Adhesions of the fallopian tube might be a source of generalized infertility. In order to improve the mechanical and functional properties of the oviduct, microsurgical replacement of the affected tubular segments have been applied, however, with contradictory results. In order to improve the situation and gain further information about this problem, catheter microelectrodes for Po2 and pH measurements within the lumen of the fallopian tube have been developed. The validity of the measurements was tested in a series of rabbits (Dutch belt strain, n = 19, 3.5-4.5 kg bw) which have been laparatomized under pentobarbital anesthesia during the oestrus phase. From one side of the oviduct 1 cm was resected and the free ends reanastomosed while the other side served as a control. Six to eight weeks later Po2 and pH values within the oviduct were measured. After another 4-5 weeks ovulation had been induced and artificial insemination performed. 64 hours later the rabbits were sacrificed. The oviducts were isolated and the corpora lutea as well as the ova were collected and examined histologically. The mean Po2 of the oviduct was 53 (+/- 16) mm Hg (mean +/- SD) for the control side and 56 (+/- 13) mm Hg (mean +/- SD) within the anastomosed tubes. The range of values was the same in both groups (n = 8) 34-75 mm Hg. A T-test comparison of the means of the two groups gave p-values which were not significant (p greater than 0.1). Po2 fluctuations with small-fast amplitudes (1 mm Hg) and additional slow-large oscillations (about 20 mm Hg) have been observed similar to the Po2 waves described for muscle and brain. The mean pH value of the oviduct a showed slight, statistically significant pH differences (7.75 reanastomosed side, 7.94 control side) whereby the degree of adhesions was correlated with luminal pH value. In three rabbits the relationship between corpora lutea and fertilized ova was 1:6, 2:9, 3:6 for the reanastomosed side while the control side showed balanced quotients of 4:4, 4:4, 6:6. In two rabbits unfertilized ova have been observed within the reanastomosed tubes where the typical outside layer of mucoproteids was absent while the control side was normal. Nevertheless, within both oviducts a continuous layer of epithelial cells has been observed even after reanastomosis.