Role of Submandibular Salivary Glands in LPS-Induced Lung Inflammation in Rats

Abstract

Objective: Literature data suggest that rodent salivary glands can exert a neuroimmunomodulatory influence on distant inflammatory events. The release of regulatory factors by salivary glands appears to be influenced by time-dependent factors. In this paper we examined this possibility directly by studying the role of submandibular salivary glands in the temporal profile of lypopolysaccharide (LPS)-induced lung inflammation in rats. Methods: The submandibular glands were removed (SMGx) or not (sham) and, 4 days later, the animals received an intravenous LPS injection (Salmonella abortus equi, 1 mg/kg). Cells in peripheral blood and in bronchoalveolar and bone marrow lavages were quantified after 90 min, 1, 3 and 5 days. Tumor necrosis factor (TNF) activity and corticosterone concentrations in serum were also determined. Baseline values were determined in a group of naïve rats. Results: One day after the LPS injection, neutrophil counts in lungs and blood in both animal groups were elevated, but the SMGx rats presented a significantly lower response in comparison to the sham-operated controls. Five days after LPS treatment, however, SMGx rats had higher neutrophil counts in the lungs than did sham animals, but numbers of blood neutrophils were equal. Ninety minutes after LPS injection, a peak of serum TNF activity was detected in both groups compared with naïve levels. At this time point, TNF activity was about 135% higher in the serum of the SMGx group than in controls. Corticosterone levels of sham-operated controls rose only on the 5th day after LPS, whereas SMGx rats had significant peaks of corticosterone both on the 1st and the 5th day, but not on the 3rd day. Conclusion: Our data indicate that submandibular glands have a dual effect on inflammatory pulmonary response by differentially modulating the profile of lung neutrophil influx.

Effects of Amphetamine on Immune-Mediated Lung Inflammatory Response in Rats

“…Cells were counted under a light microscope in Neubauer chambers. Differential cell count was carried out on the cytocentrifuged (170 g for 3 min) cell suspension (70 Ìl) using standard morphological criteria after staining with Rosenfeld dye [29].…”

“…The total number of cells was counted with the aid of a light microscope in Neubauer chambers. Differential leukocyte counts were performed on blood smears stained with May-Grünwald-Giemsa solution (Merck) as described elsewhere [29].…”

“…The total number of bone marrow cells was quantified in the femoral marrow lavage fluid (FML) that was obtained as described by Fialho de Araú jo et al [29]. Briefly, 24 h after the challenge with OVA (ED15), rats had their femurs removed under deep chloral hydrate (400 mg/kg) anesthesia.…”

Regulation of Allergic Lung Inflammation in Rats: Interaction between Estradiol and Corticosterone

“…The peripheral blood and bone marrow cells were quantified in samples from the tail vein and from the medullary femoral lavage, respectively [18]. Blood aliquots were diluted (1:20) in Türk fluid (3% acetic acid).…”

Estudo da relação entre glândulas salivares e doença periodontal em ratos.

“…Além da manutenção da saúde bucal, as glândulas salivares secretam peptídeos que influenciam na saúde sistêmica do indivíduo (Mathison, 1994), uma vez que eles modulam processos inflamatórios induzidos sistemicamente por LPS ou ovoalbumina (Mathison et al, 1997a(Mathison et al, , 1997bRougeot et al, 2000;Dery, 2001;Fialho de Araújo et al, 2002 ). Até o presente momento, pelo menos 27 peptídeos biologicamente ativos (incluindo calicreína, fator de crescimento nervoso e fator de crescimento epidermal) foram identificados na saliva, e conhecidamente podem atuar como agentes imunossupressores ou imunoestimuladores (Barka, 1980;Amerogen et al, 2002).Ademais, os peptídeos salivares como, por exemplo a proteína rica em prolina, via sítios específicos de adesão presentes em bactérias relacionadas à enfermidade periodontal, ligam-se à elas, as quais inicialmente se agregarão ao biofilme (Arnold et al, 1977;Gibbons e Hay, 1988;Gibbons, 1994;Leung et al, 1990;Alugupalli et al, 1995;Amano et al, 1996;Johansson et al, 2000;Ayad, 2000;Li et al, 2001).…”