Action of anti-M3muscarinic acetylcholine receptor IgG of primary Sjögren's syndrome on the enzymatic antioxidant system in rat submandibular gland.

BACKGROUND: We demonstrate that serum immunoglobulin G (IgG) directed against glandular M3 muscarinic acetylcholine receptors (M3mAChR) and pilocarpine triggers the increment of superoxide dismutase (SOD) and catalase (CAT) and the production of nitric oxide (NO) and prostaglandin E2(PGE2). METHODS: Enzyme-linked immunosorbent assay (ELISA) was performed in the presence of the human M2mAChR synthetic peptide as antigen to detect in serum of pSS patients the autoantibodies. Further, SOD and CAT specific activity and NO were determined chemically in the presence of anti-M3mAChR IgG and pilocarpine. The level of PGE2generation in the presence of autoantibody and pilocarpine was determined by ELISA. RESULTS: An association between anti-M2mAChR autoantibodies and pilocarpine given the increment of the specific activity of SOD and CAT in the serum of pSS patients and in the rat submandibular gland was observed. As a result of this action, M3synthetic peptide and atropine abrogated the stimulatory action. The L-type calcium channel, calcium/calmodulin complex and COX-2 inhibitors selectively blocked the increment of the specific activity of SOD and CAT in the rat submandibular gland. An increased production of NO and PGE2by the cholinergic autoantibody and pilocarpine was also detected. CONCLUSION: On the basis of these results, the increment of the specific activity of SOD and CAT in pSS patients as compared to control healthy individuals may be seen as a defensive reaction to the increment of the amount of ROS, which becoming uncontrollable, leads to irreversible cellular and tissue damage.

Histamine stimulates secretion of extracellular vesicles with nucleotidase activity in rat submandibular gland.

BACKGROUND: Extracellular vesicles released by different cells have been isolated from diverse fluids including saliva. We previously reported that rat submandibular glands secrete nanovesicles that catalyze hydrolysis of ATP, ADP and AMP, which are actors of the purinergic signaling system along with adenosine. Extracellular nucleotides like ATP and adenosine are involved in the regulation of inflammatory processes and apoptosis. Histamine, a widely distributed biogenic amine, is involved in inflammatory response. OBJECTIVE: To test if activation of histamine receptors in rat submandibular gland promotes changes in the release of vesicles with nucleotidase activity that could modulate purinergic signaling. METHODS: Rat submandibular glands were incubated in the absence or presence of histamine and JNJ7777120, an antagonist for H4 receptors. Extracellular vesicles were isolated from incubation media by differential centrifugation. Vesicular nucleotidase activity was measured following Pi release by 3mM MgATP, MgADP or MgAMP. RESULTS: Histamine increased the release of vesicles with nucleotidase activity in a concentration dependent manner. JNJ7777120 significantly reduced this effect. Vesicular nucleotidases obtained in the absence or presence of histamine promoted Pi production from ATP, ADP and AMP. CONCLUSION: The results show a relationship between histamine and the regulation of purinergic signaling, which could be important in the modulation of inflammatory processes.

H(1)-Receptor activation triggers the endogenous nitric oxide signalling system in the rat submandibular gland.

BACKGROUND: Histamine is released from mast cells by immunologic and non-immunologic stimuli during salivary gland inflammation, regulating salivary secretion. The receptor-secretory mechanism has not been studied in detail. AIMS: The studies reported were directed toward elucidating signal transduction/second messenger pathways within the rat submandibular gland associated with 2-thiazolylethylamine (ThEA)-induced H(1)-receptor responses. MATERIALS AND METHODS: To assess the H(1) receptor subtype expression in the rat submandibular gland, a radioligand binding assay was performed. The study also included inositolphosphates and cyclic GMP accumulation, protein kinase C and nitric oxide synthase activities, and amylase release. RESULTS: The histamine H(1) receptor subtype is expressed on the rat submandibular gland with high-affinity binding sites. The ThEA effect was associated with activation of phosphoinositide-specific phospholipase C, translocation of protein kinase C, stimulation of nitric oxide synthase activity and increased production of cyclic GMP. ThEA stimulation of nitric oxide synthase and cyclic GMP was blunted by agents able to interfere with calcium movilization, while a protein kinase C inhibitor was able to stimulate ThEA action. On the other hand, ThEA stimulation evoked amylase release via the H1 receptor but was not followed by the L-arginine/nitric oxide pathway activation. CONCLUSIONS: These results suggest that, apart from the effect of ThEA on amylase release, it also appears to be a vasoactive chemical mediator that triggers vasodilatation, modulating the course of inflammation.

Analgesia preventiva / Preventive analgesia

Acute nociceptive, inflammatory, and neuropatic pain all depend to some degree on the peripheral activation of primary sensory afferent neurons. The prevent administration of drugs can potentially optimize drug concentrations at the site of origin of the pain... At present, the administration of nonsteroidal antiinflammatory drugs, opioids, local anesthetic are being used in a variety of clinical states.