Hm. Jin et al., Effects of commercial glucose-based peritoneal dialysates om peripheral blood phagocytes apoptosis, PERIT DIA I, 19, 1999, pp. S388-S393
Background:Variable glucose-lactate-based peritoneal dialysates have negati
ve effects on peritoneal macrophages and peripheral blood leukocytes, reduc
ing the capacity of leukocytes for chemotaxis, bacterial killing. But few r
eports exist on cell apoptosis. To investigate the effects of glucose-lacta
te-based peritoneal dialysates on cultured phagocytes (monocytes and neutro
phils), we focused on studying phagocyte apoptosis after brief exposure to
commercial peritoneal dialysates.
Methods: Cell apoptosis is measured by flow cytometry (FCM) to detect phosp
hatidylserine (PS) exposure on early apoptotic cells using fluorescein-labe
led annexin V.To mimic the composition of dialysate in vivo, where the fres
hly instilled solution mixes with the residual dialysate from the previous
cycle, we performed the experiments using a mixture of fresh and spent dial
ysate (9:1). In our transient exposure experiments, monocytes and neutrophi
ls were separately incubated in each of the test solutions (1.5% glucose an
d 4.25% glucose dialysates) for 10 minutes or 30 minutes and afterward sepa
rated and resuspended in RPMI 1640 medium and cultured over the indicated t
ime.
Results: After exposure to 1.5% glucose dialysates for 10 minutes, monocyte
s and neutrophils exhibited normally spontaneous apoptosis. After exposure
to 4.25% glucose dialysate, monocytes underwent apoptosis increasingly, 21%
+/- 5.0% versus 9.8% +/- 3.6% (p < 0.05) at 24 hours and 47% +/- 6.2% vers
us 16% +/- 4.0% (p < 0.01) at 72 hours compared with controls. For neutroph
ils, the results were discouraging: hypertonic dialysate not only increased
apoptosis [65.36% +/- 2.6% versus 34.17% +/- 8.52% (p < 0.01) at 72 hours]
, but also induced cell necrosis. When incubation time was prolonged for 30
minutes, 1.5% dialysate acted like 4.25% dialysate, with the rate of apopt
osis increasing rapidly [40% +/- 4.0% versus 16% +/- 4.0% (p < 0.01) at 72
hours for monocytes, and 66.90% +/- 5.6% versus 34.17% +/- 8.52% (p < 0.01)
at 72 hours for neutrophils].
Conclusion: Glucose-lactate-based peritoneal dialysates can induce peripher
al blood phagocyte apoptosis in vitro, which indicates that glucose plays a
n important role in triggering cell apoptosis. Therefore, looking for new,
physiologic peritoneal dialysis fluids to replace conventional fluids is re
asonable.