1. 1. The muscle was isolated from the southern whelk, Busycon contrarium. 2. 2. Dopamine (DA) elicits a single phasic contraction that is rapidly desentisized at high drug concentrations. Such desensitized preparations still respond to acetylcholine (ACh) and the molluscan neuropeptide FMRFamide. The evidence suggests the existence of an excitatory DA receptor. 3. 3. Muscles in FMRFamide or ACh contraction are relaxed by 5-hydroxytryptamine, phenylethylamines and catecholamines in a dose-dependent manner; a single phasic contraction precedes the catecholamine relaxation of such muscles. 4. 4. The responsesto FMRFamide, ACh and DA are sodium dependent; FMMFamide responses are more calcium dependent than ACh or DA.
|Original language||English (US)|
|Number of pages||5|
|Journal||Comparative Biochemistry and Physiology. Part C, Comparative|
|State||Published - 1982|
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