Singer-Lahat D, Lotan I, Itagaki K, Schwartz A, Dascal N
Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Ramat Aviv, Israel.
Biochim Biophys Acta. 1992 Oct 6;1137(1):39-44. doi: 10.1016/0167-4889(92)90097-u.
Ba(2+)-currents (IBa) through voltage-dependent Ca(2+)-channels were studied in Xenopus oocytes injected with RNA from several excitable tissues, using the two-electrode voltage-clamp technique. Previous studies have shown that the expression of cardiac Ca(2+)-channels can be suppressed by an hybrid-arrest procedure that includes co-injection of the tissue-derived RNA with an 'antisense' oligonucleotide complementary to a part of RNA coding for the Ca(2+)-channel alpha 1 subunit. In this study, this method was used to investigate the role of the alpha 2/delta subunit. Co-injection of RNA extracted from either rabbit heart, rat brain or rat skeletal muscle (SkM) with 'antisense' oligonucleotides complementary to the alpha 2/delta subunit RNA did not substantially affect the expression of IBa in the oocytes. Using the Northern blot hybridization method, it was shown that native oocytes contain large amounts of alpha 2/delta subunit RNA of Ca(2+)-channel. It is proposed that te oligonucleotide treatment fails to eliminate the alpha 2/delta RNA because of the vast excess of endogenous alpha 2/delta RNA. These results impose a limit on the use of the hybrid-arrest method.
运用双电极电压钳技术，在注射了来自多种可兴奋组织RNA的非洲爪蟾卵母细胞中，研究了通过电压依赖性钙通道的Ba(2+)电流（IBa）。先前的研究表明，心脏钙通道的表达可通过一种杂交抑制程序来抑制，该程序包括将来自组织的RNA与一种与编码钙通道α1亚基的RNA部分互补的“反义”寡核苷酸共同注射。在本研究中，此方法用于研究α2/δ亚基的作用。将从兔心脏、大鼠脑或大鼠骨骼肌（SkM）中提取的RNA与与α2/δ亚基RNA互补的“反义”寡核苷酸共同注射，并未显著影响卵母细胞中IBa的表达。使用Northern印迹杂交法表明，天然卵母细胞含有大量钙通道的α2/δ亚基RNA。有人提出，由于内源性α2/δ RNA大量过剩，寡核苷酸处理未能消除α2/δ RNA。这些结果限制了杂交抑制方法的应用。
