Oxytocin decreases colonic motility of cold water stressed rats via oxytocin receptors

AIM: To investigate whether cold water intake into the stomach affects colonic motility and the involvement of the oxytocin-oxytocin receptor pathway in rats.METHODS: Female Sprague Dawley rats were used and some of them were ovariectomized. The rats were subjected to gastric instillation with cold(0-4℃, cold group) or room temperature(20-25℃, control group) saline for 14 consecutive days. Colon transit was determined with a bead inserted into the colon. Colonic longitudinal muscle strips were prepared to investigate the response to oxytocin in vitro. Plasma concentration of oxytocin was detected by ELISA. Oxytocin receptorexpression was investigated by Western blot analysis. Immunohistochemistry was used to locate oxytocin receptors.RESULTS: Colon transit was slower in the cold group than in the control group(P < 0.05). Colonic smooth muscle contractile response to oxytocin decreased, and the inhibitory effect of oxytocin on muscle contractility was enhanced by cold water intake(0.69 ± 0.08 vs 0.88 ± 0.16, P < 0.05). Atosiban and tetrodotoxin inhibited the effect of oxytocin on colonic motility. Oxytocin receptors were located in the myenteric plexus, and their expression was up-regulated in the cold group(P < 0.05). Cold water intake increased blood concentration of oxytocin, but this effect was attenuated in ovariectomized rats(286.99 ± 83.72 pg/mL vs 100.56 ± 92.71 pg/mL, P < 0.05). However, in ovariectomized rats, estradiol treatment increased blood oxytocin, and the response of colonic muscle strips to oxytocin was attenuated.CONCLUSION: Cold water intake inhibits colonic motility partially through oxytocin-oxytocin receptor signaling in the myenteric nervous system pathway, which is estrogen dependent.

PERIPHERAL BLOOD CD34^+ CELL MOBILIZATION IN 42 PATIENTS WITH SEVERE AUTOIMMUNE DISEASE

Objective To evaluate the feasibility and safety of peripheral CD34+ cell mobilization in patients with severe autoimmune disease. Methods Forty-two patients underwent a total of 46 mobilizations by the regimen of cyclophosphamide 2-3 g/m2 +recombinant human granulocyte colony stimulating factor (rhG-CSF) 5 μg·kg-1·d-1. The positive selection of CD34+ cell was performed through the CliniMACS. Results In 8.1±2.3 days after administration of cyclophosphamide, the peripheral white blood cell and mononuclear cell (MNC) decreased to the lowest level. In 3.7±1.6 days after injection of rhG-CSF, the peripheral absolute MNC and CD34+ cell counts were 0.95×109/L and 0.035×109/L, respectively. After 2.4±0.6 times of leukapheresis, there gained 4.46×108/kg of MNC and 5.26×106/kg of CD34+, respectively. After mobilization, the underlying diseases were ameliorated more or less. In systemic lupus erythematosus (SLE) patients, SLE Disease Activity Index (SLEDAI) decreased from a median of 17 to 3 (P<0.01). In rheumatic arthritis patients, an American College of Rheumatology criteria for 20%(ACR20) response was achieved in all five patients. Totally, 17.4% of patients whose absolute neutrophil count <0.5×109/L suffered infection, and 31.0% of patients had bone pain after the injection of rhG-CSF. Two patients suffered severe complications, one with acute renal failure and recovered by hemodialysis, the other died of thrombotic thrombocytopenic purpura. Failed mobilization occurred in three patients. Conclusions Sufficient CD34+ cells can be mobilized by low dose of cyclophosphamide and rhG-CSF. CD34+ cell mobilization for treatment of severe autoimmune disease not only is appropriate in both effectiveness and safety but ameliorates disease also.