Pharmacological control of muscular activity in the sea urchin larva. III. Role of cyclic nucleotides.
1. The muscular activity of the sea urchin pluteus is strongly affected by dibutyryl-c-AMP, in a stimulatory or inhibitory manner depending on the concentration, the time of exposure, and the spontaneous level of activity. 2. Dibutyryl-c-GMP, like muscarinic agents and the guanylate-cyclase activators biotin and nitrite, keeps the activity low. 3. It is suggested that the effects of muscarinic agents is mediated by c-GMP, the effects of certain monoamines by c-AMP. 4. The two cyclic nucleotides appear to control the cellular influx of Ca2+ in opposite directions. They therefore interfere with the stimulatory and paralytic effects of nicotinic agents.
Wenner-Gren Institute, Biologihus F3, University of Stockholm, Sweden.
T
T
Gustafson
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D000242:Cyclic AMP / Q000494:pharmacology; D003995:Dibutyryl Cyclic GMP / Q000494:pharmacology; D004789:Enzyme Activation; D005731:Ganglionic Stimulants / Q000494:pharmacology; D006162:Guanylate Cyclase / Q000378:metabolism; D007814:Larva; D009132:Muscles / Q000502:physiology*; D009712:Nucleotides, Cyclic / Q000494:pharmacology / Q000502:physiology; D010277:Parasympathomimetics / Q000494:pharmacology; D012617:Sea Urchins / Q000502:physiology*
D005731:Ganglionic Stimulants; D009712:Nucleotides, Cyclic; D010277:Parasympathomimetics; D003995:Dibutyryl Cyclic GMP; D003994:Bucladesine; D000242:Cyclic AMP; D006162:Guanylate Cyclase; D002118:Calcium; D015056:1-Methyl-3-isobutylxanthine