ABSTRACT
Objective To investigate effects of hyperpolarization-activated cyclic nucleotide-gated cation nonselective channel in the hu-man ureter on the spontaneous contraction of smooth muscles. Methods Four HCN subtypes were detected in human ureteral tissue using reverse transcription polymerase chain reaction,Western blotting and immunohistochemical. ZD7288,the HCN blocker, was used to observe the changes of ureteral muscle contraction amplitude and frequency by applying the ureteral smooth muscle strip test in vitro. Results HCN1-4 isoforms were all identified in human ureter using reverse transcription-polymerase chain reaction and Western blotting. Through the immunohistochemical,HCN channel was found mostly in the urothelium layer and muscular layer of human ureteral wall. ZD7288 significantly decreased the bladder excitation. Conclusion All 4 HCN channel hypotypes exist in the human ureter, and affect the ureteral excitation.
ABSTRACT
Objective To observe the anisotropy of myocardial fiber orientation and conduction cells in canine pulmonary vein , and to investigate the expression of funny current (If ) channel subunit HCN1 ,HCN2 ,HCN4 mRNA in cadiocytes of pulmonary veins and left atrial in acute atrial fibrillation (AF) modle of caine .Methods Fourteen adult mongrel canines were randomly divided into atrial fibrillation group(n=7) and control group(n=7) .A model of acute AF has been developed in rapid atrial pacing (RAP) . The cardiocytes in control group were detect using hematoxylin hematoxylin and eosin (HE) and Periodic acid-Schiff(PAS) stain in the pulmonary vein .The mRNA expressions of HCN1 ,HCN2 ,HCN4 in two group were quantified by semiquantitative reverse transcription transcription-polymerase chain reaction(RT-PCR) .Results There were complex myocardial fiber orientation in pul-monary veins especially in PV-LA junction .PAS-positive cells could be seen in the endomembrane of pulmonary veins muscle sleeve .There were mRNA expression of HCN2 and HCN4 in pulmonary veins and left arial in two group ,but there was no mRNA expression of HCN1 .The mRNA levels of HCN4 from high to low were:pulmonary veins of atrial fibrillation group ,left atrial of atrial fibrillation group ,pulmonary veins of control group ,left atrial of control group(P0 .05) .Conclusion There are anisotro-py ,conduction cells in pulmonary veins .Up-regulation of pulmonary veins and left atrial HCN 2 ,HCN4 mRNA in atrial fibrillation caine ,may be correlated with the atrial fibrillation and maintenance .
ABSTRACT
It has been suggested that HCN1 is primarily expressed in hippocampus, however little is known about its effects on spatial learning and memory. In the present study, we investigated the effects of non-specific HCN1 blocker CsCl on spatial learning and memory by using Morris water maze and in situ hybridization in mice. The results showed CsCl 160 mg/kg ip for 4 days, and the mean escape latency was 34 s longer than that of normal control (P＜0.01). In hippocampal tissues, staining for the HCN1 mRNA was stronger in the DG and CA1 region of the hippocampus (P ＜0.05, P＜0.05, when CsCl-administration group was compared with normal group). Our results suggested that CsCl could significantly affect the spatial learning and memory in mice, and HCN channel is involved in the process of learning and memory.