Parini A, Coupry I, Laude D, Diop L, Vincent M, Sassard J, Dausse J P
Département de Pharmacologie, INSERM U7/UA 318 CNRS, Hopital Necker, Paris, France.
Am J Hypertens. 1988 Apr;1(2):140-5. doi: 10.1093/ajh/1.2.140.
Sympathetic activity modulates the blood pressure in part by activation of cardiac and renal adrenergic receptors. Thus an alteration of tissue noradrenaline content and/or adrenergic receptors in heart and kidney might be involved in the pathogenesis of hypertension. In order to verify this possibility, we studied tissue noradrenaline content and alpha and beta adrenergic receptors in the heart and kidney of Lyon hypertensive (LH), normotensive (LN), and low-pressure (LL) rats. Density and affinity of receptors were determined using the specific radioligands [3H]-prazosin (alpha 1), [3H]-rauwolscine (alpha 2), and [3H]-dihydroalprenolol (beta) in prehypertensive (5-week-old) and hypertensive (21-week-old) rats. In the prehypertensive period, no differences concerning renal and cardiac noradrenaline content and adrenergic receptor densities and affinities were observed. In the hypertensive period, an age-related decrease of renal alpha 1 and beta receptors was observed in LN and LL (P less than 0.01) but not in LH rats. Consequently, at this time, density of renal alpha 1 and beta receptors was higher in LH than in LN and LL (P less than 0.01). In contrast, the density and affinity of renal alpha 2 and cardiac alpha 1 and beta receptors and tissue noradrenaline content were similar in the three rat strains. Because renal alpha 1 and beta receptors mediate various functions involved in the control of blood pressure such as tubular sodium reabsorption, renin secretion, and glomerular filtration, the different density of these receptors in LH rats might be involved in the development or maintenance of hypertension.
交感神经活动部分通过激活心脏和肾脏的肾上腺素能受体来调节血压。因此，心脏和肾脏组织中去甲肾上腺素含量和/或肾上腺素能受体的改变可能参与了高血压的发病机制。为了验证这种可能性，我们研究了里昂高血压（LH）、正常血压（LN）和低血压（LL）大鼠心脏和肾脏中的组织去甲肾上腺素含量以及α和β肾上腺素能受体。在高血压前期（5周龄）和高血压期（21周龄）的大鼠中，使用特异性放射性配体[3H]-哌唑嗪（α1）、[3H]-育亨宾（α2）和[3H]-二氢心得静（β）来测定受体的密度和亲和力。在高血压前期，未观察到肾脏和心脏去甲肾上腺素含量以及肾上腺素能受体密度和亲和力的差异。在高血压期，LN和LL大鼠的肾脏α1和β受体出现与年龄相关的减少（P<0.01），但LH大鼠未出现这种情况。因此，此时LH大鼠肾脏α1和β受体的密度高于LN和LL大鼠（P<0.01）。相比之下，三种大鼠品系的肾脏α2、心脏α1和β受体的密度和亲和力以及组织去甲肾上腺素含量相似。由于肾脏α1和β受体介导了血压控制中涉及的各种功能，如肾小管钠重吸收、肾素分泌和肾小球滤过，LH大鼠中这些受体的不同密度可能参与了高血压的发生或维持。
