Influence of the Temperature upon the Life Duration and the Growth of the Fibroblast Cultivated in vitro

Abstract

(1) The fragments of heart muscle of the chicken embryo incubated at 39° for 8 or 9 days were embedded in the culture medium, composed of equal volumes of the hen plasma and the embryonic tissue juice.
All the cultures underwent 5 or 7 passages and then were kept in the incubator 39° for one day.
Then the plates with the tissue fragments were placed in the incubators at various temperatures, i. e. 45°, 39°, 30°, 20°, 12° and 5°. In every medium one fragment was cultivated or two together. The outline of the total area of the new cells was traced every day, thus the degree of growth at various temperatures was determined. After the lapse of a certain length of time the culture was transferred into a fresh medium and put into an incubator at 39°, to determine whether the tissue was living or not.
(2) The degree of growth was largest at 39°, the next at 30° and the smallest one was found at 45°.
The tissue kept at 20°, 12° and 5° did not grow at all.
(3) In the cases where one tissue fragment was cultivated in one medium, the temperature coefficients of the degree of growth at 39° and 30° were 2.0-2.4 in the interval of a few days, during which the tissues continued to grow both at 39° and 30°. The Q₁₀ values between 45°and 39° were smaller than unity (0.5 to 0.2) and diminished as the life duration in vitro advanced.
(4) In the cases with two fragments in each medium the Q₁₀ values were smaller than those of the above between 39° and 30° and sometimes after a few days' life in vitro it became smaller than unity. Between 45° and 39° it was the same as that with one fragment in each medium.
(5) The maximum interval, in which all the fragments were kept alive, when the medium remained unaltered, was estimated as 1 day at 45°, 7 days at 39°, 12 days at 30°, 11 days at 20°, 6 days at 12° and 3 days at 5°.
The longest life duration for one fragment in each medium was noted as 5 days at 45°, 11 days at 39°, 20 days at 30°, 14 days at 20°, 11 days 12° and 8 days at 5°, and that in the cases with two fragments 5 days at 45°, 9 days at 39°, 16 days at 30°, 12 days at 20°, 7 days at 12° and 7 days at 5°.
(6) The temperature coefficients of the number of days of life duration were the highest at low temperature (2.0 between 20° and 12°) and the more temperature was heightened, the smaller they became.