Table II Kinetics of PDE Activation and... | Rockefeller University Press

Table II

Kinetics of PDE Activation and Inactivation in Retinal Photoreceptors

	β_dark	\(N_{d}^{{\ast}}\)	N₀	\(N_{d}^{{\ast}}\) /N₀	k_a	τ⁻¹	τ
	s⁻¹				s⁻¹	s⁻¹	s
Bass cone	0.24	60	3 × 10⁶	1/5 × 10⁴	0.17 × 10⁻⁴	0.84	1.19
Rod	1–2^{^a}^{^b}	487	2 × 10⁷	1/4 × 10⁴	0.27 × 10⁻⁴^{^b}	1.8 ^{^b}	0.55

	β_dark	\(N_{d}^{{\ast}}\)	N₀	\(N_{d}^{{\ast}}\) /N₀	k_a	τ⁻¹	τ
	s⁻¹				s⁻¹	s⁻¹	s
Bass cone	0.24	60	3 × 10⁶	1/5 × 10⁴	0.17 × 10⁻⁴	0.84	1.19
Rod	1–2^{^a}^{^b}	487	2 × 10⁷	1/4 × 10⁴	0.27 × 10⁻⁴^{^b}	1.8 ^{^b}	0.55

\(N_{d}^{{\ast}}\)

⁠, number of active PDE molecules in the dark; N₀, total number of PDE molecules in the outer segment (1/70 PDE/VP, Zhang et al., 2003); k_a, PDE forward activation rate; τ⁻¹, PDE backward activation rate

\({\tau}{=}1/k_{a}{+}{\tau}^{{-}1}\)

active PDE lifetime.

Hodgkin and Nunn (1988) and Nikonov et al. (2000), in tiger salamander retina.

Rieke and Baylor (1996), in toad retina.

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