Objective To study the effect of moxonidine (Mox) on the His bundle electrogram (HBE) of normal rabbits. Methods A total of 24 healthy rabbits were randomly divided into four groups: control group, small dose of Mox (0.1 mg?kg -1), medium dose of Mox (0.3 mg?kg -1) and large dose of Mox (0.9 mg?kg -1). The electrode catheter was inserted from the right carotid artery to record the HBE. The HBE and the synchronism surface ECG were recorded before and after intravenous injection. Results In normal rabbits, the R-R interphase, P-R interphase of the ECG and the H-V interphase of the HBE were prolonged in a dose-dependent manner after intravenous injection of Mox. Mox exerted no significant influence on the A-H interphase. Conclusion ① Mox decreases the heart rate of rabbits in a dose-dependent manner in vivo. ② Mox dose-dependently prolongs the P-R interphase of the surface ECG and the H-V interphase of HBE. This indicates that Mox mainly acts on the intraventricular conducting system.

Thirty male weanling WAK strain rats were divided rondomly into 6 groups. All of the diets were pure synthetics according to AOAC. The 1st, 2nd and 3rd group were given diets containing 6, 15 and 24 ppm of zinc respectively, and 10% protein for all three groups, on the other hand, the 4th, 5th and 6th group were given diets containing 5% 10% and 20% of protein respectively, and 15 ppm of zinc.After feeding in stainless steel cage singly for 50 days rats were given intubately solution of 65Zn containing 1.5 ?Ci per 100g of body weight. Then the faeces and urine of rats were collected on 5 consecutive days, and the zinc absorption and retention of all of the tested rats were determined with method of 65Zn as tracer. The results indicated that. (1) The zinc absorption and retention of rats fed on the lowest zinc level were increased significantly. (2) The zinc absorption and retention of rats fed the lowest protein level were decreased significantly, and were improved clearly by increasing protein intake level. (3) The urine excretion of zinc is very low and can not be used as an index in zinc metabolism research. The methodology for determining zinc absorption and retention in organism with method of 65Zn and total zinc is discussed.

Although widely studied, the natural diversity of the hard tick is not well known. In this study, we collected 194 sequences from 67 species, covering 7 genera of hard tick. The 5′ region of the mitochondrial cytochrome c oxidase subunit 1 region (586 bp) has been used to investigate intra- and inter-species variation and the phylogenetic tree of neighbor joining method has been used for assessment. As a result, by comparing the K2P-distance of intra- and interspecies, 30 samples (15.2%) shown that interspecies distance was larger than the minimum interspecfic distance. From the phylogenetic analysis, 86.8% (49) of the species were identified correctly at the genus level. On deeper analysis on these species suggested the possibility of presence cryptic species. Therefore, further work is required to delineate species boundaries and to develop a more complete understanding of hard tick diversity over larger scale.
Cytochromes c ; Cytochromes ; Electron Transport Complex IV ; Ixodidae ; Methods ; Trees

Objective:To evaluate the role of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels in striatum in paclitaxel-induced neuropathic pain and the relationship with GABA B receptors in rats. Methods:Healthy clean-grade male Sprague-Dawley rats, aged 6-9 weeks, weighing 180-220 g, were used in this study.The neuropathic pain model was established by intraperitoneal injection of paclitaxel 2 mg/kg once every 2 days for 7 consecutive days in anesthetized rats, and then intrathecal catheterization was performed.Fifty rats in which intrathecal catheters were successfully implanted were divided into 5 groups ( n=10 each) using a random number table method: paclitaxel group (P group), paclitaxel plus normal saline group(N group), paclitaxel plus lentivirus empty vector group (BV group), paclitaxel plus HCN4 channel lentivirus group (H group), and paclitaxel plus HCN channel inhibitor ZD7288 group (I group). Ten rats of the same age were selected as the blank control group (C group). At 15 days after intraperitoneal injection of paclitaxel, normal saline 20 μl was intrathecally injected in group N, group BV received intrathecal injection of HCN4 channel lentivirus empty vector 1×10 8 TU/ml, 20 μl, group H received intrathecal injection of HCN4 channel lentivirus 1×10 8 TU/ml, 20 μl, and group I received intrathecal injection of ZD728830 μg, 20 μl.The mechanical paw withdrawal threshold (MWT) was measured at 1 day before paclitaxel injection and 14 and 21 days after injection.The cerebral striatum tissues were obtained at T 2, and the expression of HCN4 channel and GABA B receptors was determined by immunohistochemistry and Western blot. Results:Compared with group C, the MWT was significantly decreased, HCN4 channel expression was up-regulated, and GABA B receptor expression was down-regulated in group P ( P<0.05). Compared with group P, the MWT was significantly increased, HCN4 channel expression was down-regulated, and GABA B receptor expression was up-regulated in group H and group I ( P<0.05), and no significant change was found in the parameters mentioned above in group N and group BV ( P>0.05). Conclusion:Up-regulation of expression of HCN4 channels in striatum can induce down-regulation of GABA B receptor expression, which is involved in the pathophysiological mechanism of paclitaxel-induced neuropathic pain in rats.