IL-6 inhibits colonic longitudinal muscle contraction by inactivating L-type calcium channel in rats with pancreatitis / 生理学报

The aim of this study was to investigate the effect of interleukin 6 (IL-6) on the contraction of colon longitudinal muscle strips in rats with acute pancreatitis (AP) and its underlying mechanism. Rat AP model was established by combined injection (i. p.) of ceruletide and lipopolysaccharide. The effect of IL-6 on spontaneous contraction of longitudinal smooth muscle strips of rat colon was observed by biological function experiment system. The level of serum IL-6 was detected by ELISA, the expression and distribution of IL-6 in colon were observed by histochemical staining, and the effect of IL-6 on L-type calcium channel in colon smooth muscle cells was observed by whole cell patch clamp technique. The results showed that, compared with the control group, AP group exhibited reduced contractile amplitude and longer contraction cycle of colon smooth muscle strips. IL-6 prolonged the contraction cycle of colon smooth muscle strips, but did not affect their spontaneous contraction amplitude. Serum IL-6 concentration in AP group was significantly higher than that in control group (P > 0.05). IL-6 was diffusely distributed in the colon of the control group, but the expression of IL-6 was significantly up-regulated in the colon gland, mucosa and submucosa of the AP group. IL-6 significantly decreased the peak current density of L-type calcium channel in rat colon smooth muscle cells. These results suggest that the colon motility of AP rats is weakened, and the mechanism may be that up-regulated IL-6 inactivates L-type voltage-dependent calcium channels, and then inhibits the contraction of colon longitudinal smooth muscle.

Intravenous injection rate and site of fentanyl affect the incidence and onset time of fentanyl-induced cough / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effect of intravenous injection rate and site of fentanyl on the incidence and onset time of fentanyl-induced cough.</p><p><b>METHOD</b>Seventy-five ASA class I or II patients were randomized into 3 groups and received intravenous fentanyl administration at 4 microg/kg in different manners. In group A, fentanyl was injected within 2 s into the forearm veins; in group B, fentanyl was injected in 2 s through the dorsal foot veins or the great saphenous vein anterior to the ankle; in group C, fentanyl was injected in 15 s by the same route as in group A.</p><p><b>RESULTS</b>The incidence of cough was 44%, 52% and 8%, with cough onset time of 16.1-/+2.7 s, 21.9-/+3.7 s and 23.3-/+3.2 s in groups A, B and C, respectively. Compared with group A, group B had a delayed onset of cough (P<0.05), and group C had both a lowered incidence of cough (P<0.05) and delayed onset of cough (P<0.05).</p><p><b>CONCLUSIONS</b>The rate of fentanyl injection through the same peripheral venous access at the same dose may affect the incidence and onset time of cough. At the same dose and injection rate of fentanyl, forearm venous access of injection resulted in earlier onset of cough than lower limb venous access, but the incidence is similar.</p>

Low-dose ketamine combined with fentanyl for intravenous postoperative analgesia in elderly patients / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the clinical efficacy of and complications arising from low-dose ketamine combined with fentanyl for intravenous postoperative analgesia in comparison with the exclusive use of fentanyl in elderly patients.</p><p><b>METHODS</b>Eighty elderly patients were randomized into two equal groups following thoracoabdominal surgery, and received intravenous analgesia with the combination of 0.5 mg/ml ketamine, 5.0 microg/ml fentanyl and 50 microg/ml midazolam (KF group) and with 7.5 microg/ml fentanyl plus 50 microg/ml midazolam (FT group), respectively. The drugs used were diluted in 200 ml normal saline. For analgesic administration, a loading dose (2-4 ml) was given followed by a background infusion (2.5-3.5 ml), with patient-controlled bolus doses of 2.0-3.0 ml with lock-out time of 20 min via PCA pump (Automedical, Korea). The static pain score (VAS), sedation score, and incidences of nausea, vomiting, pruritus and hallucinations were recorded during the initial 48 h after the surgery.</p><p><b>RESULTS</b>The total analgesic dosage and PCA dosage in the two groups were similar (P>0.05). With similar VAS in the two groups (P>0.05), the sedative effect in KF group was much better than that in FT group (P<0.05) during the initial 48 h postoperatively. The incidences of nausea, vomiting and itching were lower in KF group than in FT group (P<0.05), and no illusion was reported in two groups during the initial 48 h.</p><p><b>CONCLUSION</b>For producing comparable postoperative analgesic effect, low-dose ketamine combined with fentanyl can markedly reduce fentanyl requirement in the elderly patients and lowers the incidences of nausea, vomiting and itching in comparison with the exclusive use of fentanyl.</p>