Antihistaminic drugs modify casein-induced inflammation in the rat

Introduction

All known antihistaminics may affect several inflammatory events, including chemotaxis, the survival of eosinophils, and the release of chemokines and cytokines from different sources, thus highlighting the potential for modulating chronic inflammation and immune responses. The aim of the study was to examine the effect of H₁–H₄ antihistaminic drugs in an acute model of casein-induced inflammation in rat.

Materials and methods

Inflammation was induced by injection of a 12% solution of casein into the peritoneal cavity of male Wistar rats. The rats were treated intraperitoneally with pyrilamine maleate (10 mg/kg), cimetidine (25 mg/kg), thioperamide maleate (2 mg/kg) or ciproxifan hydrogen maleate (0.14 mg/kg) twice: 2 hours prior and 4 hours after casein administration. The level of histamine in blood and chemiluminescence of stimulated and unstimulated PMNs was measured.

Results

The level of histamine in the casein-induced inflammation group was higher than in the control group. Treatment with pyrilamine and ciproxifan additionally increased the level of blood histamine during the inflammatory response. Peripheral blood neutrophils from rats with casein-induced inflammation tended to respond less to zymosan stimulation than the neutrophils in the controls. Selective H₁ and H₃ antagonists injected into the rats with casein-induced inflammation significantly increased the response of the neutrophils to zymosan (p < 0.01).

Conclusion

Histamine produced or released into the blood in the course of experimental inflammation exerts its effects on the PMN-s via stimulation of H₁ and H₃ receptors.

     

Cryotherapy decreases histamine levels in the blood of patients with rheumatoid arthritis

Introduction

Conventional physiotherapy (electrotherapy, magnetic fields), kinesitherapy, and whole-body cryotherapy (plus kinesitherapy) are used to relieve pain and inflammation or to improve function in rheumatic diseases. The aim of this study was to investigate the effects of different physiotherapies and cryotherapy on biochemical blood parameters of patients with rheumatoid arthritis (RA) and osteoarthritis (OA).

Materials and methods

Twenty patients with RA and 17 patients with OA received whole-body cryotherapy at −140 to −160°C for 2 to 3 min, once daily for 4 weeks. The second group of patients (24 with RA and 28 with OA) received conventional physiotherapy for 4 weeks. We measured the parameters of neutrophil activation (respiratory burst, calprotectin) and markers of cartilage metabolism [N-acetyl-beta-D-hexosaminidase (NAHase), ectonucleotide pyrophosphohydrolase (NTPPHase)] twice: before and 3 months after cryotherapy or physiotherapy.

Results

We showed, for the first time, that cryotherapy significantly reduced (P < 0.001) histamine levels in the blood of patients with RA. The effect was long-lasting (for at least 3 months). The levels of blood histamine in patients with OA were not changed significantly. Cryotherapy also downregulated the respiratory burst of PMNs and NAHase activity and upregulated calprotectin levels and the activity of NTPPHase. However, these changes were not statistically significant. In contrast, there were no significant changes in histamine levels or the other biochemical parameters measured in groups of patients treated only with physiotherapy and kinesitherapy.

Conclusion

It may be concluded that the beneficial clinical effects of cryotherapy in RA patients are in part due to the action on the production, release, or degradation of histamine.

     

Histamine in pericarditis of children with congenital heart malformations

Introduction

Congenital heart malformations are risk factors that make children susceptible to infections resulting in inflammation.

Material and methods

The concentration of histamine as a modulator of inflammation was quantified in pericardial fluid and expression of histamine H₄ receptor (H₄R) and histamine-releasing factor (HRF) was determined at mRNA and protein levels. Samples of pericardium and pericardial fluid were obtained during cardiac reconstruction surgery in children.

Results

In children with pericarditis, increased levels of histamine were found and expression of H₄R was localized on mast cells. Expression of HRF was independent of presence or absence of inflammation in pericardium and was localized within stationary epithelial cells.

Conclusion

Results indicate that involvement of H4R in pericardial inflammation depends on penetration of mast cells into inflamed tissue, but HRF may not be directly involved in inflammatory reaction of the pericardium.

     

Antihistaminic drugs modify casein-induced inflammation in the rat

Introduction

All known antihistaminics may affect several inflammatory events, including chemotaxis, the survival of eosinophils, and the release of chemokines and cytokines from different sources, thus highlighting the potential for modulating chronic inflammation and immune responses. The aim of the study was to examine the effect of H₁–H₄ antihistaminic drugs in an acute model of casein-induced inflammation in rat.

Materials and methods

Inflammation was induced by injection of a 12% solution of casein into the peritoneal cavity of male Wistar rats. The rats were treated intraperitoneally with pyrilamine maleate (10 mg/kg), cimetidine (25 mg/kg), thioperamide maleate (2 mg/kg) or ciproxifan hydrogen maleate (0.14 mg/kg) twice: 2 hours prior and 4 hours after casein administration. The level of histamine in blood and chemiluminescence of stimulated and unstimulated PMNs was measured.

Results

The level of histamine in the casein-induced inflammation group was higher than in the control group. Treatment with pyrilamine and ciproxifan additionally increased the level of blood histamine during the inflammatory response. Peripheral blood neutrophils from rats with casein-induced inflammation tended to respond less to zymosan stimulation than the neutrophils in the controls. Selective H₁ and H₃ antagonists injected into the rats with casein-induced inflammation significantly increased the response of the neutrophils to zymosan (p < 0.01).

Conclusion

Histamine produced or released into the blood in the course of experimental inflammation exerts its effects on the PMN-s via stimulation of H₁ and H₃ receptors.

     

The effect of leptin on the respiratory burst of human neutrophils cultured in synovial fluid

Objectives

Leptin is a hormone responsible for nutritional status and immune competence coordination. In rheumatoid arthritis (RA) increased leptin levels were observed in both serum and synovial fluid. Its influence on development of the disease still remains unclear. So far, research on leptin''s influence on the emission of reactive oxygen intermediates (ROI) measured with chemiluminescence (CL) has provided unclear and contradictory results. In this study, we evaluated the influence of leptin on oxidative activity of neutrophils isolated from blood of healthy volunteers and cultured in different amounts of synovial fluid (SF) from patients with RA.

Material and methods

Neutrophils’ oxidative metabolism was measured by two types of CL. The first one, luminol-dependent CL (CL-lum), allows one to determine phagocytic activity and the level of ROI generated in a myeloperoxidase-dependent manner. The second method used was lucigenin-dependent CL (CL-luc), which monitors ROI production dependent on the NADPH oxidase enzyme complex located in the cell membranes of neutrophils and enables one to determine the scope of extracellular ROI emission.

Results

Neutrophils stimulated by opsonized zymosan show a decrease in the level of CL-lum, proportional to the increasing concentration of both SF and serum collected from healthy donors. The observed effect of decreased CL-lum may, therefore, be dependent on the physical conditions (viscosity of fluids used). None of these experiments showed any effect of leptin on the level of CL-lum.

Conclusions

The present study showed that leptin does not affect the level of any of the CL types in inactive neutrophils incubated in normal serum, and it does not affect the level of oxidative activity in resting neutrophils incubated with SF. However, leptin influences extracellular ROI emission (measured by CL-luc). Leptin reduces extracellular emission of ROI, and this effect is dependent on concentration and duration of exposure to leptin.     

Histamine chloramine modifies casein-induced inflammation

Inflammation Research -     

The role of physiological elements in future therapies of rheumatoid arthritis. III. The role of the electromagnetic field in regulation of redox potential and life cycle of inflammatory cells

Each material consisting of charged particles can be influenced by a magnetic field. Polarized particles play an essential role in almost all physiological processes. Locally generated electromagnetic fields several physiological processes within the human body, for example: stimulation of nerves, muscles, and cardiac electrical activity. This phenomenon is used today in many medical applications. In this article, we discuss ways in which electromagnetic field affects the physiological and pathological processes in cells and tissues. This knowledge will help to better understand the electrophysiological phenomenon in connective tissue diseases and can bring new therapeutic strategies (in the form of “invisible drugs”) for the treatment of rheumatic diseases?     

The role of physiological elements in the future therapies of rheumatoid arthritis. II. The relevance of energy redistribution in the process of chronic inflammation

The reasons for development of chronic inflammation are complex and not fully understood. One of the factors affecting the prolongation of inflammation is changes in cell metabolism, occurring at the center of the inflammatory process. In chronic inflammation there is an imbalance between the processes of storage and consumption of energy reserves. Hypoxia that is a consequence of edema results in transition of white blood cells to anaerobic metabolism. Neutrophils, lymphocytes and macrophages produce active oxygen metabolites which on one hand facilitate the elimination of pathogens, and on the other hand, can cause damage to healthy cells located in the inflamed tissue. In this paper, we discuss the importance of disturbed redistribution of energy as one of the main reasons for transformation of the acute inflammatory process into the chronic one.     

Antinociceptive properties of esculetin in non‐inflammatory and inflammatory models of pain in rats

Some studies suggest that 5‐lipoxygenase (5‐LOX) inhibition or leukotriene receptor antagonism may effectively attenuate different kinds of pain. In the present study, we investigated whether esculetin (which, among other actions, potently inhibits 5‐LOX) possesses analgesic activity in acute non‐inflammatory pain and acute inflammatory pain models in rats. We also examined the effects of zileuton, a selective 5‐LOX inhibitor, on esculetin activity. Plasma concentrations of leukotriene B₄ (LTB₄) after administration of esculetin were also determined. Esculetin (1.25–20 mg/kg, i.p.) dose‐dependently alleviated hyperalgesia and exhibited antinociceptive effects in both experimental models. The greatest effect of esculetin was observed with a dose of 20 mg/kg. In carrageenan‐induced inflammatory pain in rats, 20 mg/kg esculetin reversed or mitigated hyperalgesia, increasing the threshold to mechanical stimuli from a control value of ?23.8 ± 1.8% to 15.2 ± 2.2% (P < 0.01) and that to thermal stimuli from ?52.5 ± 6.1% to ?9.5 ± 3.9% (P < 0.01). In non‐inflammatory pain, after esculetin (20 mg/kg) administration the threshold values to mechanical and thermal stimuli increased to 75.9 ± 4.2% and 59.2 ± 4.3%, respectively (P < 0.01 for both). Zileuton (30 mg/kg, p.o.) alone slightly but significantly increased the pain threshold in the non‐inflammatory and inflammatory acute pain models. Pretreatment with 30 mg/kg, p.o., zileuton significantly enhanced the analgesic activity of 5 mg/kg, i.p., esculetin in both pain models. Moreover, esculetin (10 mg/kg, i.p.) decreased LTB₄ concentrations in the blood from 244 ± 29 pg/mL in the control group to 185 ± 11 pg/mL (P < 0.005). The results of the present study suggest the involvement of the 5‐LOX pathway in esculetin analgesia.