title: Effect of illuminated nifedipine, a potent antioxidant, on intestinal and vascular smooth muscles.
abstract: 1. The effects of nifedipine (Nif) and its illuminated nitroso product nitrosopine (NTP) were investigated on lipid peroxidation, KCl elevated smooth muscle tension, and ionic currents of single smooth muscle cells. 2. Illumination of Nif at 400-700 nm within 24-48 h changed it completely to a potent antioxidant, NTP. 3. Nif relaxed the KCl-induced contractions of guinea-pig taenia caeci and rat aorta and reduced the amplitude of the evoked inward Ca2+ current of taenia caeci cells in a concentration-dependent manner. NTP (up to 100 microM) was ineffective in this respect. Pretreatment by NTP (10 microM) did not affect the actions of Nif. 4. The evidence suggests that NTP, generated by day-light illumination from Nif, exerts antioxidant activity but is devoid of voltage-dependent Ca2+ channel (VDC) blocking property and does not interfere with the action of Nif on the smooth muscle cell membrane VDC.
authors.affiliation: Institute of Experimental Pharmacology, Slovak Academy of Sciences, Bratislava.
authors.forename: V
authors.initials: V
authors.lastname: Bauer
authors.forename: V V
authors.initials: VV
authors.lastname: Rekalov
authors.forename: I
authors.initials: I
authors.lastname: Juránek
authors.forename: D
authors.initials: D
authors.lastname: Gergel
authors.forename: P
authors.initials: P
authors.lastname: Bohov
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000187:drug effects; D002849:Chromatography, Gas; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D007422:Intestines / Q000098:blood supply / Q000187:drug effects*; D015227:Lipid Peroxidation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D009543:Nifedipine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
chemical_list: D000975:Antioxidants; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D009543:Nifedipine