The changes of the expression of 2-type small conductance-Ca- activating-K (SK2) channel protein in hypertensive rat myocardium / 中国应用生理学杂志

OBJECTIVE@#To investigate the expression of 2-type small conductance-Ca-activating-K (SK2) channel protein in hypertensive rat myocardial cells.@*METHODS@#Twelve healthy adult male SD rats were randomly divided into control group (n=5) and experimental group (n=7). The rats of experimental group were injected intraperitoneally with N'-nitro-L-arginine (L-NNA 15 mg/(kg·d))while the rats of control group were injected intraperitoneally with isometrical normal saline(15 ml/(kg·d )). The body weight, blood pressure and electrocardiogram of the rats were measured every week. After 4 weeks, the rats were sacrificed to obtain hearts, and the expression of SK2 channel protein in myocardium was detected by Western blot.@*RESULTS@#After 4 weeks of administration, compared with the control group, the blood pressure in the experimental group was significantly elevated (P＜0.05), QRS duration and R-R interval were prolonged, and the expressions of SK2 channel in the atrial and ventricular tissue of the experimental group were significantly higher than those in the control group (1.12±0.18,1.64±0.26, P ＜ 0.05).@*CONCLUSION@#The expressions of atrial and ventricular SK2 pathway are increased in hypertensive model rats. It may be one of the mechanism leading to arrhythmias in hypertensive model rats and can provide new ideas and strategies for the treatment and prognosis of hypertensive diseases.

Effect of Gastrodia elata on improving sleep in mice and its mechanism / 中草药

Objective: To investigate the sleep promoting effect of Gastrodia elata on mice and its effect on the central dopamine (DA) system, and study the mechanisms of gastrodin, the active constituent of G. elata. Methods: Five groups of mice were treated by gavage with saline, gastrodia, olive oil, gastrodia mixed with olive oil and positive control Estazolam, respectively, for 20 d (10 mice per group). Hypnosis induced by suprathreshold and subthreshold doses of Pentobarbital sodium were used to evaluate the effect of G. elata on sleep in mice. Sleep latency, occurrence rate and duration were recorded at the 7th and 20th day. The DA content in the brain tested by ELISA and the expression of DA receptor subtypes detected by qRT-PCR were used to determine the effect of G. elata on central DA system. Western blotting was further used to detect the expression levels of ERK pathway related protein. Results: After 20 d of gavage, the sleep latency of mice was significantly shortened, the sleep occurrence rate was increased, the sleep duration was prolonged, and the content of brain DA was significantly increased. At the same time, the expression levels of all the dopamine receptor subtypes were significantly up-regulated. Furthermore, the gastrodin, the active constituent of G. elata, could activate the dopamine receptor D2 rather than the D1-mediated signaling pathway. Conclusion: G. elata might regulate sleep by up-regulating the activity of central DA system. Gastrodin, the active constituent of G. elata, could play a regulating role through D2-mediated signaling pathway.

The precision of glomerular filtration rate determined by Gates method and compared with the results from renal pathological changes / 中华核医学杂志

Objective To evaluate the precision of GFR using Gates method and compared with the results from renal pathological changes. Methods Twenty-seven patients whose 99Tcm-DTPA renograms had no obvious uptake phase were enrolled in Group A, and 27 patients whose 99Tcm-DTPA renograms had obvious uptake phase were enrolled in Group B. The measurement of GFR by Gates method was compared to the creatinine clearance measured and predicted by Cockroft-Gault (C-G), modification of diet in renal disease (MDRD) and SCr level. Renal pathological changes in two groups were compared using Pearson correlation and t test analysis. Results In Group A, GFR determined by Gates method did not show correlation with that estimated by C-G or 1/SCr (r = 0. 357,0. 376, both P ＞0.05), but was significantly correlated with GFR estimated by MDRD(r = 0. 440, P ＜ 0.05). In Group B, GFR determined by Gates method showed significantly correlation among GFR estimated by MDRD, C-G, and 1/SCr (r =0. 471, 0. 527,0. 452, all P ＜ 0.05). Renal tubulointerstitial damage score in Group A was higher than that in Group B (7.15±2.32, 3.70±3.06, t=4.66, P ＜0.001). Conclusions GFR determined by Gates method is less precise when 99Tcm-DTPA renogram has no obvious uptake phase than that when 99Tcm-DTPA renogram has obvious uptake phase. Renal tubulointerstitial damage is a strong indicator of no obvious uptake phase in 99Tcm-DTPA renogram.