Water and electrolytes in muscle tissue and free amino acids in muscle and plasma in connection with transurethral resection of the prostate. I. Distilled water as an irrigating fluid.

10 patients undergoing transurethral resection of the prostate using sterile distilled water as an irrigating fluid were studied. The extra- and intracellular distribution of water, the total content of water and electrolytes and the free amino acid concentrations in muscle tissue were determined together with the concentrations of free amino acids in plasma preoperatively, immediately postoperatively and 2 hours postoperatively. The content of water and concentrations of electrolytes in skeletal muscle did not change significantly from the preoperative to the postoperative period with the exception of the potassium concentration, which decreased 2 hours postoperatively. The following free amino acid concentrations in muscle tissue showed significantly decreased values 2 hours postoperatively compared with the preoperative values: taurine, serine, glutamate, proline and leucine. The concentrations of non-essential amino acids in muscle decreased significantly 2 hours postoperatively. This may be interpreted as a dilution effect. An increased concentration of some amino acids in plasma postoperatively may be explained as a haemoconcentration effect due to the use of a postoperative diuretic.