Am. Genaro et al., Involvement of the endogenous nitric oxide signalling system in bradykininreceptor activation in rat submandibular salivary gland, ARCH ORAL B, 45(9), 2000, pp. 723-729
Biochemical signalling events coupled to the bradykinin Bz-receptor subtype
, related to nitric oxide and prostaglandin E-2 generation were studied in
rat submandibular gland. Bradykinin stimulation of the B-2-receptor trigger
ed activation of phosphoinositide turnover, translocation of protein kinase
C, stimulation of nitric oxide synthase activity, increased production of
cGMP and release of prostaglandin E-2. Bradykinin stimulation of nitric oxi
de synthase and cGMP production was blunted by agents able to interfere wit
h calcium/calmodulin and phospholipase C activities, while a protein kinase
C inhibitor was able to stimulate bradykinin action. Moreover, a specific
B-2-bradykinin antagonist of the reversible nitric oxide synthase inhibitor
abrogated the bradykinin stimulation of nitric oxide synthase activity, cG
MP accumulation and prostaglandin E-2 generation. Furthermore, a specific i
nhibitor of phospholipase A(2) blocked the bradykinin-induced prostaglandin
E-2 release. These results suggest that apart, from the direct effect of b
radykinin as an inducer of vasopermeability, it also appears to be a vasoac
tive chemical mediator that triggers, through release of prostaglandin E-2,
a feedback mechanism that induces a protective adaptation of the gland, mo
dulating the course of inflammation. (C) 2000 Elsevier Science Ltd. All rig
hts reserved.