Tissue distribution of gentamicin in lambs: effect of postnatal age and acute hypoxemia

Gentamicin tissue distribution and uptake were studied in chronically catheterized lambs in relation to their possible role in postnatal age- and hypoxemia-related effects on serum gentamicin concentration. Gentamicin serum concentration (SGent) was proportional to dose and was paralleled by gentamicin delivery to specific organ tissues (DGent) and tissue gentamicin content (TGent). SGent per dose was higher in older lambs (2-5 weeks of age) and in hypoxemic (pO2 36 +/- 7 Torr) lambs. DGent to liver, heart and adrenal tissues per unit dose was increased in response to hypoxemia. TGent paralleled SGent under these conditions. Hypoxemia- and age-related effects on SGent were not explained by differences in TGent in these lambs.