[Preliminary study on inner ear ischemic model induced by ferromagnetic embolism].
OBJECTIVE
To set up an inner ear ischemic model in guinea pig with ferromagnetic embolism.


METHODS
A magnet was fitted in the external auditory canal and carbonyl iron filings (1%, 1 ml/kg) was injected into jugular, then the inner ear vessels were obstructed by ferromagnetic spheres. Cochlear blood flow (CBF) and number of red blood cells in the stria vessels were used to detect the model's ischemia of cochleae. The slice of temple bone and basal membrane stained by silver nitrate were used for inner ear's histopathological observations.


RESULTS
The iron spheres were amassed in the one and two-day-later's model of inner ear vessels, which resulted in embolism. The number of red blood cells in the stria vessels decreased and then recovered to normal level after 4 days, but the CBF decreased to 50% +/- 10% of basic level immediately and recovered to 99% +/- 41% 4 days later. Scattered lesion of out hair cell cilium could be seen in cochleae in eight-day-later's model, and degenerations in different degree were found in vascular stria.


CONCLUSIONS
The methods of inner ear ischemic model with ferromagnetic embolism could be practical and the decrease of CBF was reversible, so it may be an ideal model for studying some ischemic inner ear diseases and evaluating the effects of therapeutic drugs.
Li
Hongtao
H
Department of Otorhinolaryngology, Head and Neck Surgery, Daping Hospital, Third Military Medical University, Chongqing 400042, China. chenxm@mail.tmmu.com.cn
Zhou
Dingrong
D
D000818:Animals; D004195:Disease Models, Animal; D007758:Ear, Inner / Q000098:blood supply*; D004617:Embolism; D005260:Female; D006168:Guinea Pigs; D007511:Ischemia; D008280:Magnetics; D008297:Male; D008863:Microspheres; D012039:Regional Blood Flow