ABSTRACT
Objective To evaluate the effect of pretreatment with botulinum toxin A injected intrath?ecally or locally at the incision site on the neurokinin?1 ( NK?1) receptor internalization in the spinal dorsal horn in a rat model of incisional pain. Methods Male Sprague?Dawley rats, weighing 280-300 g, aged 6-8 weeks, were used in the study. The experiment was performed in two parts. ExperimentⅠ Twenty?seven rats with no sign of nerve injury at day 7 after successful catheterization were selected and divided into 3 groups (n=9 each) using a random number table: control group (C1 group), incisional pain group (IP1 group) and intrathecal botulinum toxin A group (BoNT∕A1 group). At 24 h before operation, botulinum tox?in A 0.5 U ( in 10μl of normal saline) was injected intrathecally in group BoNT∕A1, and normal saline 10μl was injected intrathecally in group IP1. ExperimentⅡ Twenty?seven rats were selected and divided into 3 groups (n=9 each) using a random number table: control group (group C2), incisional pain group (IP2 group) and locally injected botulinum toxin A at the incision site group (BoNT∕A2 group). At 24 h before op?eration, botulinum toxin A 2 U ( in 0.4 ml of normal saline) was injected subcutaneously at the incision site and into the plantar surface, and normal saline 0.4 ml was injected subcutaneously at the incision site and into the plantar surface in group IP2. Six rats in each group were selected, and the cumulative pain score (CPS) was recorded, and the mechanical paw withdrawal threshold ( MWT) in the right hindpaw was measured be?fore administration, before operation, and at 3 h and 1, 3, 5 and 7 days after operation. At 3 h after opera?tion, 3 rats in each group were selected and sacrificed, and the lumbar segment ( L4,5 ) of the spinal cord was removed for determination of the expression of NK?1 receptors in the spinal dorsal horn by immunofluores?cence. Results ExperimentⅠ Compared with group C1, the CPS was significantly increased at 3 h and 1, 3, 5 and 7 days after operation, the MWT was significantly decreased at 3 h and 1 and 3 days after opera?tion, and the expression of NK?1 receptors in the spinal dorsal horn was significantly up?regulated in group IP1, and the CPS was significantly increased at 3 h and 1, 3 and 5 days after operation, the MWT was sig?nificantly decreased at 3 h after operation ( P0.05). Compared with group IP1, the CPS was significantly decreased, and the MWT was significantly increased at 3 h and 1, 3, and 5 days after oper?ation, and the expression of NK?1 receptors in the spinal dorsal horn was significantly down?regulated in group BoNT∕A1 (P0.05) . Compared with group IP2, the CPS was significantly decreased at 3 h and 1, 3, and 5 days after operation, the MWT was signifi?cantly increased at 3 h and 1 and 3 days after operation, and the expression of NK?1 receptors in the spinal dorsal horn was significantly down?regulated in group BoNT∕A2 (P<0.05). Conclusion Pretreatment with botulinum toxin A injected intrathecally or locally at the incision site can inhibit the internalization of NK?1 re?ceptors in the spinal dorsal horn in a rat model of incisional pain.
ABSTRACT
Objective To analyze the regulation of estrogen receptor α (ERα) on truncated neurokinin-1 receptor (NK1R-Tr), and the influence of this regulation on cell proliferation in estrogen receptor-positive breast cancer cell lines. Methods The chromatin immune coprecipitation (CHIP) was used to observe the transcriptional regulation function of ERαon NK1R-Tr in breast cancer cells. Luciferase reporter gene assay was used to verify whether ERα played a positive regulatory role in the expression of NK1R-Tr. Western blot assay and real-time-PCR were used to detect the expression of ERα and NK1R-Tr in breast cancer cells, MCF-7 and T47D, as well as the expression of NK1R-Tr protein and mRNA level. NK1R-Tr levels were also detected after using estradiol (E2, ERα agonist) and small interfering RNA (knock out ERα). CCK-8 and clone formation experimen were used to detect the proliferation ability of breast cancer cells after knocking out NK1R-Tr with small interfering RNAs. Results CHIP test and Luciferase reporter gene assay proved that ERα can positively regulate the expression of NK1R-Tr via the ERα sequences in the upstream of the NK1R-Tr gene promoter. The expression of NK1R-Tr at both protein level and mRNA level dropped in the estrogen receptor-positive breast cancer cell line MCF-7 upon knocking out ERα. After knocking out NK1R-Tr, the proliferation ability of estrogen receptor-positive breast cancer cells was lower than that of the control group. Conclusion The ERα positively regulates the expression of NK1R-Tr, resulting in the increased cell proliferation in estrogen positive breast cancer cells.
ABSTRACT
Objective To investigate the role of neurokinin-1 receptor (NK-1R) in the anti-nociceptive effect of enflurane, isoflurane and sevoflurane in mice. Methods Three hundred and twenty Kunming mice of both sexes weighing 20-25 g were randomly divided into4 groups (n =80 each): group normal saline (group NS);group enflurane (group E); group isoflurane (group I) and group sevoflurane (group S). Normal saline (NS) 1.0ml/kg, erflurane 0.5 ml/kg, isoflurane 0.4 ml/kg and sevoflurane 2.0 ml/kg were injected intraperitoneally in NS,E,I and S groups respectively. Each group was further divided into 4 subgroups receiving intrathecal NS 5 μl and Sar-SP (NK-IR agonist) 20, 40 and 80 ng respectively at 5 min after intraperitoneal injection of inhalation anesthetics. The anti-nociceptive effect of the inhalation anesthetics was assessed by tail flick latency (TFL) (the latency for removal of the tail from the path of heat source) and paw-licking time (PLT) after intraplantar formalin injection. Results lntraperitoneal enflurane, isoflurane and sevoflurane significantly prolonged TFL and shortened PLT. Intrathecal Sar-SP 20, 40 and 80 ng significantly shortened TFL dose-dependently but had no significant effeet on PLT as compared with control subgroup. Conclusion NK-1R is involved in the anti-nociceptive effect of enflurane, isoflurane and sevofluran on thermal pain but not chemical and inflammatory pain.
ABSTRACT
Objective To investigate the role of substance P (SP) and its neurokinin-1 receptor (NK-1R) in the pathophysiologic process of Crohn′s disease. Methods In 23 surgical patients of Crohn′s disease and 24 healthy controls, reverse transcription polymerase chain reaction (RT-PCR) was used to determine the mRNA expression of NK-1R, Western blot analysis was used to determine NK-1R protein expression levels, and immunohistochemistry was used to localize expression of NK-1R. Results Compared with normal gut NK-1R mRNA and NK-1R protein in Crohn′s disease were overexpressed. In Crohn′s disease moderate to strong intestinal NK-1R immunoreactivity was found in the lamina propria mononuclear cells, lymphoid follicles, and the surface and crypt epithelium, lymphoid follicles, submucosal vessels, smooth muscle and myoenteric plexus neurones. Conclusions In cases of Crohn′s disease, overexpression of NK-1R may disturb neuropeptides loop balance, and may be involved in the pathophysiological change in this disease.