Zum Einfluß Einer Hinsichtlich Qualität und Quantität Unterschiedlichen Proteinversorgung auf Wachstum und Wachstumshormon im Serum Entwöhnter Ratten

Abstract

A two-factorially experiment was done over a period of 42 days using 32 male, weaned Sprague-Dawley rats in order to study the effect of insufficient protein supplementation, with regard to quantity and quality (13% protein in comparison to 18%, and an essential amino acid index of 64 in comparison to 92%, resp.), on weight development and serum growth hormone concentration. Qualitative protein deficiency had a greater adverse effect on weight development and feed utilization than did quantitative protein deficiency. Both test factors combined brought about the lowest body weight and poorest feed utilization. A lowered hematocrit value occurred only after quantitative protein deficiency. The serum urea concentration was elevated after protein deficiency due to poor quality protein; the serum protein concentration tended toward reduction in both the case of qualitative as well as in the case of qualitative-quantitative protein deficiency. After providing the animals poor quality protein, growth hormone levels in serum were reduced, whereas the concurrence of both factors of protein deficiency caused the growth hormone concentration in serum to rise to a value 4.2-fold of the control value.

Influence of Alimentary Zinc Deficiency on the Concentration of Growth Hormone (GH), Insulin-Like Growth Factor I (IGF-I) and Insulin in the Serum of Force-Fed Rats

“…This means that the reduced GH concentrations in the serum of the Zn-deficient and the pair-fed control rats is the result of the reduced feed intake and the associated protein and energy depletion rather than being caused by Zn deficiency per se. Other authors also reported a marked influence of feed intake {Phillips and Young 1976; Ghavami-Maibodi, Collipp, Castro-Magana, Stewart and Chen 1983;Nishi, Hatano, Aihara, Fujie and Kihara 1989) or of energy and protein deficiency (Kirchgefiner, Jacob-Hammermann and Roth 1987;Jacob-Hammermann, Kirchgefiner and Roth 1987) on the GH concentration in the serum. In situations of marginal Zn depletion, when the rats' feed intake was unaffected or only slightly impaired (Kirchgefiner and Roth 1985), while the serum Zn concentrations were nonetheless significantly reduced, GH concentrations in the serum of the Zn-deficient rats were also distinctly reduced compared to the pair-fed control rats.…”