Systemic treatment with Mycobacterium bovis bacillus Calmette-Guérin (BCG) potentiates kinin B1 receptor agonist-induced nociception and oedema formation in the formalin test in mice.
This study investigates the effect and some of the mechanisms involved following systemic treatment of mice with Mycobacterium bovis bacillus Calmette-Guérin (BCG) (1 dose per animal containing 6.4 x 10(4) colony-forming units (CFu) 20-60 days beforehand) on modulation of the kinin B1 receptor agonist-induced nociception and oedema formation in the formalin test. Intraplantar (i.p.l.) co-injection of des-Arg9-bradykinin (4-32 nmol/paw) or des-Arg10-kallidin (1-15 nmol/paw), together with sub-maximal concentrations of formalin (0.01 or 0.5%), potentiated (P < 0.01) both pain phases and the paw oedema caused by formalin in animals pre-treated with saline. However, when animals were pre-treated with BCG, the dose-response curves for both B1 agonists were shifted 2 to 8-fold to the left. These B1-mediated effects peaked at 30-45 days after BCG treatment and were still elevated at 60 days after BCG injection. The pain response and oedema formation caused by i.p.l. co-injection of des-Arg9-bradykinin, together with formalin in BCG-pre-treated animals, were dose-dependently antagonised by i.p.l. co-injection of the B1 antagonist des-Arg9[Leu8]bradykinin (1-15 nmol/paw), but were not affected by the B2 antagonist Hoe 140 (10 nmol/paw). The i.p.l. co-injection of tyrosine8-bradykinin (a B2 agonist, 3-15 nmol/paw) with formalin (0.01 or 0.5%) potentiated the pain response and paw oedema in BCG and saline-pre-treated animals to the same extent (P < 0.01). The actions caused by tyrosine8-bradykinin were antagonised by Hoe 140, while des- Arg9[Leu8]bradykinin (10 nmol/paw) had no effect. Dexamethasone (0.5 mg/kg, s.c.), given every 24 h, from day 0 to 30-45, inhibited significantly the potentiation of nociceptive response and oedema formation caused by i.p.l. co-injection of formalin plus des-Arg9-bradykinin, while indomethacin (2 mg/kg, i.p.) or phenidone (30 mg/kg, i.p.), given 1 h prior, caused less inhibition. These data show that the long-term systemic treatment of mice with BCG produced dose-related potentiation of B1 receptor agonist-mediated nociception and oedema formation, without affecting similar responses caused by the B2 receptor agonist tyrosine8-bradykinin. Thus, systemic treatment of mice with BCG induces upregulation of B1 receptors, without affecting B2-mediated responses, by a mechanism that seems to be secondary to cytokine release.
de Campos
R O
RO
Department of Pharmacology, Center of Biological Sciences, Universidade Federal de Santa Catarina, Florianópolis, Brazil.
Henriques
M G
MG
Calixto
J B
JB
D000818:Animals; D001920:Bradykinin / Q000031:analogs & derivatives / Q000494:pharmacology; D003907:Dexamethasone / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004487:Edema / Q000139:chemically induced / Q000503:physiopathology*; D005557:Formaldehyde / Q000494:pharmacology; D006614:Hindlimb; D007213:Indomethacin / Q000494:pharmacology; D007609:Kallidin / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D051379:Mice; D009163:Mycobacterium bovis / Q000276:immunology*; D010146:Pain / Q000139:chemically induced / Q000503:physiopathology*; D010147:Pain Measurement / Q000187:drug effects; D011720:Pyrazoles / Q000494:pharmacology; D043783:Receptor, Bradykinin B1; D018002:Receptors, Bradykinin / Q000819:agonists / Q000502:physiology*
D011720:Pyrazoles; D043783:Receptor, Bradykinin B1; D018002:Receptors, Bradykinin; C026201:bradykinin, Tyr-; C024626:bradykinin, des-Arg(9)-; D005557:Formaldehyde; D007609:Kallidin; C051090:bradykinin, Leu(8)-des-Arg(9)-; C052787:kallidin, des-Arg(10)-; C065679:icatibant; D003907:Dexamethasone; C015429:phenidone; D001920:Bradykinin; D007213:Indomethacin