Hu Y, Humphreys-Beher M G
Department of Oral Biology, University of Florida, Gainesville 32610, USA.
Autoimmunity. 1995;21(2):137-42. doi: 10.3109/08916939508993362.
Stimulation of salivary gland secretion by treatment of NOD mice with the beta-adrenergic receptor agonist, isoproterenol, was previously shown to cause a lower accumulation of intracellular cAMP than that found that in BALB/c controls (Hu et al., 1994, Am. J. Physiol. 266: G433). This was, in part, due to decreased levels of beta-adrenergic receptor localized in the plasma membrane. In the present investigation, basal levels of cAMP in the salivary glands of NOD mice were found to be similar to controls, while direct stimulation of adenylate cyclase by incubation of isolated membranes with forskolin showed a reduced cAMP accumulation in NOD mice versus BALB/c control mice. Using direct [3H]-forskolin binding, it was determined that the plasma membranes of NOD mice salivary glands contain reduced levels of membrane-associated adenylate cyclase.
先前的研究表明，用β-肾上腺素能受体激动剂异丙肾上腺素治疗NOD小鼠会刺激唾液腺分泌，但与BALB/c对照小鼠相比，其细胞内cAMP的积累较低（Hu等人，1994年，《美国生理学杂志》266: G433）。这部分是由于质膜中β-肾上腺素能受体水平降低所致。在本研究中，发现NOD小鼠唾液腺中cAMP的基础水平与对照小鼠相似，而用福司可林孵育分离的膜直接刺激腺苷酸环化酶时，与BALB/c对照小鼠相比，NOD小鼠中cAMP的积累减少。通过直接的[3H]-福司可林结合实验，确定NOD小鼠唾液腺的质膜中与膜相关的腺苷酸环化酶水平降低。
