@article{oai:niigata-u.repo.nii.ac.jp:00006648,
 author = {Watanabe, Ken-ishi and Hirokawa, Yoichi and Suzuki, Kaoru and Masani, Fumiaki and Shibata, Akira and Tsuchihashi, Hiroshi and Nagatomo, Takafumi},
 issue = {2},
 journal = {Acta medica et biologica, Acta medica et biologica},
 month = {Sep},
 note = {For seven days atenolol (a β-antagonist) and xamoterol (a β-partial agonist) were give orally to healthy volunteers at 50 mg once daily and 100 mg twice daily, respectively. Lymphocyte β-receptor density (Bmax) and affinity (Kd) were determined by radioligand binding assay by using ^<125>I-iodocyanopindolol. Atenolol significantly increased Bmax from 1,566±297 to 3,213±1,134 sites/cell and Kd from 1.12±0.13 to 4.32±2.26 nM. Systolic blood pressure and heart rate were significantly decreased during the treatment with atenolol compared with the basal levels. Xamoterol markedly increased the Bmax and Kd from 1,466±373 and 1.07±0.14 to 7,169±3,768 sites/cell and 6.01±3.84 nM, respectively (p <0.01). But, in contrast to atenolol, the systolic blood pressure increased slightly (p<0.05), and the heart rate was unchanged. Following withdrawal of both drugs, both Bmax and Kd returned to the basal levels. The results indicate that xamoterol up-regulates lymphocyte β-receptors without a decrease in systolic blood pressure, thus suggesting that xamoterol may be beneficial in the treatment of patients with heart failure.},
 pages = {85--89},
 title = {Changes in Human Lymphocyte β-Adrenergic Receptors after Administration of Xamoterol and Atenolol},
 volume = {37},
 year = {1989}
}