 |
|||
Table 5: Ringer's Recipes - Invertebrates Table 6: Ringer's Recipes - Fish Table 7: Ringer's Recipes - Other Vertebrates
Ringer's analysis of the influence of blood constituents on contraction of the frog heart (1882-1885) pioneered general development of artificial extracellular media for maintenance of living material during in vitro physiological studies. "Ringer's solutions" are thus defined here as those designed to substitute for the blood plasma, hemolymph, or other extracellular fluids of any species with respect to variables such as ionic concentrations, pH, and osmotic pressure. Media described in the literature as "physiological salines" and "balanced salt solutions" are included here under the general Ringer's heading. Mimicry of native conditions is achieved in varying degrees by the many different Ringer's formulations. Ringer's solutions are typically intended for relatively short-term maintenance of living material, not for its growth or extended culture. In this respect they differ from cell, tissue, and organ culture media, which are more complex and beyond the scope of this Compendium. Since Na+ is normally the principal extracellular ion, sodium chloride is the major component of most Ringer's solutions. Some formulations have relatively few additional ingredients but are nevertheless more complex than most "buffered salines", consisting principally of sodium chloride and a pH buffer, presented in another section (V; Table 8). Many of the Ringer's solutions used experimentally are listed in Table 4, which is divided into sections for Invertebrates, Fish, and Other Vertebrates. Recipies for their preparation are provided in Tables 5, 6, and 7, respectively. Additional details on Ringer's characteristics and usage may be found in Notes and Literature Cited; for further information, the comprehensive work by Burton (1975) is recommended. Ions such as Na+, K+, Ca++, and Mg++ are critical for many functions. Researchers initiating work are urged to select physiological solutions carefully for the particular species to be studied, and to consider developing new ones based on analysis of the natural extracellular medium. Many Ringer's solutions are the product of empirical testing for retention of the activity being studied. Thus, in addition to being used directly, recipes provided here can serve as a starting point for improved formulations.
|
|||
