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Simple Summary: In order to take blood from pigs or minipigs, they are often secured using a maxillary sling. The animals express strong vocalisations, and the procedure subjectively appears to be stressful for the animals. In the present study, 12 Ellegaard minipigs were operantly conditioned to tolerate blood sampling from the neck without restraint by using positive reinforcement. The aim was to initially quantify the extent of stress during blood sampling; to prove whether minipigs can be trained to tolerate aversive stimuli, such as the insertion of a cannula without fixation; and to prove whether stress can be reduced through training. After an initial blood sample with fixation in the maxillary sling, the animals were trained for 3 weeks, and then blood was taken again, but without fixation. Blood and saliva samples were taken to determine cortisol concentration. Heart rate was measured before and during blood sampling. The results showed no difference in the cortisol concentration in serum between trained and untrained animals, while it was significantly lower in saliva after blood sampling in the trained animals, as was the heart rate. The training proved to be a suitable method to reduce stress when taking blood from pigs. Pigs (and minipigs) are often restrained with a maxillary sling for blood collection. They mainly produce strong vocalisations and show resistance to the procedure, which subjectively appears to be stressful for the animals. The present study investigated whether minipigs can be trained to tolerate aversive stimuli and whether training can reduce stress during blood collection. Blood was taken from 12 Ellegaard minipigs with fixation; thereafter, the animals were trained for 3 weeks using clicker training. Then, blood was taken again, but without fixation. Before and after each blood sample, saliva samples were taken. The cortisol concentration was determined using ELISAs. Serum cortisol was not significantly different before and after training (paired-sample t-test, t (9) = 2.052, p = 0.07). However, salivary cortisol was significantly lower after training (ANOVA (analysis of variance), p-value < 0.001, F-value 6.181). In addition, trained minipigs showed a significantly lower heart rate after blood sampling (paired-sample t-test, t (11) = 4.678, p = 0.001) as well as significantly lower heart rate variability (t (11) = 3.704, p = 0.003) compared to before training. The minipigs could be trained to tolerate aversive stimuli. This contributed to stress reduction when taking blood samples. [ABSTRACT FROM AUTHOR]

In the present study, we evaluated stimulation of the angiotensin type 2 receptor (AT2R) by the selective non-peptide agonist Compound 21 (C21) as a novel therapeutic concept for the treatment of multiple sclerosis using the model of experimental autoimmune encephalomyelitis (EAE) in mice. C57BL-6 mice were immunized with myelin-oligodendrocyte peptide and treated for 4 weeks with C21 (0.3 mg/kg/day i.p.). Potential effects on myelination, microglia and T-cell composition were estimated by immunostaining and FACS analyses of lumbar spinal cords. The in vivo study was complemented by experiments in aggregating brain cell cultures and microglia in vitro. In the EAE model, treatment with C21 ameliorated microglia activation and decreased the number of total T-cells and CD4+ T-cells in the spinal cord. Fluorescent myelin staining of spinal cords further revealed a significant reduction in EAE-induced demyelinated areas in lumbar spinal cord tissue after AT2R stimulation. C21-treated mice had a significantly better neurological score than vehicle-treated controls. In aggregating brain cell cultures challenged with lipopolysaccharide (LPS) plus interferon-γ (IFNγ ), AT2R stimulation prevented demyelination, accelerated re-myelination and reduced the number of microglia. Cytokine synthesis and nitric oxide production by microglia in vitro were significantly reduced after C21 treatment. These results suggest that AT2R stimulation protects the myelin sheaths in autoimmune central nervous system inflammation by inhibiting the T-cell response and microglia activation. Our findings identify the AT2R as a potential new pharmacological target for demyelinating diseases such as multiple sclerosis. [ABSTRACT FROM AUTHOR]

In the present study, we evaluated stimulation of the angiotensin type 2 receptor (AT2R) by the selective non-peptide agonist Compound 21 (C21) as a novel therapeutic concept for the treatment of multiple sclerosis using the model of experimental autoimmune encephalomyelitis (EAE) in mice. C57BL-6 mice were immunized with myelin-oligodendrocyte peptide and treated for 4 weeks with C21 (0.3 mg/kg/day i.p.). Potential effects on myelination, microglia and T-cell composition were estimated by immunostaining and FACS analyses of lumbar spinal cords. The in vivo study was complemented by experiments in aggregating brain cell cultures and microglia in vitro. In the EAE model, treatment with C21 ameliorated microglia activation and decreased the number of total T-cells and CD4+ T-cells in the spinal cord. Fluorescent myelin staining of spinal cords further revealed a significant reduction in EAE-induced demyelinated areas in lumbar spinal cord tissue after AT2R stimulation. C21-treated mice had a significantly better neurological score than vehicle-treated controls. In aggregating brain cell cultures challenged with lipopolysaccharide (LPS) plus interferon-γ (IFNγ), AT2R stimulation prevented demyelination, accelerated re-myelination and reduced the number of microglia. Cytokine synthesis and nitric oxide production by microglia in vitro were significantly reduced after C21 treatment. These results suggest that AT2R stimulation protects the myelin sheaths in autoimmune central nervous system inflammation by inhibiting the T-cell response and microglia activation. Our findings identify the AT2R as a potential new pharmacological target for demyelinating diseases such as multiple sclerosis.