Presch I, Birnbacher R, Herkner K, Lubec G
University of Vienna, Dpt of Pediatrics, Austria.
Life Sci. 1997;60(7):479-84. doi: 10.1016/s0024-3205(96)00678-9.
Although the regulatory activity of steroid hormones on amino acid metabolism has been described, no information is published on the effect of ovariectomy. We studied the influence of ovariectomy in Wistar rats determining the amino acids such as phenylalanine and tyrosine in liver, kidney and urine. 32 animals were used in the study, 12 animals were sham operated, 9 animals were ovariectomized and 11 rats were ovariectomized and supplemented with estradiol. No quantitative changes were detected comparing liver and kidney phenylalanine and tyrosine between the groups. The phenylalanine/tyrosine ratio in liver and urine of ovariectomized rats showed a significant decrease of the quotient, which was restored by estradiol replacement, whereas the ratio was unaffected in the kidney. Tyrosine hydroxylase was in liver (0.04 +/- 0.04 U/min), kidney (0.4 +/- 0.04 U/min) in the sham operated rats; liver (0.06 +/- 0.02 U/min), kidney (0.3 +/- 0.2 U/min) in ovariectomized and liver (0.07 +/- 0.055 U/min), kidney (0.4 +/- 0.1 U/min) in the ovariectomized with estradiol replacement. Tyrosine aminotransferase was in liver (0.004 +/- 0.002 U/h), kidney (0.01 +/- 0.002 U/h) in the sham operated panel; liver (0.005 +/- 0.001 U/h), kidney (0.01 +/- 0.004 U/h) in the ovariectomized and liver (0.005 +/- 0.002 U/h) and kidney (0.012 +/- 0.007 U/h) in the ovariectomized with estradiol supplementation. Phenylalanine hydroxylase was in liver (0.12 +/- 0.07 U/min), kidney (0.5 +/- 0.3 U/min) in the sham operated group; liver (0.19 + 0.16 U/min), kidney (0.5 +/- 0.2 U/min) in the ovariectomized and liver (0.15 +/- 0.09 U/min), kidney (0.4 +/- 0.2 U/min) in the ovariectomized rats with estradiol replacement. No significant difference in the enzyme activities between the groups was found. The impairment of the phenylalanine/tyrosine ratio in liver could be assigned to an endocrine control of amino acid uptake and/or transport, in the urine by different pools, proteolytic and synthetic enzyme activites, filtration/reabsorptioneffects.
尽管已经描述了类固醇激素对氨基酸代谢的调节作用，但关于卵巢切除术的影响尚无相关信息发表。我们通过测定Wistar大鼠肝脏、肾脏和尿液中的苯丙氨酸和酪氨酸等氨基酸，研究了卵巢切除术的影响。本研究使用了32只动物，其中12只进行假手术，9只进行卵巢切除术，11只进行卵巢切除术后补充雌二醇。比较各组肝脏和肾脏中的苯丙氨酸和酪氨酸，未检测到定量变化。卵巢切除大鼠肝脏和尿液中的苯丙氨酸/酪氨酸比值显示该商数显著降低，通过补充雌二醇可使其恢复，而该比值在肾脏中未受影响。假手术大鼠肝脏中酪氨酸羟化酶活性为(0.04±0.04 U/min)，肾脏中为(0.4±0.04 U/min)；卵巢切除大鼠肝脏中为(0.06±0.02 U/min)，肾脏中为(0.3±0.2 U/min)；卵巢切除术后补充雌二醇的大鼠肝脏中为(0.07±0.055 U/min)，肾脏中为(0.4±0.1 U/min)。假手术组肝脏中酪氨酸转氨酶活性为(0.004±0.002 U/h)，肾脏中为(0.01±0.002 U/h)；卵巢切除大鼠肝脏中为(0.005±0.001 U/h)，肾脏中为(0.01±0.004 U/h)；卵巢切除术后补充雌二醇的大鼠肝脏中为(0.005±0.002 U/h)，肾脏中为(0.012±0.007 U/h)。苯丙氨酸羟化酶活性在假手术组肝脏中为(0.12±0.07 U/min)，肾脏中为(0.5±0.3 U/min)；卵巢切除大鼠肝脏中为(0.19 + 0.16 U/min)，肾脏中为(0.5±0.2 U/min)；卵巢切除术后补充雌二醇的大鼠肝脏中为(0.15±0.09 U/min)，肾脏中为(0.4±0.2 U/min)。各组酶活性未发现显著差异。肝脏中苯丙氨酸/酪氨酸比值的损害可能归因于氨基酸摄取和/或转运的内分泌控制、尿液中不同池的情况、蛋白水解和合成酶活性、滤过/重吸收效应。
