Uptake and accumulation of gentamicin by mouse hair cells from the cochlear explants in vitro / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the upstaging and accumulation of gentamicin by mouse hair cells in vitro.</p><p><b>METHODS</b>Cochlear explants were prepared from the microdissected neonatal mouse cochlea. Cochlear explants were cultured with gentamicin-Texas-red conjunction (GTTR) for different time. Laser confocal microscopy was used to observe the distribution of GTTR in the cochlear sensory cells after labeling with phalloidin-alexa-488.</p><p><b>RESULTS</b>Soon after culture, there was diffuse red staining all tissue cells in the explants. At later time the hair cells were more staining than other cells in the explants. There was no obviously accumulation of GTTR in the supporting cells. The peak level of fluorescent density was reached at 24 hours culture. The GTTR was seen in the infracuticular zone of the hair cells. There was still accumulation of GTTR in the hair cells of the explants after 7 days culturing.</p><p><b>CONCLUSIONS</b>GTTR and cochlea explants were useful methods to investigate the pharmacokinetics and mechanisms of gentamicin accumulation over time.</p>

Distribution of gentamicin in inner ear after intratympanic gentamicin injection / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate uptake and accumulation of gentamicin by cells in the guinea pig inner ear after intratympanic injection using a fluorescent probe--gentamicin-Texas-red conjunction (GTTR).</p><p><b>METHODS</b>Adult guinea pigs (n = 80) were administered a single dose of GTrR to the middle ear cavity through the intact membrane and survived for 12 h, 24 h, 48 h, 3 d, 4 d, 7 d, 14 d and 28 d. The distribution of GTTR in the cochlear and vestibular cells was observed after staining with phalloidin-alexa-488. Texas Red and DMSO were injected into the tympanum as control.</p><p><b>RESULTS</b>Diffuse staining of gentamicin in the labyrinth was observed initially after local drug administration. At later time point the outer hair cells and sensory cells of vestibular organ were staining more densely than the support cells in the inner ear. The peak level of fluorescent density was reached 3 days after local injection. The GTTR was observed in the infracuticular zone.</p><p><b>CONCLUSIONS</b>GTTR was a potential fluorescent probe to investigate the pharmacokinetics and mechanisms of gentamicin accumulation in local application.</p>