Viticchi C, Rossolini G, Piantanelli L
Gerontological Research Department, Italian National Research Centers on Aging (INRCA), Ancona.
Ann N Y Acad Sci. 1992 Apr 15;650:105-8. doi: 10.1111/j.1749-6632.1992.tb49104.x.
Previous experimental results have demonstrated progressive impairments in beta-adrenergic responsiveness with advancing age. Beta-adrenoceptors are involved in the alterations as their density progressively decreases during aging. Alterations in both in vivo responsiveness and receptor density are corrected by neonatal thymic grafts. In the present paper adenylyl-cyclase (AC) activity has been studied in the same animal models used before. Results show that no statistically significant changes can be observed when AC is assayed in absence of beta-adrenergic stimulation. On the contrary, when assayed after Isoproterenol stimulation, AC activity shows a shift of the peak and a decrease of its height in aged animals. A neonatal thymus grafted into old recipients one month before the experiment was performed, is capable of correcting the altered height of the peak but not the peak concentration.
先前的实验结果表明，随着年龄的增长，β-肾上腺素能反应性会逐渐受损。β-肾上腺素受体参与了这些变化，因为在衰老过程中它们的密度会逐渐降低。新生胸腺移植可纠正体内反应性和受体密度的改变。在本文中，我们在之前使用的相同动物模型中研究了腺苷酸环化酶（AC）的活性。结果表明，在没有β-肾上腺素能刺激的情况下检测AC时，未观察到统计学上的显著变化。相反，在用异丙肾上腺素刺激后检测时，老年动物的AC活性显示出峰值的偏移和高度的降低。在实验前一个月将新生胸腺移植到老年受体中，能够纠正峰值高度的改变，但不能纠正峰值浓度。
