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The aim of the present study was to explore the expression changes of P2Y purinergic receptor 1 (P2Y1) in the distal colonic submucosa of opioid-induced constipation (OIC) rats and its association with the occurrence of OIC, an OIC rat model was generated by intraperitoneal injection of loperamide hydrochloride, a selective agonist of µ-opioid receptors (MORs). At 7 days post-treatment, the model was assessed by analyzing stool scores and calculating the gastrointestinal (GI) transit ratio of rats. The distribution of P2Y1-expressing neurons in the colonic submucosal plexus was demonstrated by immunofluorescence (IF). Western blotting was performed to evaluate the expression changes of MOR, P2Y1 and ATP synthase subunit β (ATPB) proteins in the colonic submucosa, while reverse transcription-quantitative PCR (RT-qPCR) analysis was performed to determine the relative mRNA expression of MOR and P2Y1. After 7 days, the feces of OIC rats exhibited an appearance of sausage-shaped pieces and both the stool weight and GI transit ratio of OIC rats were significantly decreased. IF revealed co-expression of P2Y1 and calbindin and MOR and ATPB in the nerve cells of the distal colonic submucosal plexus. Moreover, RT-qPCR analysis showed that the MOR mRNA levels were significantly increased in the distal colonic submucosa of OIC rats, while mRNA levels of P2Y1 were decreased. WB showed that in the distal colonic submucosa of OIC rats, MOR protein expression was increased, whereas that of P2Y1 was significantly decreased. GI transit ratio analysis suggested that the P2Y agonist ATP significantly relieved constipation symptoms in rats, while the P2Y inhibitor MRS2179 aggravated these symptoms. Finally, P2Y1 expression change was shown to be associated with the occurrence of OIC, while expression of MOR and P2Y1 was associated with OIC development in rats.

Aims: To explore the expression changes of P2Y1 in the distal colonic submucosa of opioid induced constipation (OIC) rats and its correlation with the occurrence of OIC. Methods: OIC model was generated by intraperitoneal injection of loperamide hydrochloride, a selective agonist of the μ-opioid receptor (MOR). Seven days later, the model was assessing by detecting the fecal traits and calculating the fecal water cotent. The distribution of MOR-containing neurons and P2Y1-containing neurons in colonic submucosal plexus of rat were demonstrated by immunofluorescence histochemistry. Western Blot was used to evaluate the expression changes of MOR, P2Y1 and ATP synthase subunit beta (ATPB) in colonic submucosa, while the RT-PCR analysis was performed to determine the relative mRNA expression of MOR, P2Y1 and ATPB. Results: After seven days, the feces of OIC rats had an appearance of like sausage-shaped pieces, and the fecal water content, stool weight of OIC rats were decreased. Immunofluorescence histochemistry showed the co-expression of MOR and ATPB, P2Y1 and calbindin (CB) in the nerve cells of distal colonic submucosal plexus. RT-PCR showed that MOR mRNA levels were significantly increased in the distal colonic submucosa of OIC rats, while the mRNA levels of P2Y1 were decreased. Western blot results showed that MOR protein expression was increased, and the P2Y1 protein expression was significantly decreased in the distal colonic submucosa of OIC rats.Conclusion: P2Y1 is associated with the occurrence of OIC in rats, and the expression of MOR and P2Y1 and OIC are correlated with each other.

To find an inhibitor to reduce the volatilization of formalin.The saturated solution of sodium hydrosulphite (SHS) was sprayed on the surface of the anatomy specimens, then the concentration of formaldehyde in the air was tested.The concentration of formaldehyde in the air of SHS sprayed group [(3.10 +/- 1.22) mg/m3] was significantly lower than that of the control group [(8.36 +/- 4.11) mg/m3, P0.01].SHS may be a volatilization inhibitor for formalin, which could reduce the concentration of formaldehyde in the air.