Raval J, Joshua I G, Webb R C, Bohr D F
Department of Physiology, University of Michigan, Ann Arbor 48109.
J Hypertens Suppl. 1989 Dec;7(6):S146-7. doi: 10.1097/00004872-198900076-00069.
The effects of lanthanum on the contraction induced by the protein kinase C activator, 12-O-tetradecanoylphorbol-13-acetate (TPA) were studied in femoral artery rings from stroke-prone, spontaneously hypertensive rats (SHRSP) and normotensive Wistar-Kyoto rats (WKY). When exposed to a calcium-free buffer containing 1 mmol/l EGTA, the femoral artery rings from SHRSP and WKY, pre-contracted with TPA (10(-6) mol/l), relaxed by 52 and 24%, respectively. Treatment of the rings in this calcium-free buffer with 2.6 mmol/l lanthanum significantly potentiated the TPA-induced contractions in vascular rings from WKY (49%) and SHRSP (136%). Potentiation by lanthanum of the TPA-induced contraction in the absence of extracellular calcium suggests that this cation is acting intracellularly to increase protein kinase C activity. The increased vascular responsiveness of SHRSP to lanthanum may reflect an abnormality in protein kinase C activation in vascular smooth muscle of genetically hypertensive rats.
研究了镧对易卒中型自发性高血压大鼠（SHRSP）和正常血压的Wistar-Kyoto大鼠（WKY）股动脉环中蛋白激酶C激活剂12-O-十四烷酰佛波醇-13-乙酸酯（TPA）诱导收缩的影响。当暴露于含有1 mmol/L乙二醇双四乙酸（EGTA）的无钙缓冲液中时，预先用TPA（10⁻⁶ mol/L）预收缩的SHRSP和WKY的股动脉环分别松弛了52%和24%。在这种无钙缓冲液中用2.6 mmol/L镧处理血管环，可显著增强WKY（49%）和SHRSP（136%）血管环中TPA诱导的收缩。在无细胞外钙的情况下镧对TPA诱导收缩的增强作用表明，这种阳离子在细胞内起作用以增加蛋白激酶C的活性。SHRSP对镧的血管反应性增加可能反映了遗传性高血压大鼠血管平滑肌中蛋白激酶C激活的异常。
