Nongenomic action and mechanism of 17β-estradiol in cytosolic calcium concentration in delayed implantation mouse endometrial stromal cells / 生理学报

To investigate the existence of nongenomic action of 17β-estradiol (E(2)) in the delayed implantation mouse endometrial stromal cells, the changes in intracellular calcium concentration ([Ca(2+)](i)) and the upstream of calcium signal in vitro were detected. The experiment was composed of two parts. Firstly, the change in [Ca(2+)](i) in endometrial stromal cells induced by E(2) under different conditions was detected. The mice were divided into 6 groups as follows: 0.1% dimethylsulfoxide (DMSO) control group, 1×10(-8) mol/L bovine serum albumin (BSA) control group, 1×10(-8) mol/L E(2) group, 1×10(-8) mol/L E(2) conjugated with BSA (E(2)-BSA) group, 1×10(-8) mol/L E(2) + calcium-free medium group, 1×10(-8) mol/L E(2) + 5 mg/mL tamoxifen group, with 4 mice in each group. The endometrial tissue was obtained from delayed implantation mice at pregnant day 7, and digested by incubation of tissue minces in Hankos balanced salts (HBSS, pH 7.2), which contained glucose (1 g/L), and collagenase I (0.125%), for 1 h at 37 degrees C. The stromal cells were preloaded with 2.5 mmol/L Fluo-3/AM, a fluorescent probe of calcium, for 30 min. A confocal laser scanning microscope, which fixed the wave length of excitation and emission at 488 nm and 526 nm, respectively, was used to detect the change in [Ca(2+)](i). Secondly, the mechanism of E(2) effects in endometrial stromal cells was investigated. Immunofluorescent method was used to detect the change in phosphorylation of phospholipase C (PLC) before and after the stromal cells were treated with E(2) for 5 min, 15 min, and 30 min. Seven delayed implantation mice were used. The results were as follows. [Ca(2+)](i) increased immediately and reached the maximum at 15 min after the stromal cells were treated with 1×10(-8) mol/L E(2) and returned to the normal level at 30 min. In E(2)-BSA group and E(2) + calcium-free medium group the same results were obtained as that in E(2) group, but there was no increase of [Ca(2+)](i) in DMSO and BSA groups. Tamoxifen, a traditional antagonist of estrogen receptor, did not inhibit the increase in [Ca(2+)](i) induced by E(2). Immunofluorescent results showed that the change in phosphorylated-PLC level had the same trend as [Ca(2+)](i) after the cells were treated with E(2). Compared with that in the control group, the immunofluorescent intensity increased at the beginning and achieved the maximum at 15 min (P<0.001), then declined to the normal level at 30 min. These results suggest that the rapid response of [Ca(2+)](i) induced by E(2) in the endometrial stromal cells in delayed implantation mice is possibly carried out through a nongenomic pathway, and the transmembrane signal transduction is related to the phosphorylation of PLC in this process.

Study on the effect of volume expansion by 0.9% and 1.8% sodium solution on cardiac-renal reflex in rabbits / 中国应用生理学杂志

<p><b>AIM</b>To study the effect of volume expansion by 0.9% and 1.8% sodium solution on cardiac-renal reflex activity and the role of cardiac-renal reflex in the regulation of integrated function.</p><p><b>METHODS</b>18 health pentobarbital-anaesthetized rabbits were divided evenly into 2 groups at random, bilateral sino-aortic denervation, intubated via right jugular vein to monitor CVP, left renal nerve separated and ending sectioned to record ERSNA, bilateral ureter intubated to collect urine, right femoral intubated to get blood sample. 15% of whole body blood volume of 0.9% and 1.8% sodium solution were injected via jugular vein 10 ml per minute respectively. The CVP, ERSNA, bilateral urine volume and coefficient of sodium excretion were measured before treated, during treated, one minute, five minutes and ten minutes after treated.</p><p><b>RESULTS</b>Volume expansion by 0.9% and 1.8% sodium solution respectively resulted in the increase of CVP by 64.00% +/- 15.56% and 77.00% +/- 23.74%; the decrease of the frequency of ERSNA by 44.00% +/- 13.64% and 63.00% +/- 12.49%, the average burst time of ERSNA by 37.00% +/- 16.49% and 31.00% +/- 10.69%, the increase of average interval of ERSNA bursts by 60.00% +/- 18.38% and 68.00% +/- 27.04%; the increase of urine volume by 158.00% +/- 28.10% and 640.00% +/- 155.39% in left kidney, 192.00% +/- 32.26% and 1343.00% +/- 429.95% in the right; the increase of coefficient of sodium excretion by 132.00% +/- 35.23% and 376.00% +/- 121.72% in the left, 300.00% +/- 76.99% and 856.00% +/- 261.48% in the right.</p><p><b>CONCLUSION</b>Volume expansion by different solution stimulate the receptors of cardiopulmonary and regulate the water and sodium excretion of the kidney by the cardiac-renal reflex to modulate the stabilization of blood volume.</p>