Combined effects of moderate feed restriction and acute inflammation on rat serum transthyretin

Abstract The combined effects of moderate feed restriction and acute inflammation on serum transthyretin (TTR) levels were studied in five groups of 4-week-old male Wistar rats fed a 18% protein diet. Two groups were fed ad libitum: the control (C) and turpentine (T) groups while 2 others were given the diet in restricted amounts: the restricted (R) and restricted and turpentine-injected (RT) groups. After 18 days on the experimental diets, groups T and RT were injected with turpentine (0.5 ml/100g body weight). A fifth group, previously fed ad libitum was then pair-fed to group T for 48h (group PF). Groups T and RT were killed 48h following turpentine administration together with group R while group PF was killed 24h later. Half of the control group was killed with the four former groups and half with the latter. Orosomucoid levels were dramatically enhanced in the groups T and RT and were not affected by food restriction. Transferrin levels were decreased in group R and only very slightly increased by acute inflammation. TTR concentration fell by 65% in group T; twenty-one percent of this decrease resulted from the associated reduction in food intake. The specific effect of inflammation on TTR level was similar when calculated from the difference between the values obtained in groups PF and T on the one hand and between groups R and RT on the other hand. The results suggest that when moderate feed restriction and acute inflammation are associated, total decrease in serum TTR levels is the sum of the individual drops induced by the nutritional and the inflammatory insults.