Schedl H P, Wilson H D, Horst R L
Medical Service, Veterans Administration Medical Center, Iowa City, Iowa.
Hypertension. 1988 Sep;12(3):310-6. doi: 10.1161/01.hyp.12.3.310.
Conflicting results have been published by different laboratories comparing the rate of intestinal calcium transport and concentration of circulating 1,25-dihydroxyvitamin D (1,25-[OH]2D) in the spontaneously hypertensive rat (SHR) and control Wistar-Kyoto rat (WKY): They have been reported to be greater, the same, or lower in the SHR than in the WKY. We tested the possibility that the conflicting results might be breeder-related by measuring 1) the rate of intestinal mucosal calcium transport, 2) the concentration of circulating 25-hydroxyvitamin D (25-OH-D) and 1,25-(OH)2D, and 3) the concentration of intestinal mucosal receptor for 1,25-(OH)2D in the two strains of animals from three different breeders. Sodium and water transport were also measured because of their relevance to hypertension. Blood pressure was always higher and calcium, as well as mean sodium and water transport, was always lower in the SHR than in the WKY. The concentration of 1,25-(OH)2D was the same, higher, or lower in the SHR than in the WKY and was age- and breeder-dependent. Mean mucosal 1,25-(OH)2D receptor concentration was higher in the SHR and was variable, depending on breeder. We conclude that 1) the rate of calcium transport is lower in the SHR than in the WKY and independent of breeder and concentration of 1,25-(OH)2D in serum, 2) the variability in 1,25-(OH)2D concentration among investigators may be breeder-dependent, and 3) the higher receptor concentration in the intestinal mucosa of the SHR could be a compensatory response to the decreased rate of calcium transport. These differences in calcium and sodium transport may be an expression in the enterocyte of factors etiological for hypertension.
不同实验室发表了相互矛盾的结果，这些结果比较了自发性高血压大鼠（SHR）和对照Wistar-Kyoto大鼠（WKY）的肠道钙转运速率以及循环中的1,25-二羟基维生素D（1,25-[OH]2D）浓度：据报道，SHR中的这些指标比WKY中的更高、相同或更低。我们通过测量以下指标来测试相互矛盾的结果可能与繁殖者相关的可能性：1）肠黏膜钙转运速率，2）循环中的25-羟基维生素D（25-OH-D）和1,25-(OH)2D浓度，以及3）来自三个不同繁殖者的这两种动物品系的肠黏膜1,25-(OH)2D受体浓度。还测量了钠和水的转运，因为它们与高血压有关。SHR的血压总是高于WKY，而钙以及平均钠和水的转运总是低于WKY。SHR中1,25-(OH)2D的浓度比WKY中的更高、相同或更低，并且取决于年龄和繁殖者。SHR中平均黏膜1,25-(OH)2D受体浓度更高，并且因繁殖者而异。我们得出以下结论：1）SHR中的钙转运速率低于WKY，且与繁殖者和血清中1,25-(OH)2D的浓度无关；2）研究者之间1,25-(OH)2D浓度的差异可能取决于繁殖者；3）SHR肠黏膜中较高的受体浓度可能是对钙转运速率降低的一种代偿反应。钙和钠转运的这些差异可能是高血压病因学因素在肠细胞中的一种表现。
