TY - JOUR
T1 - Uptake of Gentamicin by Bullfrog Saccular Hair Cells in vitro
AU - Steyger, P. S.
AU - Peters, S. L.
AU - Rehling, J.
AU - Hordichok, A.
AU - Dai, C. F.
PY - 2003/12
Y1 - 2003/12
N2 - Vertebrate sensory hair cells in the inner ear are pharmacologically sensitive to aminoglycoside antibiotics. Although the ototoxicity, of aminoglycosides is well known, the route of drug uptake by hair cells and mechanisms of cytotoxicity remain poorly understood. Previously published studies have documented the intracellular distribution of gentamicin using immunocytochemical, electron microscopic, and autoradiographic methods. In this article, we compare the subcellular distribution of fluorescently conjugated gentamicin (gentamicin-Texas Red, GTTR) with immunolabeled gentamicin using confocal or electron microscopy. Gentamicin (detected by post-fixation immunocytochemistry) and GTTR were rapidly taken up by hair cells throughout the bullfrog saccular explant in vitro and preferentially in peripheral hair cells. Immunolabeled gentamicin and GTTR were observed at the apical membranes of hair cells, particularly in their hair bundles. GTTR was also identified within a variety of subcellular compartments within hair cells, including lysosomes, mitochondria, Golgi bodies, endoplasmic reticulum, and nuclei, and in similar structures by immunoelectron microscopy. The distributions of GTTR and immunolabeled gentamicin are largely identical and corroborate a variety of published immunocytochemical and autoradiography studies. Thus, GTTR is a valid fluorescent probe with which to investigate the pharmacokinetics and mechanisms of gentamicin accumulation.
AB - Vertebrate sensory hair cells in the inner ear are pharmacologically sensitive to aminoglycoside antibiotics. Although the ototoxicity, of aminoglycosides is well known, the route of drug uptake by hair cells and mechanisms of cytotoxicity remain poorly understood. Previously published studies have documented the intracellular distribution of gentamicin using immunocytochemical, electron microscopic, and autoradiographic methods. In this article, we compare the subcellular distribution of fluorescently conjugated gentamicin (gentamicin-Texas Red, GTTR) with immunolabeled gentamicin using confocal or electron microscopy. Gentamicin (detected by post-fixation immunocytochemistry) and GTTR were rapidly taken up by hair cells throughout the bullfrog saccular explant in vitro and preferentially in peripheral hair cells. Immunolabeled gentamicin and GTTR were observed at the apical membranes of hair cells, particularly in their hair bundles. GTTR was also identified within a variety of subcellular compartments within hair cells, including lysosomes, mitochondria, Golgi bodies, endoplasmic reticulum, and nuclei, and in similar structures by immunoelectron microscopy. The distributions of GTTR and immunolabeled gentamicin are largely identical and corroborate a variety of published immunocytochemical and autoradiography studies. Thus, GTTR is a valid fluorescent probe with which to investigate the pharmacokinetics and mechanisms of gentamicin accumulation.
KW - Drug accumulation
KW - Endocytosis
KW - Gentamicin
KW - Hair cells
KW - Ototoxicity
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U2 - 10.1007/s10162-003-4002-5
DO - 10.1007/s10162-003-4002-5
M3 - Article
C2 - 14605921
AN - SCOPUS:1642579619
SN - 1525-3961
VL - 4
SP - 565
EP - 578
JO - JARO - Journal of the Association for Research in Otolaryngology
JF - JARO - Journal of the Association for Research in Otolaryngology
IS - 4
ER -