Elks M L, Jackson M, Manganiello V C, Vaughan M
Am J Physiol. 1987 Mar;252(3 Pt 1):C342-8. doi: 10.1152/ajpcell.1987.252.3.C342.
The antilipolytic effect of N6-(L-2-phenylisopropyl)-adenosine (PIA), an adenosine analogue thought to act via cell surface receptors, was investigated in 3T3-L1 adipocytes. PIA (1 microM) was as effective as 1 nM insulin in reducing lipolysis stimulated by 1 nM isoproterenol and more effective than insulin at higher isoproterenol concentrations. In intact adipocytes, PIA reduced isoproterenol-induced cyclic AMP (cAMP) accumulation and increased particulate cAMP phosphodiesterase. In particulate preparations PIA suppressed isoproterenol stimulation of adenylate cyclase. PIA was more effective than 5'-N-ethylcarboxamide adenosine (NECA) or adenosine in inhibiting adenylate cyclase and activating phosphodiesterase. In intact adipocytes, two agents with so-called "insulin-like" activities, i.e., anti-insulin receptor antibodies and wheat germ agglutinin (WGA), also increased particulate cAMP phosphodiesterase. Pertussis toxin, which inhibits stimulation of the particulate cAMP phosphodiesterase by insulin (but not by isoproterenol), also inhibited the effects of PIA, anti-insulin receptor antibodies, and WGA. In 3T3-L1 cells, PIA appears to inhibit lipolysis by inhibiting adenylate cyclase and stimulating phosphodiesterase; these effects of PIA, as well as those of anti-insulin receptor antibodies and WGA on phosphodiesterase, may be mediated via guanyl nucleotide-binding proteins.
研究了N6-（L-2-苯异丙基）-腺苷（PIA），一种被认为通过细胞表面受体起作用的腺苷类似物，在3T3-L1脂肪细胞中的抗脂解作用。PIA（1微摩尔）在降低由1纳摩尔异丙肾上腺素刺激的脂解方面与1纳摩尔胰岛素一样有效，并且在较高异丙肾上腺素浓度下比胰岛素更有效。在完整的脂肪细胞中，PIA降低了异丙肾上腺素诱导的环磷酸腺苷（cAMP）积累，并增加了增加了颗粒状cAMP磷酸二酯酶活性。在颗粒制剂中，PIA抑制了异丙肾上腺素对腺苷酸环化酶的刺激。PIA在抑制腺苷酸环化酶和激活磷酸二酯酶方面比5'-N-乙基羧酰胺腺苷（NECA）或腺苷更有效。在完整的脂肪细胞中，两种具有所谓“胰岛素样”活性的物质，即抗胰岛素受体抗体和麦胚凝集素（WGA），也增加了颗粒状cAMP磷酸二酯酶活性。百日咳毒素抑制胰岛素（而非异丙肾上腺素）对颗粒状cAMP磷酸二酯酶的刺激，也抑制了PIA、抗胰岛素受体抗体和WGA的作用。在3T3-L1细胞中，PIA似乎通过抑制腺苷酸环化酶和刺激磷酸二酯酶来抑制脂解；PIA的这些作用，以及抗胰岛素受体抗体和WGA对磷酸二酯酶的作用，可能是通过鸟苷酸结合蛋白介导的。
