adenosine nucleotides with an order of potencies (ATP>Adenosine diphosphate [ADP]>Adenosine> Adenosine monophosphate [AMP]) that was compatible with the expression of P 2 receptors. [Ca 2+] i responses were suppressed by the purinergic P 2 receptor antagonist, suramin. These results provide functional evidence for the expression of purinergic P 2 receptors in Leydig cells. © 1996 Human Press Inc.
Filiaciones:
Pérez-Armendariz E.M.:
Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States
Departamento de Fisiología, Biofísica y Neurociencias, Centro de Investigación y Estudios Avanzados, I.P.N., México, Mexico
c/o M. Romano, Dept. Fisiología, Biofísica y Neurociencias, CTNVESTAV, I.P.N., Ap. Postal 14-740, México, D. F., 07000, Mexico
Nadal A.:
Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States
Fuentes E.:
Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States
Spray D.C.:
Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, United States
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