环核苷酸(cAMP,cGMP)是体内儿茶酚胺和肽类激素以及各种药物作用的中间环节。体内各种各样生理效应无不涉及到这二种重要的调节物质。正常状态下,细胞内cAMP比cGMP高1～2个数量级,二者浓度分别为10~(-7)～10~(-6)、10~(-9)—10~(-8)克分子。它可以通过细胞膜进入体液,而细胞外的环核苷酸也可被细胞所摄取,胞内外发生迅速双向流动。人体cAMP产生率约13微微克分子/分(Pmol/分),cGMP约8.5Pmol/分。血液中环核苷酸除了被细胞摄取外,还可由肾排出或被磷酸二酯酶(PDE)降解。放射免疫法测出血与尿cAMP含量分别为24.1±6.6Pmol/ml和2.3±0.5Pmol/μg肌酐;cGMP则分别为9.5±5.5Pmol/ml和0.21±0.1Pmol/μg肌酐,以上数值国内外基本相接近。但体液与组织中环核苷酸浓度受取样条件如空腹、运动、时间与饮食等因素影响,故仅能作一对照值,供参考。本文试以基础与临床相结合的原则,从几个侧面概述环核苷酸的生理与临床意义,或许对指导实践会带来裨益。一、腺苷环化酶的活化原理与激素不应症儿茶酚胺与肽类激素要通过cAMP发挥激素的细胞效应,这里cAMP起着第二信使作用。新的概念认为,腺苷酸环化酶复合物由受体、调节蛋白(G—蛋白)又称偶联因素和酶催化单位三部分组成。调节蛋白能与鸟苷酸结合,鸟苷酸是腺苷酸环化酶活化所绝对需要的物质。当激素与受体结合后,原来与调节蛋白结 Cyclic nucleotides (cAMP, cGMP) are the intermediates of catecholamines and peptide hormones in the body and the effects of various drugs. A variety of physiological effects in the body are involved in these two important regulatory substances. Under normal conditions, intracellular cAMP is 1 to 2 orders of magnitude higher than cGMP, with concentrations of 10 -7 to 10 -6 and 10 -9 -10 -8 respectively . It can enter the body fluid through the cell membrane, and extracellular cyclic nucleotides can be taken up by the cells, rapid bi-directional intracellular and extracellular flow. Human cAMP production rate of about 13 picograms per minute (Pmol / min), cGMP about 8.5Pmol / min. In addition to being taken up by cells, cyclic nucleotides in the blood can also be excreted by the kidneys or degraded by phosphodiesterase (PDE). Radioimmunoassay measured blood and urine cAMP levels were 24.1 ± 6.6Pmol / ml and 2.3 ± 0.5Pmol / μg creatinine; cGMP were 9.5 ± 5.5Pmol / ml and 0.21 ± 0.1Pmol / μg creatinine, the above values ​​at home and abroad basic Close to However, the concentration of nucleotides in the body fluids and tissues is influenced by the sampling conditions such as fasting, exercise, time and diet, so only a control value can be used for reference. This article tries to summarize the physiological and clinical significance of cyclic nucleotides from several aspects based on the principle of combination of basic and clinical, which may bring benefits to the guiding practice. First, adenosine cyclase activation principle and the hormone should not be symptoms of catecholamines and peptide hormones to exert hormonal cellular effects through cAMP, where cAMP plays a second messenger role. The new concept that the adenylate cyclase complex by the receptor, regulatory protein (G-protein), also known as coupling factor and enzyme catalytic unit of three parts. Regulatory proteins bind to guanylic acid, which is absolutely required for adenylate cyclase activation. When the hormone and receptor binding, the original and regulatory protein junction