[The technique of chronic infusion of drugs into the cochlea by an osmotic pump].
OBJECTIVE
To introduce a method of chronic infusion of drugs into the cochlea using a osmotic pump.


METHODS
A stainless steel tube was surgically implanted into the basal turn of the chinchilla cochlea and connected to the pump. To assess the reliability of the procedure, and the pump, Hank's solution or L-buthionine-[S,R]-sulfoximine (BSO) was infused into the cochlea by this pump and inferior colliculus (IC) potential and hair cell morphology were examined.


RESULTS
In three Hank's solution infused cochleas, the thresholds of IC potential were kept in the normal level and no hair cell loss was found 14 days after the beginning of the infusion, suggested that the pump implantation and Hank's solution infusion had no significant effects on the cochlear functions. In contrast, threshold shifts of IC potentials and hair cell loss were found in two BSO infused animals, suggested that the infused solution had distributed into the whole cochlea.


CONCLUSIONS
This study indicates that the osmotic pump can be used in chronic delivery of experimental drugs into the cochlea.
Hu
B
B
Chinese PLA General Hospital, Beijing 100853.
Salvi
R J
RJ
Henderson
D
D
D000818:Animals; D019328:Buthionine Sulfoximine / Q000494:pharmacology; D002682:Chinchilla; D003051:Cochlea / Q000473:pathology / Q000502:physiology; D006198:Hair Cells, Auditory / Q000187:drug effects; D007245:Inferior Colliculi / Q000502:physiology*; D015918:Infusion Pumps, Implantable; D008564:Membrane Potentials; D009997:Osmotic Pressure
D019328:Buthionine Sulfoximine