Nwosu U C, Rice P J
Department of Obstetrics and Gynecology, James H. Quillen College of Medicine, East Tennessee State University, Johnson City 37614, USA.
Proc Soc Exp Biol Med. 1995 Jun;209(2):157-62. doi: 10.3181/00379727-209-43890.
Leukocyte beta 2-adrenoceptors mirror similar receptors in the uterus. This study examined changes in beta 2-adrenoceptors and in cAMP production during pregnancy using peripheral mononuclear leukocytes isolated from 17 pregnant women and 5 nonpregnant controls. beta 2-Adrenoceptor density was determined by 125I-pindolol binding. cAMP production under basal and stimulated (10 microM isoproterenol) conditions was determined by radioimmunoassay. Groups were compared by unpaired t test. There was a nonsignificant decrease in the density of beta-adrenoceptors during pregnancy. While basal cAMP production was unchanged during pregnancy, stimulated cAMP production was decreased (44% of control, P < 0.001; 95% CI 33%-56%). Stimulated cAMP production per receptor was lower in leukocytes from pregnant women and was not a constant relationship, but was increased markedly in leukocytes having fewer than 400 beta-adrenoceptor sites per cell. There are significant changes in the coupling of beta-adrenoceptors to cAMP production during pregnancy without changes in beta-receptor density, affinity, or basal cAMP production.
白细胞β2-肾上腺素能受体与子宫中的类似受体相似。本研究使用从17名孕妇和5名非孕妇对照组中分离出的外周单核白细胞，检测了孕期β2-肾上腺素能受体及环磷酸腺苷（cAMP）生成的变化。通过125I-吲哚洛尔结合法测定β2-肾上腺素能受体密度。采用放射免疫分析法测定基础状态及刺激状态（10微摩尔异丙肾上腺素）下的cAMP生成量。通过成组t检验对各组进行比较。孕期β-肾上腺素能受体密度有不显著的下降。虽然孕期基础cAMP生成量未变，但刺激后的cAMP生成量下降（为对照组的44%，P<0.001；95%可信区间为33%-56%）。孕妇白细胞中每个受体刺激后的cAMP生成量较低，且并非恒定关系，但在每个细胞β-肾上腺素能受体位点少于400个的白细胞中显著增加。孕期β-肾上腺素能受体与cAMP生成的偶联有显著变化，而β-受体密度、亲和力或基础cAMP生成量无变化。
