The effect of adaptation temperature on the properties of nerve muscle preparations and on the performance of the frograna temporaria L

Kurzfassung

Ziel der vorliegenden Untersuchung war die Beantwortung der Frage, ob sich bei kaltadaptierten und warmadaptierten Fröschen Unterschiede an Nerv-Muskel-Präparationen nachweisen lassen. Die Versuchstiere wurden an 10° bzw. 22° C adaptiert. Danach wurden dann bei 20° C in vitro Messungen am Gastrocnemius-Muskel und den ihn versorgenden Nerven durchgeführt. Weder in den Charkateristika der Einzelkontraktion noch des Tetanus konnten Unterschiede festgestellt werden. Auch hinsichtlich des Springvermögens intakter Individuen ließen sich keinerlei Unterschiede nachweisen. Die Bedeutung dieser Ergebnisse wird diskutiert.

Summary

1. Comparisons were made between the characteristics of nerve muscle preparations measured at 20° C from 22° and 10° C adapted frogs. In the maximum single isometric twitches no significant difference was found in latent period, contraction time, or relaxation time between the two groups. There was a barely significant difference (P = 0.05) in tension developed/gram muscle but it was thought that with a larger number of experiments no true difference would be found.

2. With isometric tetanus again no difference was found between the 10° and 22° C adapted frogs, either in tension developed or in fatigue time.

3. The jumping performances were measured in intact 10° and 22° C adapted frogs brought to 18° C for 10 minutes and then measured at this temperature. No significant difference could be found between the two groups. The significance of the results is discussed.