title: Immunohistochemical localization of protease-activated receptors in cerebral and testicular arterioles of rats: their dependence on arteriole size and organ-specificity.
abstract: Protease-activated receptors (PARs) expressed in the endothelia and smooth muscles of vessels may play important roles in blood vessel function. Using intracellular calcium ion concentration ([Ca2+]i) imaging, we recently observed that small - but not large - arterioles of the brain responded to proteases, while testicular arterioles showed no response. The purpose of the present study was to examine the heterogeneity of the localization of PARs in arterioles using immunohistochemistry. Consistent with the [Ca2+]i imaging results, neither the thrombin receptor nor PAR2 were evident in large arterioles of the brain. However, the small arterioles of the brain, vascular smooth muscles, and endothelia showed a distinct immunoreactivity against the thrombin receptor and PAR2. The immunoreactivity of PARs in testicular arterioles was faint. In conclusion, size-dependent and/or organ-specific responses of arterioles to proteases are due to the heterogeneous localization of PARs.
authors.affiliation: Departments of Anatomy (Cell Biology Division), Iwate Medical University, Morioka, Japan.
authors.forename: Toshinari
authors.initials: T
authors.lastname: Misaki
authors.forename: Yoh-Ichi
authors.initials: Y
authors.lastname: Satoh
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Saino
authors.forename: Takashi
authors.initials: T
authors.lastname: Kuroda
authors.forename: Kazuki
authors.initials: K
authors.lastname: Masu
authors.forename: D A
authors.initials: DA
authors.lastname: Russa
authors.forename: Akira
authors.initials: A
authors.lastname: Ogawa
mesh_terms: D000818:Animals; D001160:Arterioles / Q000378:metabolism / Q000648:ultrastructure; D002118:Calcium / Q000378:metabolism; D002540:Cerebral Cortex / Q000098:blood supply* / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000378:metabolism; D009928:Organ Specificity; D051381:Rats; D017208:Rats, Wistar; D044462:Receptors, Proteinase-Activated / Q000032:analysis* / Q000378:metabolism; D013737:Testis / Q000098:blood supply* / Q000378:metabolism
chemical_list: D044462:Receptors, Proteinase-Activated; D002118:Calcium