Response of cochlear blood flow to prostaglandin E1 applied topically to the round window.
CONCLUSIONS
The increase in cochlear blood flow (CBF) after administration of prostaglandin E1 (PGE1) to the round window depends on increased blood flow through the anterior inferior cerebellar artery (AICA).


OBJECTIVE
To evaluate the response of CBF to PGE1 applied topically to the round window, and to investigate the origin of blood flow changes after this topical application.


METHODS
The response of CBF to topically applied PGE1 was measured by placing the tip of a laser Doppler probe on the bony wall of the basal turn of the cochlea after the middle ear mucosa over the cochlea had been removed in guinea pigs and rats. In rats, the CBF response to PGE1 administration was investigated after occlusion of the AICA or stapedial artery.


RESULTS
CBF increased following PGE1 administration in both guinea pigs and rats. In rats, CBF increased from 100% to 132%+/-10% (mean+/-SD) after the topical application of 0.5 microl of a 0.014% PGE1 solution. CBF decreased after occlusion of the AICA or stapedial artery but did not increase after PGE1 administration during occlusion of the AICA. The CBF response to PGE1 administration was similar before and after occlusion of the stapedial artery.
Tominaga
Mitsuo
M
Department of Otorhinolaryngology, Nagoya University School of Medicine, Nagoya, Japan.
Yamamoto
Hiroshi
H
Sone
Michihiko
M
Teranishi
Masa-aki
MA
Nakashima
Tsutomu
T
D000287:Administration, Topical; D000527:Alprostadil / Q000494:pharmacology*; D000818:Animals; D003051:Cochlea / Q000098:blood supply*; D015834:Cochlear Diseases / Q000188:drug therapy; D004195:Disease Models, Animal; D006168:Guinea Pigs; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow / Q000187:drug effects; D012405:Round Window, Ear / Q000187:drug effects*; D012680:Sensitivity and Specificity
D000527:Alprostadil