title: Effect of ion composition on the changes in membrane potential induced with several stimuli in rat mast cells.
abstract: We studied, in different ionic conditions, the effect of various agents on the membrane potential of rat peritoneal mast cells using the fluorescent probe bisoxonol. Ouabain and ionophore A23187 lead to a fast depolarization of the plasma membrane of mast cells, while compound 48/80 and thapsigargin induced membrane hyperpolarization, which was more pronounced in the case of compound 48/80. When using compound 48/80, the amount of gramicidin necessary to depolarize the cells was twice the amount required in resting cells, which indicates that compound 48/80 increases considerably the activity of the Na+/K+ pump. On the other hand, the ionophore A23187 elicited a clear depolarization which was oblated in the absence of intracellular calcium. The increase in the osmolarity of the medium causes a depolarization in the plasma membrane of mast cells. Hypertonicity-stimulated depolarization is inhibited by removing sodium and potassium.
authors.affiliation: Departamento de Farmacología, Facultad de Veterinaria, Universidad de Santiago, Lugo, Spain.
authors.forename: A G
authors.initials: AG
authors.lastname: Cabado
authors.forename: M R
authors.initials: MR
authors.lastname: Vieytes
authors.forename: L M
authors.initials: LM
authors.lastname: Botana
mesh_terms: D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D005456:Fluorescent Dyes; D006096:Gramicidin / Q000494:pharmacology; D007477:Ions; D008407:Mast Cells / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology*; D008564:Membrane Potentials; D051381:Rats; D017207:Rats, Sprague-Dawley; D013729:Terpenes / Q000494:pharmacology; D019284:Thapsigargin; D013858:Thiobarbiturates; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
chemical_list: D005456:Fluorescent Dyes; D007477:Ions; D013729:Terpenes; D013858:Thiobarbiturates; D006096:Gramicidin; D000001:Calcimycin; D003189:p-Methoxy-N-methylphenethylamine; C025284:bis(1,3-diethylthiobarbiturate)trimethineoxonol; D019284:Thapsigargin; D000252:Calcium-Transporting ATPases