Observation About The Preventative Effect Of Hyperbaric Oxygen(HBO) On Gentamicini (GM) Cochlear Toxicity In Guinea Pigs

[Objective] To study the protection of hyperbaric oxygen to gentamicini toxic deafness induction and its clinical significance by researching 36 guinea pig modles. [Method] Thirty-six Guinea pigs as animal modles were studied. The animals were randomly divided into hyperbaric oxygen(HBO)+ gentamicini(GM) group, hyperbaric air (HBA)+GM group, GM group and the normal solution (NS) group. The HBO+GM group> HBA+GM group:Guinea pigs were imdiatly injected with gentamicin to their abdominal cavity after had been inhaled the hyperbaric oxygen and hyperbaric air 2ATA (atmosphere absolute)for 60 minutes respectively. The dosage was 150mg/kg, one time each day, for 5 days. The GM group were injected with GM only at the same dosage. NS group were injected with 4. 5ml NS only. The andictive brain response(ABR)were measured before injection and exposure. 6th experimental day respectively, and the pathology changes of cochlear hair cells were observed. [Result]The threshold shift(dB) (x盨X) of guinea pigs exposured to HBO beforehand was 1. 875+0.9127, and the difference had significant meaning compared with that of the HBC+GM group (19.6429+.1.9233)(P<0.01) and GM group (21. 7857+.1. 6246) ( PO.05) respectively. Compared with the NS group, the threshold shift difference had no significant meaning(P>0. 05). The difference of threshold shift between HBC+GM 'group and GM group had no significant meaning (PX).05) .Compared with the NS group, the threshold shift difference of HBC+GM and GM groups all had significant meaning(P<0. 01). But the threshold value of the NS group had no obvious changing. Scanning election microscope of cochlear hair cells showed that the main damage was in bottom and second turns after 5 days' GM injection. Many outer hair cells became scattering lodging and conglutinated to fusion glomeration. The damage to the inner hair cells was light, the swelling, degeneration, scattering abscission in many inner hair cells was observed. The third and forth turns were damaged lightly. The swelling, degeneration can be observed. The damage to the HBC+GM group was almost simillar compared with that of GM group. But only swelling, degeneration could been observed in HBO+GM group. [Conlusion]The beforehand exposure of HBO has obvious protection againstthe auditory functional and structural damage of cochlear hair cells caused by Gentamicin in guinea pigs at short terms. The long-term influence and complex protection and central need further study.