Zemel S, Millan M A, Feuillan P, Aguilera G
Section on Endocrine Physiology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892.
J Clin Endocrinol Metab. 1990 Oct;71(4):1003-7. doi: 10.1210/jcem-71-4-1003.
The binding characteristics and distribution of angiotensin-II (AII) receptors were studied in Cynomolgus monkey fetuses and one second trimester human fetus. In contrast to the adult monkey, in which binding was confined to the adrenal gland, kidney, and smooth muscle, autoradiographic studies in the monkey fetus revealed the presence of high density binding in mesenchymal tissue throughout the body, especially in skeletal muscle and dermis. In the kidney at 11 weeks, binding was mainly associated with connective tissue surrounding primitive nephrons, while at 17 weeks, binding distribution was similar to that in the adult primate kidney, being confined to the glomeruli and smooth muscle of blood vessels, with low binding in the tubules. In fetal monkey adrenal, binding was high in the medulla and connective tissue of the capsule, and low in the zona glomerulosa, while in the adult, binding was high in the zona glomerulosa and medulla. In membrane preparations from fetal monkey skin and skeletal muscle, binding was specific for AII analogs, but in contrast to the adult adrenal, it was not affected by guanyl nucleotides. Scatchard analysis showed a single class of sites with a Kd of 0.6 +/- 0.1 nM and a capacity of 3060 +/- 8.3 fmol/mg, higher than that of the adult adrenal glomerulosa (605 +/- 30 fmol/mg). Specific binding for AII analogs was also present in human fetal skin and skeletal muscle membranes, where Scatchard analysis indicated a Kd of 0.8 nM and a binding capacity of 640 fmol/mg. The transient expression of abundant AII receptors during the phase of rapid growth in the fetus in conjunction with the known effects of AII on cellular growth suggest a role for AII during fetal development in the primate.
在食蟹猴胎儿和一名孕中期人类胎儿中研究了血管紧张素 II（AII）受体的结合特性和分布。与成年猴不同，成年猴的结合局限于肾上腺、肾脏和平滑肌，而对猴胎儿的放射自显影研究显示，全身间充质组织中存在高密度结合，尤其是骨骼肌和真皮。在11周时的肾脏中，结合主要与原始肾单位周围的结缔组织相关，而在17周时，结合分布与成年灵长类动物肾脏相似，局限于肾小球和血管平滑肌，肾小管中结合较低。在胎儿猴肾上腺中，髓质和被膜结缔组织中的结合较高，球状带中的结合较低，而在成年猴中，球状带和髓质中的结合较高。在胎儿猴皮肤和骨骼肌的膜制剂中，结合对 AII 类似物具有特异性，但与成年肾上腺不同，它不受鸟苷酸的影响。Scatchard 分析显示有一类单一的结合位点，Kd 为 0.6±0.1 nM，容量为 3060±8.3 fmol/mg，高于成年肾上腺球状带（605±30 fmol/mg）。在人类胎儿皮肤和骨骼肌膜中也存在对 AII 类似物的特异性结合，Scatchard 分析表明 Kd 为 0.8 nM，结合容量为 640 fmol/mg。胎儿快速生长阶段丰富的 AII 受体的短暂表达，连同 AII 对细胞生长的已知作用，表明 AII 在灵长类动物胎儿发育过程中发挥作用。
