Development of the heartbeat during normal ontogeny and during long-term organ culture of hearts of the newt, Cynops pyrrhogaster.
Development of cardiac contraction was investigated in the newt, Cynops pyrrhogaster, during normal development and in hearts maintained in long-term organ culture. In the embryos the heart began beating as early as stage 33. The heart rate increased up to stage 52 and then gradually decreased to the adult rate by stage 60. The heart rate showed a logarithmic temperature dependence. In organ-cultured hearts the pattern of heart rate depended on the stage at which the heart was explanted; cultured embryonic hearts showed a pattern of increase and decline similar to that seen in vivo, and hearts explanted near metamorphosis showed only a slow decline.
Department of Biology, Yokohama City University, Japan.
M
M
Taguchi
M
M
Uehara
M
M
Asashima
C J
CJ
Pfeiffer
D000818:Animals; D005260:Female; D006321:Heart / Q000196:embryology*; D006339:Heart Rate; D009924:Organ Culture Techniques; D012455:Salamandridae / Q000196:embryology*; D013696:Temperature