Metabolic study on Ca-deficient rats using a multitracer

Abstract

By applying a multitracer technique to Ca-deficient and normal rats, the metabolism in their bodies was examined. A multitracer solution was prepared from a gold target irradiated with a heavy-ion beam of 135 MeV/nucleon. Three male rats weighing 105 g on average fed with Ca- and vitamin D-deficient diet for three weeks were used as specimens, while three six-week-old male normal ones weighing 190 g on average were used as reference rats. The Ca content in blood plasma was found to be 3.4 +/- 0.2 mg/dl for the former and 10.8 +/- 0.2mg/dl for the latter. The changes in Be, Ca, V, Mn, Zn, As, Se, Rb, Sr and Ba in organs of these live rats was examined using the multitracer. The amounts of Rb, V and Mn found in the liver, kidney, spleen, brain, testicle, intestine and bone of the two rat groups were compared. Regarding Rb, no difference was found between the two rat groups. In the Ca-deficient rats, the amount of Mn taken into their liver decreased but the amount of V taken into their testicle and bone increased. The decrease of Mn taken into their liver suggests that an enzyme such as pyruvate carboxylase was influenced by Ca deficiency.

Ca欠乏ラットと正常ラットにマルチトレーサを用いて、生体内の物質代謝を調べた。135MeV/核子に加速した重イオンで金標的を照射して、マルチトレーサ溶液を作製した。カルシウムとビタミンDが欠乏した飼料で3週間飼育した平均105gの3匹のオスを試料ラットとし、平均190gの3匹の正常な6週齢のオスを参照ラットとして用いた。血漿中のCa濃度は前者で3.4±0.2mg/デシリットル、後者で10.8±0.2mg/デシリットルであった。Be、Ca、V、Mn、Zn、As、Se、Rb、SrおよびBaの各元素の生体内各器官における挙動をマルチトレーサで調べた。肝臓、腎臓、脾臓、脳、こう丸、腸、骨でのRb、V、Mnの量を比較した。Rbには差が見られなかった。Ca欠乏ラットについては、肝臓ではMn取込み量が減少し、骨とこう丸ではV取込み量が増加した。Mnの肝臓における取込み量の減少は、酵素触媒たとえばカルボキシル・ピルビン酸がCaの欠乏によって影響を受けること示している。