In:
Ophthalmologica, S. Karger AG, Vol. 215, No. 4 ( 2001), p. 303-308
Abstract:
〈 i 〉 Purpose: 〈 /i 〉 To clarify the effect of bradykinin on cytosolic free calcium mobilization and cell proliferation in cultured bovine corneal endothelial cells (BCEC). 〈 i 〉 Methods: 〈 /i 〉 The cytosolic free calcium concentration (Ca 〈 sup 〉 2+ 〈 /sup 〉 ] 〈 sub 〉 i 〈 /sub 〉 ) was measured with the InCa 〈 sup 〉 TM 〈 /sup 〉 Imaging System after the treatment of bradykinin (10 〈 sup 〉 –11 〈 /sup 〉 to 10 〈 sup 〉 –7 〈 /sup 〉 〈 i 〉 M 〈 /i 〉 ) alone or with the pretreatments of EGTA, bradykinin receptor (Bk 〈 sub 〉 1 〈 /sub 〉 and Bk 〈 sub 〉 2 〈 /sub 〉 ) antagonists and an inhibition of phospholipase C (U-73122). Also, the effect of bradykinin on cell proliferation in BCEC was evaluated using cell counts. 〈 i 〉 Results: 〈 /i 〉 In BCEC, [Ca 〈 sup 〉 2+ 〈 /sup 〉 ] 〈 sub 〉 i 〈 /sub 〉 in the resting state was 87 ± 9 n 〈 i 〉 M 〈 /i 〉 . Bradykinin induced an increment of [Ca 〈 sup 〉 2+ 〈 /sup 〉 ] 〈 sub 〉 i 〈 /sub 〉 in a concentration-dependent manner and its 50% effective concentration was approximately 5 × 10 〈 sup 〉 –11 〈 /sup 〉 〈 i 〉 M 〈 /i 〉 . A [Ca 〈 sup 〉 2+ 〈 /sup 〉 ] 〈 sub 〉 i 〈 /sub 〉 increment at 10 〈 sup 〉 –8 〈 /sup 〉 〈 i 〉 M 〈 /i 〉 bradykinin was inhibited with the pretreatment of EGTA, an extracellular calcium chelator. U-73122 (5 × 10 〈 sup 〉 –6 〈 /sup 〉 〈 i 〉 M 〈 /i 〉 ) attenuated the bradykinin-induced [Ca 〈 sup 〉 2+ 〈 /sup 〉 ] 〈 sub 〉 i 〈 /sub 〉 increment. The pretreatment of HOE-140 (Bk 〈 sub 〉 2 〈 /sub 〉 antagonist) almost attenuated the bradykinin (10 〈 sup 〉 –8 〈 /sup 〉 〈 i 〉 M 〈 /i 〉 )-induced [Ca 〈 sup 〉 2+ 〈 /sup 〉 ] 〈 sub 〉 i 〈 /sub 〉 increase, but des-Arg 〈 sup 〉 9 〈 /sup 〉 -[Leu 〈 sup 〉 8 〈 /sup 〉 ]-bradykinin (Bk 〈 sub 〉 1 〈 /sub 〉 antagonist) did not suppress it. To investigate the physiological effect of bradykinin, the effect of bradykinin on cell proliferation was studied. 10 〈 sup 〉 –8 〈 /sup 〉 〈 i 〉 M 〈 /i 〉 of bradykinin produced a significant increase in cell numbers. This mitogenic effect of bradykinin was inhibited by the Bk 〈 sub 〉 2 〈 /sub 〉 antagonist. 〈 i 〉 Conclusions: 〈 /i 〉 Bradykinin-induced stimulation of the signal transduction pathway in BCEC is coupled with the Bk 〈 sub 〉 2 〈 /sub 〉 type receptor. Furthermore, bradykinin produces the mitogenic effect in BCEC.
Type of Medium:
Online Resource
ISSN:
0030-3755
,
1423-0267
Language:
English
Publisher:
S. Karger AG
Publication Date:
2001
detail.hit.zdb_id:
1483531-9
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