Assay of plasma glycine by HPLC with electrochemical detection in patients undergoing glycine irrigation during gynaecological surgery.

A method for the measurement of plasma glycine by HPLC with electrochemical detection after derivatization with phenylisothiocyanate (PITC) is described. The absorption of glycine in eighteen women undergoing intrauterine glycine irrigation during transcervical resection of endometrium was assessed by measurement of plasma glycine before, immediately after and 24 h after surgery. The plasma glycine concentration was normal in all women before surgery (range 120-386 mumol/l) but had risen dramatically in some patients after surgery (range 180-24,800 mumol/l) before returning to normal levels over the following 24 h (range 173-553 mumol/l). No clinical consequences were observed despite the large increases in plasma glycine; mild hyponatraemia occurred in only one patient. These findings, albeit in a limited number of patients, support the hypothesis that the symptoms sometimes associated with the use of glycine buffers are most likely due to water overload with hyponatraemia rather than a toxic affect of glycine itself.