The Effect of Temperature on Potassium Equilibria in Chick Embryo Muscle

Abstract

Cohn and Brues (2) have described a technique employing radioactive isotopes by means of which the rate of exchange of potassium and phosphate ions between the intra-and extracellular phases of tissue cultures could be measured. In the present paper, this technique is employed to study rates of exchange of potassium in chick embryo muscle cultures at different temperatures, and also to study the effect of lowering temperature on the total amount of potassium contained within the cells of cultures. Methods and CalculationsMinced leg muscle taken from chick embryos of 9 to 11 days' incubation was explanted in a thin plasma dot on the window of a roller bottle, as described by Shaw, Kingsland, and Brues (3). The medium consisted of 4 ml. of modified Baker's peptone medium (4). The explant was allowed to incubate overnight at 37°C. to permit injured ceils to repair or disintegrate. At the start of an experiment, the medium was exchanged for one containing radioactive potassium (K4~), but otherwise of identical composition. Radioactivity in the culture was measured at 15 to 60 minute intervals by means of a Lauritsen dectroscope or Geiger-Muller counter placed opposite the window of the culture bottle. The direct measurements of radioactivity external to the window were used to determine the actual amount of K 42 in the cultured cells during the course of the experiment, by a method described previously (2). At the end of the experiment, the medium was withdrawn and, when necessary, activity measurements were made and total potassium determined on the medium. When tissue analyses were desired, the tissue was washed twice in situ by gentle rocking with 0.85 per cent saline solution for 15 seconds, then removed, ashed with nitric acid, and analyzed for radioactivity and potassium content. Total potassium was determined according to the method of Shohl and Bennett (5) as modified by Hald (6). From these final analyses, the relative specific activity (SA) of the tissue mass at the termination of the experiment was determined, and its specific activity during the course of the experiment was calculated from the readings. Determinations of the rate of radioactive potassium uptake were made at 37 °, 26 °, 15 °, 10 °, and 5 °.

Current Issues and Technical Advances in Cultured Meat Production: A Review

“…To overcome these ` shortcomings, relevant efforts have been made to automate the roller bottle-based culture process (Kunitake et al, 1997). Roller bottles have been used to culture chicken muscle cells in large scale (Wesson et al, 1949) which may be applied for chicken meat production.…”

“…To overcome these shortcomings, relevant efforts have been made to automate the roller bottle-based culture process ( Kunitake et al., 1997 ). Roller bottles have been used to culture chicken muscle cells in large scale ( Wesson et al, 1949 ) which may be applied for chicken meat production. According to USDA, roller bottle incubator systems drastically improved swine muscle cell production output, providing enough cells for three-dimensional (3D) fabrication of cellular sheets for in vitro meat engineering ( Marga, 2012 ).…”