The pH-dependent influence of aminoglycoside antibiotics on iodohippurate accumulation in rabbit renal cortical slices.
The effects of aminoglycoside antibiotics on 125I-hippurate (OIH) accumulation in rabbit renal cortical slices were assessed in vitro using incubation media with pH-values ranging from 6.4 to 8.4 and containing streptomycin, kanamycin, amikacin, gentamicin and tobramycin in concentrations ranging from 100 to 2,000 microgram base/ml. The aminoglycoside-induced inhibition of OIH accumulation was clearly pH-dependent and most pronounced at alkaline pH-values. At pH 6.4 and 7.4 the aminoglycosides had either no or only moderate effects on OIH accumulation, while all drugs produced a distinct depression in accumulation at pH 7.9 and 8.4. The microbiologically inert N-acetyl gentamicin had no influence on accumulation. The influence of aminoglycosides on OIH accumulation is probably related to the pKa-values of these drugs and implies the presence of free amino groups.
D000583:Amikacin / Q000494:pharmacology; D000617:Aminoglycosides / Q000494:pharmacology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D005839:Gentamicins / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007465:Iodohippuric Acid / Q000378:metabolism*; D007612:Kanamycin / Q000494:pharmacology; D007672:Kidney Cortex / Q000187:drug effects / Q000378:metabolism*; D011817:Rabbits; D013307:Streptomycin / Q000494:pharmacology; D014031:Tobramycin / Q000494:pharmacology
D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D005839:Gentamicins; D007465:Iodohippuric Acid; D007612:Kanamycin; D000583:Amikacin; D014031:Tobramycin; D013307:Streptomycin