Presence of tobramycin in kidneys and placentae of Sprague-Dawley rat fetuses and newborns following in utero exposure.
The maternal-fetal transfer of tobramycin (TBM) was investigated in the rat by means of a microbiological assay, to assess the presence and amount in the kidneys and placentae of fetuses at gestational day (GD) 20, in the kidneys of newborns 6 and 11 days after the end of treatment and in the kidneys of the dams. In the qualitative assay, pregnant rats were injected i.p. with 0, 30, 60 mg/kg b.w. of TBM on GD 10-19. A group of dams treated in parallel with 30 mg/kg b.w. was utilized for a microbiological semiquantitative assay. All litters contained some fetuses showing no detectable TBM accumulation in either kidney or in placentae: at 30 mg/kg/b.w. accumulation appeared more prevalent in placenta than in the kidneys of the corresponding fetuses, as confirmed also by the semiquantitative assay. Some newborns (about 6%) of both groups showed detectable renal TBM residues on the 6th and on the 11th day after the end of treatment. The frequency of newborns showing residues was not obviously related to the dose or the day of sampling, and the concentrations of TBM found were comparable to those observed in fetuses. It is possible that they represent a particularly sensitive subgroup.
Ferrini
A M
AM
Laboratorio Alimenti, Istituto Superiore di Sanità, Roma, Italy.
Aureli
P
P
Ricciardi
C
C
Stazi
A V
AV
Macrì
C
C
Mantovani
A
A
D000818:Animals; D000831:Animals, Newborn; D001681:Biological Assay; D005260:Female; D005333:Fetus / Q000378:metabolism; D007668:Kidney / Q000196:embryology / Q000378:metabolism*; D008297:Male; D008431:Maternal-Fetal Exchange; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats; D017207:Rats, Sprague-Dawley; D014031:Tobramycin / Q000493:pharmacokinetics*
D014031:Tobramycin