A possible alternative mechanism of kinin generation in vivo by cathepsin L

Date
2005-07-01Author
Puzer, L.
Vercesi, J.
Alves, MFM
Barros, NMT
Araujo, M. S.
Juliano, M. A.
Reis, M. L.
Juliano, L.
Carmona, A. K.
Type
ArtigoISSN
1431-6730Is part of
Biological ChemistryDOI
10.1515/BC.2005.081Metadata
Show full item recordAbstract
We investigated the ability of cathepsin L to induce a hypotensive effect after intravenous injection in rats and correlated this decrease in blood pressure with kinin generation. Simultaneously with blood pressure decrease, we detected plasma kininogen depletion in the treated rats. the effect observed in vivo was abolished by preincubation of cathepsin L with the cysteine peptidase-specific inhibitor E-64 (11 mu m) or by previous administration of the bradykinin B-2 receptor antagonist JE049 (4 mg/kg). A potentiation of the hypotensive effect caused by cathepsin L was observed by previous administration of the angiotensin I-converting enzyme inhibitor captopril (5 mg/kg). in vitro studies indicated that cathepsin L excised bradykinin from the synthetic fluorogenic peptide Abz-MTSVIRRPPGFSPFRAPRV-NH2, based on the Met(375)-Val(393) sequence of rat kininogen (Abz=o-aminobenzoic acid). in conclusion, our data indicate that in vivo cathepsin L releases a kinin-related peptide, and in vitro experiments suggest that the kinin generated is bradykinin. Although it is well known that cysteine proteases are strongly inhibited by kininogen, cathepsin L could represent an alternative pathway for kinin production in pathological processes.
Citation
Biological Chemistry. Berlin: Walter de Gruyter & Co, v. 386, n. 7, p. 699-704, 2005.Collections
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