Effects of temperature on tadpole hearts in vitro

Abstract

ABSTRACT Whole hearts of tadpoles of Limnodynastes peroni were cultured successfully in a combined avian-synthetic medium identical with that used for mammalian, avian and reptilian tissues. The extirpated hearts were cultured from 37 to 5°C. Temperature effects on organ viability and function and on cell outgrowth were studied comparatively. Although viability could be maintained for up to 6 days at 37°C, this temperature was ultimately lethal. From 30 to 5°C inclusive total viability or maintenance was the general rule. Rate of heart beat was at first accelerated at 37°C but dropped as moribund conditions developed. For the other temperatures used, though absolute values varied considerably, a more or less constant relative pattern emerged, with the optimal rate at 30°C and successive decreases occurring from 25 to 5°C. Cell migration did not occur at 37 or 5°C. The optimal temperature for outgrowth was 30°C, while progressively slower migration occurred from 25 to 15°C. At 8°C, outgrowth was confined to a few cells in a limited number of cultures. Although these results apply at present to only one species, the establishment of 30°C as an optimal incubation temperature may be important in view of the fact that almost all previous amphibian cultures have been grown at temperatures not exceeding 26°C and often considerably lower.