[Effects of sennosides, rhubarb polysaccharides and emodin on the cytoplasmic free calcium in isolated rat brain cells].
Free intracellular Ca2+ ([Ca2+]i) levels in rat brain were measured by Ca(2+)-sensitive fluorescent indicator Fura-2/Am and the effects of sennoside (SEN), polysaccharides from Rheum palmatum (RPP) and emodin (EMD) were studied. Results showed that the resting [Ca2+]i level in the brain cells was 176.25 +/- 44.67 nmol.L-1 (n = 10) in Ca(2+)-free Hank's solution containing EGTA 0.5 mmol.L-1. After adding CaCl2 (2 mmol.L-1) and KCl (120 mmol.L-1) to the brain cells suspension sequentially, the free [Ca2+]i levels were obviously elevated (P < 0.01) compared with that of resting level. The brain cells were pretreated with SEN (0.07, 0.37 mmol.L-1) for 10 min. In the resting or using the above doses of CaCl2 and KCl, the [Ca2+]i were obviously decreased compared with the control groups (P < 0.01) at the same conditions. RPP dose-dependently decreased the [Ca2+]i. On the contrary, when brain cells were pretreated with EMD (0.037 mmol.L-1) for 10 min, the [Ca2+]i were obviously increased compared with the control groups (P < 0.01) at the same conditions. The results showed that EMD could not only promote the release of intracellular Ca2+ but also the influx of extracellular Ca2+. The opposite effects of the different active components of rhubarb on the [Ca2+]i levels suggest that rhubarb may have different kinds of regulatory functions on brain cells.
Lin
X Z
XZ
Department of Pharmacology, Tianjin Medical University.
Jin
Z H
ZH
D000818:Animals; D000880:Anthraquinones / Q000494:pharmacology*; D001693:Biological Transport, Active / Q000187:drug effects; D001921:Brain / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D004642:Emodin / Q000494:pharmacology*; D011134:Polysaccharides / Q000302:isolation & purification / Q000494:pharmacology*; D051381:Rats; D012676:Senna Extract; D000081226:Sennosides
D000880:Anthraquinones; D004365:Drugs, Chinese Herbal; D011134:Polysaccharides; D000081226:Sennosides; D012676:Senna Extract; D004642:Emodin; D002118:Calcium