Bochkin L M, Zak P P, Ostrovskii M A
Fiziol Zh SSSR Im I M Sechenova. 1985 Jul;71(7):848-55.
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.