Artículos de revistas
Activation of central α(2)-adrenoceptors mediates salivary gland vasoconstriction
Fecha
2013Registro en:
Archives of Oral Biology, Oxford, v.58, p.168-173, 2013
10.1016/j.archoralbio.2012.06.017
Autor
Moreira, Thiago dos Santos
Takakura, Ana Carolina Thomaz
Menani, José V.
Colombari, Eduardo
Institución
Resumen
OBJECTIVE:
Peripheral treatment with the cholinergic agonist pilocarpine increases salivary gland blood flow and induces intense salivation that is reduced by the central injection of moxonidine (α(2)-adrenoceptors/imidazoline agonist). In the present study, we investigated the effects of the intracerebroventricular (i.c.v.) injection of pilocarpine alone or combined with moxonidine also injected i.c.v. On submandibular/sublingual gland (SSG) vascular resistance. In addition, the effects of these treatments on arterial pressure, heart rate and on mesenteric and hindlimb vascular resistance were also tested.
DESIGN:
Male Holtzman rats with stainless steel cannula implanted into lateral ventricle and anaesthetized with urethane+α-chloralose were used.
RESULTS:
Pilocarpine (500nmol/1μl) injected i.c.v. Reduced SSG vascular resistance and increased arterial pressure, heart rate and mesenteric vascular resistance. Contrary to pilocarpine alone, the combination of moxonidine (20nmol/1μl) and pilocarpine injected i.c.v. Increased SSG vascular resistance, an effect abolished by the pre-treatment with the α(2)-adrenoceptor antagonist yohimbine (320nmol/2μl). The increase in arterial pressure, heart rate and mesenteric resistance was not modified by the combination of moxonidine and pilocarpine i.c.v.
CONCLUSION:
These results suggest that the activation of central α(2)-adrenoceptors may oppose to the effects of central cholinergic receptor activation in the SSG vascular resistance.