[Photo-induced release of calcium ions frog retina photoreceptor membranes in media of different ionic composition].
Two methods: labelled Ca45 and Ca++-selective electrode served to assess the Ca++ release during illumination of the rod outer segments in the frog retina. The maximal release (8--10 M Ca++/M bleached rhodopsin) occurred in monovalent cations--free medium (100 MM tris--HCl, 5 mM MgCl2, 5 mM ATP, pH--7.5), when at least 50% of visual pigment was bleached. The addition of Na+ or K+ toincubation medium decreased the photoinduced release to 0.06--0.142 M Ca++/M bleached rhodopsin or completely suppressed it. The role of Ca++ as a messenger during the excitation of photoreceptor is discussed.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D066298:In Vitro Techniques; D008027:Light; D010786:Photoreceptor Cells / Q000378:metabolism*; D011188:Potassium / Q000494:pharmacology; D011896:Rana temporaria; D012243:Rhodopsin / Q000528:radiation effects; D012374:Rod Cell Outer Segment / Q000378:metabolism* / Q000528:radiation effects; D012964:Sodium / Q000494:pharmacology
D000255:Adenosine Triphosphate; D012243:Rhodopsin; D012964:Sodium; D011188:Potassium; D002118:Calcium
Fotoindutsirovannyĭ vykhod ionov kal'tsiia iz fotoretseptornykh membran setchatki liagushki v sredakh razlichnogo ionnogo sostava.