Introduction and objective:
Compared to the general population, patients with end-stage renal disease (ESRD) are more likely to have neurological conditions, such as memory impairments. It is thought that the cognitive impairment may affect 30% – 80% of patients with ESRD. Patients on haemodialysis are especially vulnerable to the biological effects of uraemic toxins. It has been suggested that one of the uraemic toxins most likely to affect cognitive function in patients with ESRD is indoxyl sulfate (IS). The aim of the study is to investigate the potential effect of IS on memory consolidation.

Material and methods:
Adult male Swiss mice were used in the study. Memory consolidation was assessed in the stepthrough passive avoidance test. Indoxyl sulfate potassium salt (IS) and scopolamine hydrobromide (SCO) were employed in the experiments. IS (200, 400 mg/kg) and SCO (1 mg/kg) were given intraperitoneally (i.p.). Each drug was administered as a single injection. Additionally, acetylcholinesterase (AChE) activity was determined in the brain following applied drug treatments.

Results:
IS administration (200 and 400 mg/kg i.p.) alone and in combination with SCO (1 mg/kg i.p.) did not affect memory consolidation in the passive avoidance test. Exposure to IS did not significantly alter the activity of AChE in the brain tissue.

Conclusions:
This study shows that acute exposure to IS does not impair memory consolidation in mice. Chronic exposure to IS in animals is necessary to obtain additional information concerning the toxin’s effects on memory consolidation.