Neuropeptides, including substance P (SP) may play a role in neurogenic inflammation. Although SP‐immunoreactive (SP‐IR) axons are known to be present within the oral mucosa (OM) and salivary glands, the functional significance of SP in oral mucosa and sublingual salivary gland (SLG) is not fully understood. The present experiments were carried out to study the effects of SP infused into the left common carotid artery on vascular permeability in the OM and in the SLG of male rats. Vascular permeability was assessed on the basis of Evans Blue extravasation. Separate groups of animals received histamine (H1) receptor antagonist (chloropyramine, 10 mg kg−1 i.v.) or prostaglandin synthesis inhibitor (indomethacin, 4 mg kg−1 i.v.) prior to SP infusions. Infusion of SP in doses of 30 and 74 pmol min−1 increased the vascular permeability of OM by 162.3±16.3% (n=8, p>0.05) and 482.7±46.7% (n=8, p>0.001), respectively. SP in a dose of 15 pmol min−1 did not increase Evans Blue extravasation in OM (38.3±4.0 μ g−1, n=8, compared to the control: 44.0±7.9 μg g−1, n = 8, NS). Although SP increased plasma extravasation in OM, it failed to affect vascular permeability in SLG (15 pmol min−1 SP: 46.9±6.9 μg g–1, n = 6, NS; 30 pmol min−1 SP: 54.1 ±6.2 μg g−1, n= 11 NS; 74 pmol min−1 SP: 49.7±2.3 μg g−1, n = 7, NS; compared to the control: 48.9±5.8 μg g−1, n = 8). After chloropyramine administration the SP effect on vascular permeability decreased in OM by 41.5±5.9% (n=10, p>0.05). Indomethacin pretreatment similarly diminished the effect of SP on the dye extravasation in OM by 43.9±6.1% (n = 8, p>0.01). Our results suggest that the effect of SP on plasma extravasation in the oral mucosa is partly elicited via the release of vasoactive agents (histamine, prostaglandins), and the microvasculature of SLG has lower sensitivity of SP than that of the oral mucosa.
|Number of pages||5|
|Journal||Journal of Periodontal Research|
|Publication status||Published - máj. 1995|
ASJC Scopus subject areas