Study On The Effects Of Different Levels Of Zn And Fe On Immunity Of The Old Rats

Objective: With the growth of the number of the old people, the problem of health of the elderly is becoming the hotspot of medicine field. Because of the age and some important trace elements intake deficiently, the elderly people's immunological function shows failure significantly. The nutritional status is related more to immune dysregulation than to a general age-related decrease in immune responses, so it is a convenient and efficient measure to improve the elderly people's function of the immune system. There are many reports about effects of deficiency of Zn or Fe on the immunological function of elderly people or animals, but there are not so much reports about effects of supplementation of Fe or Zn on immunity of the elderly people or animals, and also have no final conclusion. The experiment was carried out to study the effects of supplementation of different levels of Zn and Fe on the old rats' immunity by adding different density of Zn and Fe to their drinking, the red cell adhesive function, humoral immunity, function of lymphocyte and NK activity was observed. The present paper was carried out to provide reasonable supplementation of Fe and Zn for the old population and provide scientific reference for the strength of old people's immunity.Methods: 58 SD rats(age≥18 months), were divided into 9 groups randomly according to3×3 factorial experiment design, 29 males and 29 females every group: Normal group (N), middle Fe group (FeⅠ), high Fe group (FeⅡ), middle Zn group (ZnⅠ), middle Zn and middle Fe group (FeⅠZnⅠ), middle Zn and high Fe group (ZnⅠFeⅡ), high Zn group (ZnⅡ), high Zn and middle Fe group (ZnⅡFeⅠ), high Zn and high Fe group (ZnⅡFeⅡ). The trial groups supply Zn and Fe by drinking water contained different concentration of zinc sulfate and ferrous sulphate. The general status and weight were observed during feeding period. Rats were put to death at 45th day to determine the following parameters: the body weight of rat, the spleen weight and spleen index, the content of immunoglobulin G (IgG), transformation efficiency of lymphocyte of spleen, activity of natural killer cell of spleen, red blood cell C3b rosettes rate (RBC- C3bRR) and red blood cell IC rosettes rate (RBC-ICRR), Statistical analysis was performed by factorial analysis and ANOVA, with SPSS11.5.Results: 1 Effects of supplementation of Zn and Fe on the weight of old rats: Weight of N, ZnⅠ, FeⅠZnⅠ and FeⅡgroups increased during the first 30 days, and decreased after that time, other groups' weight decreased during the whole feeding period. There were no effects of different levels and interaction of Fe and Zn on the weight of the old rats (P>0.05).2 Results of multiple comparison of Zn and Fe in the old rats serum: Zn: The content of Zn in serum of ZnⅡ, ZnⅠ, ZnⅡFeⅠ groups as the first there highest groups, they had the significant difference each other, and they also had significant difference with other groups (P<0.05). The content of Zn in serum of FeⅡ and FeⅠ groups is lowest and have significant difference with other groups (P<0.05). The FeⅡ group is lower than FeⅠ (P<0.05). Fe: The content of Fe in serum of FeⅠ is higher than ZnⅠ and ZnⅡ groups (P<0.05), FeⅡ has significant difference with all groups (P<0.05) except ZnⅠFeⅡ and ZnⅡFeⅡ groups (P>.05), the group of N has no significant difference with ZnⅠ and ZnⅡ (P>0.05) and lower than other groups. The result of factorial analysis: Supplementation of Zn in different levels had independent effects on content of Zn (P<0.05) and had no effects on Fe in serum (P>.05). Supplementation of Fe in different levels had independent effects on content of Zn and Fe in serum (P<0.05). Zn and Fe have interaction effects on the content of Zn in serum (P<0.05). The results indicate that Fe inhibits Zn absorption (P<0.05), and the content of serum Zn declined with the increase of supplementation of quantity of Fe, but there was no effect of supplementation of Zn on Fe in serum.3 There were no significant effects of different level...