Capsaicin-induced release of VIP-like immunoreactivity: modulation by enzyme inhibitors.
Am J Physiol
; 271(4 Pt 1): L506-11, 1996 Oct.
Article
em En
| MEDLINE
| ID: mdl-8897896
Vasoactive intestinal peptide (VIP) is a potent bronchial smooth muscle relaxant. In the present study we measured the release of VIP-like immunoreactivity (VIP-LI) after tracheal infusion of capsaicin, histamine, and methacholine in isolated guinea pig lungs superfused through the trachea. We also studied if inhibition of VIP enzymatic cleavage using a combination of an inhibitor of neutral endopeptidase [thiorphan (Thio)] and an inhibitor of serine proteases [soybean trypsin inhibitor (STI)] influenced the airway effects of capsaicin. Infusion of capsaicin resulted in a significant increase in VIP-LI in the perfusate (12.32 +/- 4.80 to 33.52 +/- 8.46 fmol/5 min fraction; P < 0.001). There was no increase in VIP-LI after infusion of methacholine or histamine. Maximal changes in airway opening pressure (Pao) observed 0-10 min after tracheal infusion of capsaicin were significantly greater in the Thio group than the control group and the groups of lungs that received STI or STI + Thio (P < 0.005). In addition, recovery of VIP-LI in the superfusate after infusion of capsaicin was significantly greater in the group of lungs that was superfused with Thio + STI compared with STI, Thio, and control groups. Our results suggest that a bronchodilator peptide with the profile of enzymatic cleavage of VIP also modulates capsaicin effects, since the increase in Pao in the presence of Thio + STI was significantly lower than Thio alone.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Peptídeo Intestinal Vasoativo
/
Capsaicina
/
Fibras Nervosas
/
Neurotoxinas
Limite:
Animals
Idioma:
En
Revista:
Am J Physiol
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos