Local substances regulating cochlear blood flow.
The regulation of cochlear lateral wall blood flow was investigated in rats using histochemistry, immunohistochemistry and transmission electron microscopy. The contractile protein, tropomyosin (TM) was localized in the pericyte around the vessels of spiral ligament but little was seen around strial capillaries. Prostaglandin I2 (PGI2) is a vasodilatory substance produced by PGI2 synthase (PGI2S), which is present in the endothelium of the vessels of spiral ligament but not much is present around strial capillaries. Endothelial nitric oxide synthase (eNOS) was present in the endothelium of both the vessels of spiral ligament and strial capillaries. These findings indicate that the blood flow of the cochlear lateral wall is regulated mainly in the spiral ligament by locally produced substances and that strial blood flow is not significantly regulated by pericytes responsible for enlargement or constriction of capillaries.
Konishi
K
K
Department of Otolaryngology, Osaka City University Medical School, Japan.
Yamane
H
H
Iguchi
H
H
Takayama
M
M
Nakagawa
T
T
Sunami
K
K
Nakai
Y
Y
D000818:Animals; D002196:Capillaries / Q000737:chemistry; D003051:Cochlea / Q000098:blood supply* / Q000737:chemistry / Q000648:ultrastructure; D003577:Cytochrome P-450 Enzyme System / Q000032:analysis; D006651:Histocytochemistry; D007150:Immunohistochemistry; D019746:Intramolecular Oxidoreductases / Q000032:analysis; D008854:Microscopy, Electron; D016253:Microscopy, Immunoelectron; D009252:NADPH Dehydrogenase / Q000032:analysis; D019001:Nitric Oxide Synthase / Q000032:analysis; D052250:Nitric Oxide Synthase Type III; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow / Q000502:physiology; D014335:Tropomyosin / Q000032:analysis
D014335:Tropomyosin; D003577:Cytochrome P-450 Enzyme System; D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D009252:NADPH Dehydrogenase; D019746:Intramolecular Oxidoreductases; C022461:prostacyclin synthetase