Dexmedetomidine is a commonly used α2-adreno-ceptor agonist, which affects various organs, including providing beneficial effects on the heart. However, the mechanism underlying the cardiac benefit remains to be fully elucidated. In the present study, it was demonstrated that dexmedetomidine pretreatment on primary cultured rat cardiomyocytes protected against reactive oxygen species (ROS)‑induced apoptosis. In terms of the potential mechanism, it was demonstrated that dexmedetomidine inhibited mitochondrial biogenesis and mitochondrial respiratory complexes, but with increased coupling efficiency. However, dexmedetomidine upregulated mitochondrial membrane potential (Δψm) and resisted against the loss of Δψm induced by carbonilcyanide p‑triflouromethoxyphenylhydrazone. Due to the importance of mitochondria affecting ROS, the present study investigated the dexmedetomidine‑suppressed mitochondrial response to H2O2 stimulation, which was explained by suppressed ROS levels and the suppression of the increased oxygen consumption rate. Results demonstrated for the first time, to the best of our knowledge, a novel protective mechanism for dexmedetomidine on cardiomyocytes through the attenuated response of mitochondria towards H2O2, which had a protective effect against ROS‑induced apoptosis.

In this experiment, the effects of soybean antigen proteins on intestinal permeability, 5-hydroxytryptamine (5-HT) levels and secretory IgA (sIgA) distribution in the intestine of weaned piglets were evaluated. Thirty piglets (21 d of age) were randomly divided into three groups: control group, glycinin-sensitised group and b-conglycinin-sensitised group. Piglets in the control group were fed a basal diet, and in two sensitised groups were fed the diet with 4% glycinin or b-conglycinin. Piglets in glycinin and b-conglycinin groups were sensitised twice on 21-27 d and 32-34 d period, respectively. Blood samples were collected and analysed for D-lactic acid, diamine oxidase (DAO) and 5-HT levels on d 21, 28 and 35. At the end of the trial, five piglets per group were sacrificed and the small intestine was collected to evaluate intestinal sIgA distribution and the optical density (OD) of the relative staining positivity. The results revealed that the piglets in glycinin and b-conglycinin groups had higher D-lactic acid, DAO and 5-HT levels than those of the control group (p < 0.01). Similarly, OD values were higher in the treatment groups than in the control group (p < 0.01). The intestinal sections, in order of decreasing OD value, were middle jejunum > duodenum > proximal jejunum and distal ileum > distal jejunum. These results suggest that soybean antigen proteins induce allergic reactions, damage the intestinal mucosa, increase intestinal permeability and promote sIgA synthesis in weaned piglets. ARTICLE HISTORY

Glycinin, an antigenic glycoprotein found in soybeans, is the major cause of allergic reactions in young animals. The objective of this study was to evaluate the effects of a prior immunisation of sucking piglets with glycinin on their post-weaning growth performance, serum immunoglobulin contents, small intestinal histamine release and mucosal histology. Forty piglets (7 d of age) were randomly divided into four groups of 10 piglets each. Piglets of Group C (Control) received a physiological saline solution, Groups Im (Immunised) and Im þ S (Sensitised) were immunised twice with 500 lg/kg of glycinin at 7 and 21-d-old. All piglets were weaned at 23 d; Groups Im þ S and S were sensitised with 2500 lg/kg of glycinin at weaning. Compared with Group C, in Group S the average daily gain (ADG), average daily feed intake and gain:feed ratio were decreased, and serum levels of IgG and IgE were increased. Furthermore, in this group, the histamine levels in the duodenum and ileum were significantly decreased, and the structure of duodenal and ileal mucosa was severely damaged. On the contrary, in Groups Im and Im þ S the ADG was increased, serum IgE levels were decreased, intestinal histamine levels were increased and the intestinal mucosa was not damaged. These findings suggest that prior immunisation with glycinin can protect the structural integrity of the intestinal mucosal epithelia and alleviate allergic reactions in piglets.ARTICLE HISTORY

No abstract