MUSCARINIC CHOLINERGIC AND PREGANGLIONIC PHYSIOLOGICAL STIMULATION INCREASE CYCLIC GMP LEVELS IN GUINEA‐PIG SUPERIOR CERVICAL GANGLIA1

Abstract
Abstract— Incubation of guinea‐pig superior cervical ganglia in 500μ4mUm‐carbachol for 2min increased cyclic GMP levels 530% over control values. The increase was blocked by prior incubation in 300μmatropine. No increase in cyclic GMP levels after incubation in 100 μm‐l‐norepinephrine was observed. Preganglionic physiological stimulation for 8 min at 10 Hz increased cyclic GMP levels 180% over control values. We conclude that both muscarinic cholinergic and preganglionic physiological stimulation increase cyclic GMP levels in guinea pig superior cervical ganglia, while norepinephrine has no effect.
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