Summary: The activities of alanine aminopeptidase (AAP),
g-glutamyltransferase (GGT) and N-acetyl-b-D-glucosamini –
dase (NAG), enzymes dominantly localised in the epithelial
proximal tubule cells, were measured with an aim of deter –
mining the nephrotoxicity of a cephalosporin antibiotic cep h –
a lexin. Enzymatic activities were measured in the 12-h urine
sam ples of patients receiving cephalexin orally for 15 days in
daily doses of 50 mg/kg body mass against Gram-positive
infections of the respiratory or urinary tract. The same enzy –
mes were determined in the 12-h urine samples of the
corresponding control. Both the control and the expe ri mental
group consisted of 30 examinees of both sexes, age range
3–10 years. Sta tistically significant differences in AAP and
GGT activities expressed as U/mmol creatinine were recor –
ded after 12 days of cephalexin therapy in comparison with
the control (p < 0.01). At the same time, no significant
differences in NAG activity of the patients in relation to the
control were observed during the entire course of the therapy.
Based on the obtained results it can be concluded that
treatment of 3–10 years old patients with the applied ceph –
alexin doses for 15 days results in mild nephrotoxic changes
close to the end of therapy accompanied by incre ased
activities of AAP and GGT, the enzymes known as very sen si –
tive indicators of nephrotoxicity. The results showing that
during the entire period of cephalexin appli cation no changes
in NAG, as a lysosomal enzyme, were observed, could be
taken as a proof that this antibiotic did not lead to severe
injuries of epithelial proximal tubule cells at the level of cell
organelles.
