Locke Solution

Locke Solution. (Locke), a solution used to maintain the viability of isolated or blood-deprived organs, which is a modification of Ringer's solution. Locke solution is often called Ringer-Locke solution. To obtain a liquid that would maintain the functioning of an isolated warm-blooded heart for a prolonged period, Locke proposed adding glucose (dextrose) to Ringer's solution and constantly passing a weak current of oxygen through the solution. Glucose provides easily combustible nutritional material to the tissues, while passing O₂ promotes better oxidation of the breakdown products formed during the activity of organs. The composition of Locke's solution is as follows: per 1,000 cm³ of water - 9 g NaCl, 0.42 g KCl, 0.24 g CaCl₂, 0.1-0.3 g NaHCO₃ (not Na₂CO₃!) and 1.0-2.5 g glucose. The presence of traces of heavy metals has a poisonous effect. Using this solution, Locke was able to maintain the activity of an isolated warm-blooded heart for 4 days at the International Congress of Physiologists in 1901. For a warm-blooded heart, L. s. is apparently the best. For other organs, various authors have given different recipes. Often MgSO₄ (0.03-0.05%) and especially Na₂HPO₄ (0.05%) are added. The content of KCl and CaCl₂ is often reduced to 0.02% (0.2 g each per 1,000 cm³ H₂O). Lit.: Rubinshtein D., Introduction to Physical-Chemical Biology, pp. 62-65, M.-L., 1925; Luck with F., Towards the ideal artificial circulating fluid for the isolated frog's heart, Journ. of physiology, v. XVIII, 1895.