[Participation of cyclic nucleotides and calcium in regulation of the sensitivity of vertebrate photoreceptors]. / Ob uchastii tsiklicheskikh nukleotidov i kal'tsiia v reguliatsii chuvstvitel'nosti fotoretseptorov pozvonochnykh.

Effects of PDE inhibitor IBMX and of Ca2+ decrease upon sensitivity of rods and cones were compared. IBMX greatly increases the sensitivity of rods but not that of cones. Ca2+ does not significantly affect the sensitivity of both rods and cones. Possible role of cyclic nucleotides as feed--back regulator in mechanisms of photoreception is discussed.