Effects of keratin on bone resorption in experimental otitis media.
Keratin debris is a constant feature in middle-ear cholesteatoma. Keratin prepared from rat skin induced a foreign-body granuloma in the subcutaneous space in the rat. In vitro this granuloma produced high levels of bone-resorbing factors: prostaglandin E2, osteoclast-activating factor, and leucine aminopeptidase. In the in vivo study, keratin-induced granuloma in the rat middle ear caused partial resorption of the cochlear wall. Macrophages, fibroblasts, and osteoclastlike cells were found at bone-resorption areas. These cells appeared to be responsible for bone resorption through production of prostaglandin E2, osteoclast-activating factor, and proteases.
D000818:Animals; D001862:Bone Resorption / Q000187:drug effects; D002351:Carrageenan / Q000494:pharmacology; D002781:Cholesteatoma / Q000139:chemically induced / Q000378:metabolism*; D015232:Dinoprostone; D066298:In Vitro Techniques; D007633:Keratins / Q000378:metabolism*; D007931:Leucyl Aminopeptidase / Q000378:metabolism; D008222:Lymphokines / Q000378:metabolism; D008297:Male; D010033:Otitis Media / Q000378:metabolism*; D011458:Prostaglandins E / Q000378:metabolism; D051381:Rats
D008222:Lymphokines; D011458:Prostaglandins E; C008718:osteoclast activating factor; D007633:Keratins; D002351:Carrageenan; D007931:Leucyl Aminopeptidase; D015232:Dinoprostone