Nutritionally-induced elevation of serum proteinase inhibitors and reduced 3-methylhistidine excretion in the rat.
One group of growing rats was fed ad libitum a low protein and energy diet (PER). A second group was fed a low protein diet (PR). Both these groups showed a gain in weight below that of the control group. A third group was fed a very low protein and energy diet (VPER). A weight gain could also be observed in this group but this gain was lower than those observed in the first two groups. A fourth group that was on a very low protein diet (VPR) gained almost no weight. After 6 weeks a significant reduction in 3-methylhistidine excretion in urine was observed in all the experimental animals with lowest values found in the VPER and VPR groups. Total serum protein levels declined to a certain extent because of the protein and energy restrictions but albumin and transferrin remained largely unaffected. Significantly lower serum concentrations were found only in the VPR group. The rat serum proteinase inhibitors alpha 1-macroglobulin and alpha 1-inhibitor3 decreased when protein and energy were restricted and alpha 1-proteinase inhibitor decreased only in the VPER and VPR groups. alpha 2-macroglobulin and alpha 1-cysteine proteinase inhibitor concentrations increased considerably in the serum of the experimental groups. The results are discussed in relation to the probable role of the latter two inhibitors in the adaptation process when protein and energy were restricted and compared to similar observations recorded in man.
Sarisnerand
V
V
Institute of Social Medicine, Free University, Berlin.
Schelp
F P
FP
Hiller
H H
HH
Gauthier
F
F
Siegert
M
M
Reutter
W
W
D000818:Animals; D001798:Blood Proteins / Q000378:metabolism*; D004038:Diet, Reducing; D004734:Energy Metabolism; D008297:Male; D008657:Metabolic Clearance Rate; D008762:Methylhistidines / Q000652:urine*; D009751:Nutritional Requirements; D011480:Protease Inhibitors / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012709:Serum Albumin / Q000378:metabolism; D014168:Transferrin / Q000378:metabolism; D000511:alpha-Macroglobulins / Q000378:metabolism
D001798:Blood Proteins; D008762:Methylhistidines; D011480:Protease Inhibitors; D012709:Serum Albumin; D014168:Transferrin; D000511:alpha-Macroglobulins; C028118:3-methylhistidine