MEASUREMENT OF INTRACELLULAR PH IN MAMMALIAN SPERM CELLS UNDER PHYSIOLOGICAL CONDITIONS

The goal of this study was to develop a technique for the measurement of intracellular pH (pH(i)) in living mammalian (bovine) sperm cells under physiological conditions, Like many other biochemical measurements, pH(i) measurements have typically been made under non-physiological conditions on cells whose immediate functional status is not readily assessed and may even be non-viable, Additionally, many pH(i) measurement techniques may themselves alter the pH(i) of the cells being measured. Such measurements could yield misinformation. The sperm cell is unique in that its functional status can be easily and continuously monitored by means of its motility, which is directly affected by pH(i). In this respect, the sperm cell provides an ideal model system for evaluating pH(i) measurement techniques. In this article we summarize the validation of a ratiometric absorbance technique for the measurement of pH(i) of mammalian (bovine) sperm cells under physiological conditions which does not affect their functional status, The pH(i) of ejaculated bovine sperm cells was calculated to be 6.9 +/- 0.05 (11 replicates). This approach may also be suitable for pH(i) measurements in other cell types. (C) 1995 Wiley-Liss, Inc.