Determining 5HT7R's Involvement in Modifying the Antihyperalgesic Effects of Electroacupuncture on Rats With Recurrent Migraine.

Electroacupuncture (EA) is widely used in clinical practice to relieve migraine pain. 5-HT7 receptor (5-HT7R) has been reported to play an excitatory role in neuronal systems and regulate hyperalgesic pain and neurogenic inflammation. 5-HT7R could influence phosphorylation of protein kinase A (PKA)- or extracellular signal-regulated kinase1 / 2 (ERK1 / 2)-mediated signaling pathways, which mediate sensitization of nociceptive neurons via interacting with cyclic adenosine monophosphate (cAMP). In this study, we evaluated the role of 5-HT7R in the antihyperalgesic effects of EA and the underlying mechanism through regulation of PKA and ERK1 / 2 in trigeminal ganglion (TG) and trigeminal nucleus caudalis (TNC). Hyperalgesia was induced in rats with dural injection of inflammatory soup (IS) to cause meningeal neurogenic inflammatory pain. Electroacupuncture was applied for 15 min every other day before IS injection. Von Frey filaments, tail-flick, hot-plate, and cold-plated tests were used to evaluate the mechanical and thermal hyperalgesia. Neuronal hyperexcitability in TNC was studied by an electrophysiological technique. The 5-HT7R antagonist (SB269970) or 5-HT7R agonist (AS19) was administered intrathecally before each IS application at 2-day intervals during the 7-day injection protocol. The changes in 5-HT7R and 5-HT7R-associated signaling pathway were examined by real-time polymerase chain reaction (RT-PCR), Western blot, immunofluorescence, and enzyme-linked immunosorbent assay (ELISA) analyses. When compared with IS group, mechanical and thermal pain thresholds of the IS + EA group were significantly increased. Furthermore, EA prevented the enhancement of both spontaneous activity and evoked responses of second-order trigeminovascular neurons in TNC. Remarkable decreases in 5-HT7R mRNA expression and protein levels were detected in the IS + EA group. More importantly, 5-HT7R agonist AS19 impaired the antihyperalgesic effects of EA on p-PKA and p-ERK1 / 2. Injecting 5-HT7R antagonist SB-269970 into the intrathecal space of IS rats mimicked the effects of EA antihyperalgesia and inhibited p-PKA and p-ERK1 / 2. Our findings indicate that 5-HT7R mediates the antihyperalgesic effects of EA on IS-induced migraine pain by regulating PKA and ERK1 / 2 in TG and TNC.

[Effect of fire-needle intervention on joint function, cartilage impairment and inflammatory response in knee osteoarthritis rats].

OBJECTIVE: To observe the effect of fire-needle stimulation of "Neixiyan"(EX-LE4) and "Dubi"(ST35) on changes of motor function, structure of cartilage degradation and inflammatory factors in knee osteoarthritis (KOA) rats, so as to explore its underlying mechanisms in improving KOA. METHODS: Thirty-nine male SD rats were randomly divided into normal, model and fire-needle groups (n＝13 in each group). The KOA model was established by injection of Monoiodoacetate (MIA, 1 mg) into the lumen of the right knee joint. On the 7th day after successful modeling, fire-needle was applied to EX-LE4 and ST35, twice a week for 3 weeks. The rats' behavioral reactions of gait (0 to 3 points) and claw pressure (0 to 3 points) were scored, and histopathological changes scored by assessing the impairment grade (0 to 6) and stage (0 to 4) of the articular cartilage after safranin O-fast green staining. The contents of serum Interleukin (IL)-1α， Tumor necrosis factor α(TNF-α), IL-10, IL-37 and transforming growth factor ß(TGF-ß) were assayed by ELISA, and ultrastructural changes were observed under transmission electron microscope(TEM). RESULTS: After modeling, the gait and claw-pressure scores were significantly increased in the model group in comparison with the normal group (P<0.05), and the OA score and contents of serum IL-1α and TNF-α were also appa-rently increased in the model group relevant to the normal group (P<0.05，P<0.01), while the levels of serum IL-10, IL-37 and TGF-ß remarkably decreased in the model group in contrast to the normal group (P<0.01). After the intervention, the increase of gait and claw-pressure and OA scores, as well as serum IL-1α and TNF-α contents, and the decrease of serum IL-10, IL-37 and TGF-ß levels were all reversed in the fire needle group (P<0.05, P<0.01). Outcomes of TEM showed more and larger lipid droplets, swollen mitochondria with some vacuoles, and expanded, broken or dissolved rough endoplasmic reticulum in the model group, which was milder in the fire-needle group. CONCLUSION: Fire-needle can improve motor function and relieve impairment of articular cartilage of KOA rats, which may be related to its effects in reducing inflammatory factors and in increasing anti-inflammatory factor levels.

Xenopus laevis is a potential alternative model animal species to study reproductive toxicity of phytoestrogens.

This study investigated effects of phytoestrogen quercetin on the gonadal development in Xenopus laevis. X. laevis at Nieuwkoop and Faber stage 46/47 were exposed to 50, 100 and 200 microg/L quercetin till 1 month postmetamorphosis. Gonads from frogs at 1 and 3 months postmetamorphosis were examined in gross morphology and histology. The highest dose of quercetin as well as estradiol (E2) significantly increased the percentages of phenotypic females. Exposure to quercetin at all doses induced abnormal testes with certain ovarian characteristics to some degree in gross morphology, including ovotestes. The abnormality rate exceeded 10% in each quercetin treatment. Histologic examination revealed that some abnormal testes exhibited intersexuality with testicular structure and ovarian structure or oocytes interspersed in testicular structure at 1 month postmetamorphosis. At 3 months postmetamorphosis, testicular abnormalities were more obvious, such as necrosis or apoptosis of spermatogonia, occurrence of developed or undeveloped oocytes, delay of the development of seminiferous tubes without or less late stage spermatocytes. The results have shown that quercetin cannot only feminize but also impair testicular development of X. laevis, i.e. X. laevis is sensitive to phytoestrogen. It is suggested that X. laevis might be an alternative model species to study reproductive toxicity of phytoestrogens.