Schistosoma mansoni: a comparison of male and female muscle physiology.

Surface electrical activity and membrane potentials recorded from male and female Schistosoma mansoni are similar. Surface electrical activity and responses to electrical stimulation are slightly higher in females. Contractures induced by praziquantel, 60 mM K+, ouabain or 5 degrees C are slightly less in females but responses to putative neurotransmitters (5-HT, dopamine and carbachol) are the same in both sexes. Females are more susceptible to the removal of Ca2+ and to the increase of Mg2+ in the medium. These differences may be due to anatomical differences in the sexes or to the recording methods used.