Vasopeptidase-activated latent ligands of the histamine receptor-1.
Int Immunopharmacol
; 17(3): 677-83, 2013 Nov.
Article
en En
| MEDLINE
| ID: mdl-24016859
ABSTRACT
Whether peptidases present in vascular cells can activate prodrugs active on vascular cells has been tested with 2 potential latent ligands of the histamine H1 receptor (H1R). First, a peptide consisting of the antihistamine cetirizine (CTZ) condensed at the N-terminus of ε-aminocaproyl-bradykinin (εACA-BK) was evaluated for an antihistamine activity that could be revealed by degradation of the peptide part of the molecule. CTZ-εACA-BK had a submicromolar affinity for the BK B2 receptor (B2R; IC50 of 590 nM, [(3)H]BK binding competition), but a non-negligible affinity for the human H1 receptor (H1R; IC50 of 11 µM for [(3)H]pyrilamine binding). In the human isolated umbilical vein, a system where both endogenous B2R and H1R mediate strong contractions, CTZ-εACA-BK exerted mild antagonist effects on histamine-induced contraction that were not modified by omapatrilat or by a B2R antagonist that prevents endocytosis of the BK conjugate. Cells expressing recombinant ACE or B2R incubated with CTZ-εACA-BK did not release a competitor of [(3)H]pyrilamine binding to H1Rs. Thus, there is no evidence that CTZ-εACA-BK can release free cetirizine in biological environments. The second prodrug was a blocked agonist, L-alanyl-histamine, potentially activated by aminopeptidase N (APN). This compound did not compete for [(3)H]pyrilamine binding to H1Rs. The human umbilical vein contractility assay responded to L-alanyl-histamine (EC50 54.7 µM), but the APN inhibitor amastatin massively (17-fold) reduced its apparent potency. Amastatin did not influence the potency of histamine as a contractile agent. One of the 2 tested latent H1R ligands, L-alanyl-histamine, supported the feasibility of pro-drug activation by vascular ectopeptidases.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Péptido Hidrolasas
/
Péptidos
/
Receptores Histamínicos H1
/
Profármacos
/
Receptor de Bradiquinina B2
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Int Immunopharmacol
Asunto de la revista:
ALERGIA E IMUNOLOGIA
/
FARMACOLOGIA
Año:
2013
Tipo del documento:
Article
País de afiliación:
Estados Unidos