Chen W R, Liu F, Feng Y J, Zhang J T
Department of Pharmacology, Xinjiang Medical College, Urumqi.
Zhongguo Yao Li Xue Bao. 1995 Nov;16(6):489-92.
To study the effect of nicardipine (Nic) on the cytoplasmic free calcium concentration ([Ca2+]i) in thymocytes and on the proliferation of thymus lymphocytes from mice in vitro.
The [Ca2+]i was measured by loading cells with the fluorescent dye Fura-2. The lymphocyte proliferation was determined by [3H] thymidine incorporation.
Nic 1-30 mumol . L-1 elevated [Ca2+]i of resting thymocytes with the percentages of its increase 43%-192% and 12%-148% in the presence and absence of extracellular Ca2+ respectively. Mitogen Con A 5 mg . L-1 also released Ca2+ from intracellular stores. Nic decreased the enhancement of [Ca2+]i induced by Con A. The IC50 (mumol . L-1) was 26.8 (95% limit: 24.8-29.0) and approximated to 10 in the presence and absence of extracellular Ca2+ respectively. Nic 1-30 mumol . L-1 did not stimulate the proliferation of resting lymphocytes from mouse thymuses (P > 0.05), but inhibited the proliferation when the lymphocytes had been stimulated by Con A (P < 0.01).
Nic elevated [Ca2+]i, which decreased the response of lymphocytes to mitogen.
研究尼卡地平（Nic）对小鼠胸腺细胞胞浆游离钙浓度（[Ca2+]i）及体外胸腺淋巴细胞增殖的影响。
用荧光染料Fura-2负载细胞来测定[Ca2+]i。通过[3H]胸腺嘧啶核苷掺入法测定淋巴细胞增殖。
1-30 μmol·L-1的Nic可升高静息胸腺细胞的[Ca2+]i，在有细胞外Ca2+和无细胞外Ca2+存在时，其升高百分比分别为43%-192%和12%-148%。5 mg·L-1的促有丝分裂原Con A也可从细胞内储存库释放Ca2+。Nic可降低Con A诱导的[Ca2+]i升高。IC50（μmol·L-1）在有细胞外Ca2+和无细胞外Ca2+存在时分别为26.8（95%置信区间：24.8-29.0）和接近10。1-30 μmol·L-1的Nic不刺激小鼠胸腺静息淋巴细胞的增殖（P>0.05），但在淋巴细胞受到Con A刺激时可抑制其增殖（P<0.01）。
Nic升高[Ca2+]i，从而降低淋巴细胞对有丝分裂原的反应。
