Alteration of strial capillary transport in kanamycin-treated guinea pigs

Effects of chronic administration of kanamycin on the basement membrane anionic sites in the crista ampullaris of guinea pigs

The authors investigated the effects of chronic kanamycin (KM) administration on the basement membrane (BM) anionic sites in the ampulla by studying the binding of cationic polyethyleneimine (PEI). KM sulfate was administered intramuscularly to guinea pigs with normal Preyer's reflexes daily for 10 or 17 days. The PEI distribution was unchanged on the subepithelial BM in the dark cell region and on the capillary BM in the crista ampullaris. However, PEI binding decreased significantly on the subepithelial BM in the sensory cell and transitional cell regions of those guinea pigs administered KM for 17 days. In the sensory cell region, the PEI distribution did not recover until 6 weeks after KM treatment. Findings suggest that chronic administration of KM severely alters the number of subepithelial BM anionic sites in the sensory cell region.

Influence of chronic kanamycin administration on basement membrane anionic sites in the labyrinth

We studied the effect of chronic treatment with kanamycin on the basement membrane (BM) anionic sites in the cochlea and endolymphatic sac using polyethyleneimine (PEI) as a cationic tracer. Albino guinea pigs weighing 250-300 g received kanamycin (400 mg/kg/day, i.m.) for 10 or 17 consecutive days. The number of BM anionic sites as derived from the PEI area was not affected in Reissner's membrane, spiral prominence, basilar membrane or endolymphatic sac, whereas it was significantly decreased in the stria vascularis and spiral limbus, being more marked in the guinea pigs treated for 17 days than in those treated for 10 days. The number of BM anionic sites in these regions did not recover until 6 weeks after kanamycin treatment. These findings suggest that chronically administered kanamycin may selectively and progressively affect the BM anionic sites in the stria vascularis and spiral limbus, resulting in disruption of a barrier function in the cochlea, and that severely impaired BM anionic sites in the cochlea may not recover.

Effect of cisplatin on the negative charge barrier in strial vessels of the guinea pig. A transmission electron microscopic study using polyethyleneimine molecules

The anionic sites on the basement membrane in the cochlea are believed to act as a charge barrier. Using polyethyleneimine (PEI) as a cationic tracer, we examined the effects of cisplatin (CDDP) on anionic sites in the basement membrane in the cochlea. Eight Hartley-strain guinea pigs were separated into control (buffer administration) and CDDP groups. Ultrathin sections of the basal and third turns of the cochlear ducts were examined using a transmission electron microscope. A marked decrease of PEI distribution was noted in the strial vessels of the CDDP group compared to the control group. However, the two groups showed no significant differences in PEI particles on the basement membranes in the basilar and Reissner's membranes, or in the basal and third turns. These findings suggest that the charge barrier in the stria vascularis may be easily injured by the administration of CDDP.