title: Synergism of ochratoxin B and calcium-channel antagonist verapamil caused mitochondrial dysfunction.
abstract: We examined the mechanism by which the ochratoxin B induced interaction with calcium-channel antagonist verapamil and mitochondrial dysfunction of the rat trachea in vitro experiment. The tracheas were cut into 2-3 mm wide rings and suspended in a tissue bath. Isometric tension was continuously measured with an isometric force transducer connected to a computer-based data acquisition system. Verapamil (1 × 10(-6) M) produced a concentration-dependent contraction response in rat's tracheal rings pre-contracted by acetylcholine. Incubation of rat's tracheal rings with the ochratoxin B significantly potentiated the contraction responses of verapamil. Verapamil and OTB accelerate the overloading of Ca(2+) in tracheal smooth muscle contributes the tissue toxicity as shown in electron microscopy and mitochondrial enzymes, through a mechanism that could involve perturbations of Ca(2+) homeostasis. These results proved that ochratoxin B is a potential vasoconstrictor mycotoxin with the presence of calcium-channel antagonist. In conclusion, disturbance of Ca(2+) homeostasis caused by OTA and plays a significant role in produces toxicity through mitochondrial enzyme inhibition.
authors: Defence Research Laboratory , Tezpur, Assam , India and.
authors: Pronobesh
authors: P
authors: Chatopadhyay
authors: Banlumlang
authors: B
authors: Tariang
authors: Amit
authors: A
authors: Agnihotri
authors: Vijay
authors: V
authors: Veer
mesh_terms: D000818:Animals; D002121:Calcium Channel Blockers / Q000008:administration & dosage / Q000633:toxicity; D004357:Drug Synergism; D008928:Mitochondria / Q000187:drug effects* / Q000201:enzymology; D009793:Ochratoxins / Q000008:administration & dosage* / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D046509:Tissue Culture Techniques; D014132:Trachea / Q000187:drug effects / Q000648:ultrastructure; D014700:Verapamil / Q000008:administration & dosage* / Q000633:toxicity*
chemical_list: D002121:Calcium Channel Blockers; D009793:Ochratoxins; D014700:Verapamil; C045354:ochratoxin B
keywords: Ca2+ channel blocker; intercellular Ca2+; ochratoxin B