The effects of 5-hydroxytryptamine and glutamate on muscle contraction in Hymenolepis diminuta (Cestoda)

Abstract
Contractions of the longitudinal musculature from strobilae of the rat tapeworm Hymenolepis diminuta were measured by means of a force transducer. Stretching caused an increase in both the rate and the amplitude of spontaneously occurring contractions while brief stretches could elicit contractions in quiescent preparations. The application of 5-hydroxytryptamine (serotonin) produced variable results; in some preparations there was an increase in the frequency, but not the amplitude, of spontaneous contractions, while in others there was a decrease in both frequency and amplitude of spontaneous contractions. The application of glutamate elicited powerful contractions of the longitudinal muscles in all preparations and restored rhythmic contractions to quiescent preparations.
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