Johannsson I, Ryberg M
Department of Cariology, University of Umeå, Sweden.
Arch Oral Biol. 1991;36(8):591-4. doi: 10.1016/0003-9969(91)90109-8.
The effects of moderate protein deficiency on the number and dissociation constant of beta-adrenergic receptors were investigated. One group of adult rats was fed a protein-deficient diet (5% protein), a control group was given a similar diet with 20% protein, and a third group was fed a standard pellet diet. After 21 days, the salivary glands were removed and the cell membranes were isolated. The binding of [3H]-dihydroalprenolol to cell membranes was measured, with or without the presence of timolol, a potent beta-adrenoceptor antagonist. The rats fed the 5% protein diet had fewer beta-adrenoceptors in both the parotid and the submandibular glands than did the 20% protein group, which did not differ from the standard pellet group. The dissociation constant was not affected by protein deficiency. The rats fed the 5% protein diet had a significantly lower gain in body weight, less heavy submandibular glands but heavier parotids than the rats fed 20% protein. Thus the cellular conditions for protein secretion in the salivary glands are impaired during moderate protein deficiency in the adult rat.
研究了中度蛋白质缺乏对β-肾上腺素能受体数量和解离常数的影响。一组成年大鼠喂食蛋白质缺乏饮食（5%蛋白质），对照组给予含20%蛋白质的类似饮食，第三组喂食标准颗粒饲料。21天后，取出唾液腺并分离细胞膜。测量了[3H]-二氢心得静与细胞膜的结合，无论是否存在强效β-肾上腺素能受体拮抗剂噻吗洛尔。喂食5%蛋白质饮食的大鼠腮腺和颌下腺中的β-肾上腺素能受体均少于喂食20%蛋白质的组，而后者与标准颗粒饲料组无差异。解离常数不受蛋白质缺乏的影响。与喂食20%蛋白质的大鼠相比，喂食5%蛋白质饮食的大鼠体重增加明显更低，颌下腺更轻但腮腺更重。因此，成年大鼠中度蛋白质缺乏期间，唾液腺中蛋白质分泌的细胞条件受损。
