Objective: To observe the effect of intraplantar injection of monosodium iodoacetate (MIA) on pain perception in rats and to investigate the role of transient receptor potential vanilloid type 1 (TRPV1) in the effect....Objective: To observe the effect of intraplantar injection of monosodium iodoacetate (MIA) on pain perception in rats and to investigate the role of transient receptor potential vanilloid type 1 (TRPV1) in the effect. Methods: Adult male Wistar rats were used in the experiment. 1) MIA was injected subcutaneously into the right hindpaw of rats, the low, medium, and high doses of MIA were 0.11, 0.33, and 1 mg, respectively, then the changes of paw withdrawal thermal latency, paw withdrawal mechanical threshold, and dynamic weight bearing within 4 hours after MIA injection were measured. 2) Capsazepine (TRPV1 antagonist, 30 μg) was injected subcutaneously into the right hindpaw of rats at 2 hours after intraplantar injection of MIA (1 mg), then the changes of paw withdrawal thermal latency, paw withdrawal mechanical threshold, and dynamic weight bearing within 1 hour after capsazepine injection were measured. Results: 1) The paw withdrawal thermal latency, paw withdrawal mechanical threshold, and dynamic weight bearing decreased after intraplantar injection of MIA in rats and the effect lasted for at least 4 hours. 2) The MIA-induced reduction in paw withdrawal thermal latency, paw withdrawal mechanical threshold, and dynamic weight bearing were significantly alleviated after intraplantar injection of capsazepine in rats. Conclusion: Intraplantar injection of MIA can produce thermal pain, mechanical pain, and spontaneous pain for more than 4 hours, which may be due to the TRPV1 activation caused by MIA.展开更多
In a newborn affected by a non involuting congenital hemangioma we measured allodynia through the application of a standard tactile stimulus and hyperalgesia through the regular administration of the Comfort scale whi...In a newborn affected by a non involuting congenital hemangioma we measured allodynia through the application of a standard tactile stimulus and hyperalgesia through the regular administration of the Comfort scale which rates pain intensity. The baby presented signs of these pathological events over long periods of the disease. They may be attributed to the high amount of the nociceptive ligands in the hemangioma microenviroment and to the elevated concentration of TNF-alpha and IL-6 in the blood. For a long time, the pain was relieved by a combination of opioids, adjuvants and paracetamol, but also by thalidomide and unexpectedly by interferon alpha. A mechanism-based pain treatment needs to take into account the processes underlying pain and also the ongoing pathology.展开更多
Rats that modeled chronic visceral hyperalgesia received suspended moxibustion at bilateral Tianshu （ST25） and Shangjuxu （ST37） once daily over a period of 7 days. Results show that suspended moxibustion significa...Rats that modeled chronic visceral hyperalgesia received suspended moxibustion at bilateral Tianshu （ST25） and Shangjuxu （ST37） once daily over a period of 7 days. Results show that suspended moxibustion significantly depressed abdominal withdrawal reflex scores and increased enkephalin concentration in the spinal cord. The experimental findings suggest that spinal enkephalins contributed to the analgesic effect of suspended moxibustion in rats with chronic visceral hyperalgesia.展开更多
Prokineticin-1 and prokineticin receptor-1 play important roles in visceral hypersensitivity and in-flammatory pain. Visceral hypersensitivity is closely associated with irritable bowel syndrome. Mild moxibustion can ...Prokineticin-1 and prokineticin receptor-1 play important roles in visceral hypersensitivity and in-flammatory pain. Visceral hypersensitivity is closely associated with irritable bowel syndrome. Mild moxibustion can relieve chronic visceral hyperalgesia in rats with irritable bowel syndrome. We hypothesized that prokineticin-1 and prokineticin receptor-1 is the key target in the mechanism. This study established chronic visceral hyperalgesia rat models by colorectal distention. Protein and mRNA expression of prokineticin-1 and prokineticin receptor-1 were determined by immunohisto-chemical method and fluorescence quantitative-PCR, respectively, and were found to be signifi-cantly increased in visceral hyperalgesic rats. Mild moxibustion at Tianshu （ST 25） decreased prokineticin-1 and prokineticin receptor-1 expression in chronic visceral hyperalgesia rats and lessen the chronic visceral hyperalgesia in rats with irritable bowel syndrome at different levels of colorectal distention pressure.展开更多
AIM:To evaluate the therapeutic effect of Shugan-decoction(SGD)on visceral hyperalgesia and colon gene expressions using a rat model.METHODS:Ninety-six adult male Wistar rats were randomized into six equal groups for ...AIM:To evaluate the therapeutic effect of Shugan-decoction(SGD)on visceral hyperalgesia and colon gene expressions using a rat model.METHODS:Ninety-six adult male Wistar rats were randomized into six equal groups for assessment of SGD effects on psychological stress-induced changes using the classic water avoidance stress(WAS)test.Untreated model rats were exposed to chronic(1 h/d for 10 d consecutive)WAS conditions;experimental treatment model rats were administered with intragastric SGD at1 h before WAS on consecutive days 4-10(low-dose:0.1g/mL;mid-dose:0.2 g/mL;high-dose:0.4 g/mL);control treatment model rats were similarly administered with the irritable bowel syndrome drug,dicetel(0.0042g/mL);untreated normal control rats received no drug and were not subjected to the WAS test.At the end of the 10-d WAS testing period,a semi-quantitative measurement of visceral sensitivity was made by assessing the abdominal withdrawal reflex(AWR)to colorectal balloon-induced distension(at 5 mmHg increments)to determine the pain pressure threshold(PPT,evidenced by pain behavior).Subsequently,the animals were sacrificed and colonic tissues collected for assessment of changes in expressions of proteins related to visceral hypersensitivity(transient receptor potential vanilloid 1,TRPV1)and sustained visceral hyperalgesia(substance P,SP)by immunohistochemistry and real-time polymerase chain reaction.Inter-group differences were assessed by paired t test or repeated measures analysis of variance.RESULTS:The WAS test successfully induced visceral hypersensitivity,as evidenced by a significantly reduced AWR pressure in the untreated model group as compared to the untreated normal control group(190.4±3.48 mmHg vs 224.0±4.99 mmHg,P<0.001).SGD treatments at mid-dose and high-dose and the dicetel treatment significantly increased the WAS-reduced PPT(212.5±2.54,216.5±3.50 and 217.7±2.83 mmHg respectively,all P<0.001);however,the low-dose SGD treatment produced no significant effect on the WAS-reduced PPT(198.3±1.78 mmHg,P>0.05).These trends corresponded to the differential expressions observed for both TRPV1 protein(mid-dose:1.64±0.08 and high-dose:1.69±0.12 vs untreated model:3.65±0.32,P<0.001)and mRNA(0.44±0.16 and0.15±0.03 vs 1.39±0.15,P<0.001)and SP protein(0.99±0.20 and 1.03±0.23 vs 2.03±0.12,P<0.01)and mRNA(1.64±0.19 and 1.32±0.14 vs 2.60±0.33,P<0.05).These differential expressions of TRPV1 and SP related to mid-and high-dose SGD treatments were statistically similar to the changes induced by dicetel treatment.No signs of overt damage to the rat system were observed for any of the SGD dosages.CONCLUSION:Shugan-decoction can reduce chronic stress-induced visceral hypersensitivity in rats,and the regulatory mechanism may involve mediating the expressions of TRPV1 and SP in colon tissues.展开更多
文摘Objective: To observe the effect of intraplantar injection of monosodium iodoacetate (MIA) on pain perception in rats and to investigate the role of transient receptor potential vanilloid type 1 (TRPV1) in the effect. Methods: Adult male Wistar rats were used in the experiment. 1) MIA was injected subcutaneously into the right hindpaw of rats, the low, medium, and high doses of MIA were 0.11, 0.33, and 1 mg, respectively, then the changes of paw withdrawal thermal latency, paw withdrawal mechanical threshold, and dynamic weight bearing within 4 hours after MIA injection were measured. 2) Capsazepine (TRPV1 antagonist, 30 μg) was injected subcutaneously into the right hindpaw of rats at 2 hours after intraplantar injection of MIA (1 mg), then the changes of paw withdrawal thermal latency, paw withdrawal mechanical threshold, and dynamic weight bearing within 1 hour after capsazepine injection were measured. Results: 1) The paw withdrawal thermal latency, paw withdrawal mechanical threshold, and dynamic weight bearing decreased after intraplantar injection of MIA in rats and the effect lasted for at least 4 hours. 2) The MIA-induced reduction in paw withdrawal thermal latency, paw withdrawal mechanical threshold, and dynamic weight bearing were significantly alleviated after intraplantar injection of capsazepine in rats. Conclusion: Intraplantar injection of MIA can produce thermal pain, mechanical pain, and spontaneous pain for more than 4 hours, which may be due to the TRPV1 activation caused by MIA.
文摘In a newborn affected by a non involuting congenital hemangioma we measured allodynia through the application of a standard tactile stimulus and hyperalgesia through the regular administration of the Comfort scale which rates pain intensity. The baby presented signs of these pathological events over long periods of the disease. They may be attributed to the high amount of the nociceptive ligands in the hemangioma microenviroment and to the elevated concentration of TNF-alpha and IL-6 in the blood. For a long time, the pain was relieved by a combination of opioids, adjuvants and paracetamol, but also by thalidomide and unexpectedly by interferon alpha. A mechanism-based pain treatment needs to take into account the processes underlying pain and also the ongoing pathology.
基金supported by the National Basic Research Program of China (973 Program) (No. 2009CB522900)the National Natural Science Foundation of China (No. 30973783)the Shanghai Leading Academic Discipline Project (No. S30304)
文摘Rats that modeled chronic visceral hyperalgesia received suspended moxibustion at bilateral Tianshu （ST25） and Shangjuxu （ST37） once daily over a period of 7 days. Results show that suspended moxibustion significantly depressed abdominal withdrawal reflex scores and increased enkephalin concentration in the spinal cord. The experimental findings suggest that spinal enkephalins contributed to the analgesic effect of suspended moxibustion in rats with chronic visceral hyperalgesia.
基金the National Basic Research Program of China (973 program), No.2009CB522900Shanghai Leading Academic Discipline Project, No. S30304+1 种基金 National Natural Science Foundation of China, No.81001549 Specialized Research Fund for the Doctoral Program of Higher Education, No.200802680001
文摘Prokineticin-1 and prokineticin receptor-1 play important roles in visceral hypersensitivity and in-flammatory pain. Visceral hypersensitivity is closely associated with irritable bowel syndrome. Mild moxibustion can relieve chronic visceral hyperalgesia in rats with irritable bowel syndrome. We hypothesized that prokineticin-1 and prokineticin receptor-1 is the key target in the mechanism. This study established chronic visceral hyperalgesia rat models by colorectal distention. Protein and mRNA expression of prokineticin-1 and prokineticin receptor-1 were determined by immunohisto-chemical method and fluorescence quantitative-PCR, respectively, and were found to be signifi-cantly increased in visceral hyperalgesic rats. Mild moxibustion at Tianshu （ST 25） decreased prokineticin-1 and prokineticin receptor-1 expression in chronic visceral hyperalgesia rats and lessen the chronic visceral hyperalgesia in rats with irritable bowel syndrome at different levels of colorectal distention pressure.
基金Supported by National Natural Science Foundation of China,No.81072786the Innovation Program of the Shanghai Municipal Education Commission,No.12YZ065the Longhua Medical Project,No.D-09
文摘AIM:To evaluate the therapeutic effect of Shugan-decoction(SGD)on visceral hyperalgesia and colon gene expressions using a rat model.METHODS:Ninety-six adult male Wistar rats were randomized into six equal groups for assessment of SGD effects on psychological stress-induced changes using the classic water avoidance stress(WAS)test.Untreated model rats were exposed to chronic(1 h/d for 10 d consecutive)WAS conditions;experimental treatment model rats were administered with intragastric SGD at1 h before WAS on consecutive days 4-10(low-dose:0.1g/mL;mid-dose:0.2 g/mL;high-dose:0.4 g/mL);control treatment model rats were similarly administered with the irritable bowel syndrome drug,dicetel(0.0042g/mL);untreated normal control rats received no drug and were not subjected to the WAS test.At the end of the 10-d WAS testing period,a semi-quantitative measurement of visceral sensitivity was made by assessing the abdominal withdrawal reflex(AWR)to colorectal balloon-induced distension(at 5 mmHg increments)to determine the pain pressure threshold(PPT,evidenced by pain behavior).Subsequently,the animals were sacrificed and colonic tissues collected for assessment of changes in expressions of proteins related to visceral hypersensitivity(transient receptor potential vanilloid 1,TRPV1)and sustained visceral hyperalgesia(substance P,SP)by immunohistochemistry and real-time polymerase chain reaction.Inter-group differences were assessed by paired t test or repeated measures analysis of variance.RESULTS:The WAS test successfully induced visceral hypersensitivity,as evidenced by a significantly reduced AWR pressure in the untreated model group as compared to the untreated normal control group(190.4±3.48 mmHg vs 224.0±4.99 mmHg,P<0.001).SGD treatments at mid-dose and high-dose and the dicetel treatment significantly increased the WAS-reduced PPT(212.5±2.54,216.5±3.50 and 217.7±2.83 mmHg respectively,all P<0.001);however,the low-dose SGD treatment produced no significant effect on the WAS-reduced PPT(198.3±1.78 mmHg,P>0.05).These trends corresponded to the differential expressions observed for both TRPV1 protein(mid-dose:1.64±0.08 and high-dose:1.69±0.12 vs untreated model:3.65±0.32,P<0.001)and mRNA(0.44±0.16 and0.15±0.03 vs 1.39±0.15,P<0.001)and SP protein(0.99±0.20 and 1.03±0.23 vs 2.03±0.12,P<0.01)and mRNA(1.64±0.19 and 1.32±0.14 vs 2.60±0.33,P<0.05).These differential expressions of TRPV1 and SP related to mid-and high-dose SGD treatments were statistically similar to the changes induced by dicetel treatment.No signs of overt damage to the rat system were observed for any of the SGD dosages.CONCLUSION:Shugan-decoction can reduce chronic stress-induced visceral hypersensitivity in rats,and the regulatory mechanism may involve mediating the expressions of TRPV1 and SP in colon tissues.
