Type of electrical stimulation influences diaphragm response to adrenoceptor and calcium channel modulators: the role of extracellular and intracellular calcium events.
The influence of direct single pulse and subtetanic electrical stimulation (ES) on isolated rat hemidiaphragm response to adrenoceptor antagonists and calcium channel blockers was investigated. Muscle contractility was stimulated by cumulative micromolar noradrenaline. Noradrenaline effects on developed tension (Td) in the presence of various alpha- and beta-adrenoceptor antagonists (e.g., prazosin and ICI 118551) were qualitatively different during different types of ES. Also, intact L-voltage calcium channels were necessary for noradrenaline-induced potentiation of Td during both types of ES, while the balance between ryanodine receptors- and inositol triphosphate (IP3)-related calcium events in the muscle was influenced by the pattern of the ES.
Todorovic
Zoran
Z
Department of Pharmacology, Clinical Pharmacology and Toxicology, School of Medicine, University of Belgrade, Belgrade, Serbia and Montenegro.
Stojanovic
Radan
R
Nesic
Zorica
Z
Divac
Nevena
N
Vojvodic
Nikola
N
Cerovac-Cosic
Natasa
N
Prostran
Milica
M
D018663:Adrenergic Agents / Q000494:pharmacology*; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D002120:Calcium Channel Agonists / Q000494:pharmacology*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D003964:Diaphragm / Q000187:drug effects; D004558:Electric Stimulation; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D006493:Heparin / Q000494:pharmacology; D066298:In Vitro Techniques; D042541:Intracellular Space / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D017711:Nonlinear Dynamics; D051381:Rats; D017208:Rats, Wistar; D012132:Respiratory Muscles / Q000187:drug effects / Q000502:physiology*; D019837:Ryanodine Receptor Calcium Release Channel / Q000187:drug effects
D018663:Adrenergic Agents; D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D002120:Calcium Channel Agonists; D002121:Calcium Channel Blockers; D019837:Ryanodine Receptor Calcium Release Channel; D006493:Heparin