If a drug inhibits the hydrolysis of cGMP in retinal photoreceptors, which consequence follows for phototransduction in the eye?

💡 Explanation

Inhibiting cGMP hydrolysis means cGMP levels remain high, keeping sodium channels open, which maintains the rod cell in a depolarized state. Because the phosphodiesterase (PDE) mechanism that breaks down cGMP is blocked, the cell remains depolarized, therefore prolonged depolarization occurs, rather than hyperpolarization or altered rhodopsin activity.

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