Morphological changes in spleen after dietary zinc deficiency and supplementation in Wistar rats.

Background: Study was conducted to determine the effect of dietary zinc deficiency and supplementation on the spleen morphology.

Methods: Pre-pubertal Wistar rats (40-50 g) were divided into two groups with 6 sub-groups each viz. zinc control (ZC, 100 μg/g zinc diet), pair fed (PF, 100 μg/g zinc diet), zinc deficient (ZD, <1 μg/g zinc diet, zinc supplementation control (ZCS), zinc supplementation pair-fed (PFS) and zinc supplementation deficient (ZDS, 100 μg/g zinc control diet). Experiments were set for 2- and 4-weeks followed by 4 weeks of zinc supplementation.

Results: In the present study body weight and BMI decreased significantly along with incidence of splenomegaly as typified by the increased splenic index in deficient groups compared with that of respective control groups. Histopathological changes such as disorganization of red pulp, several infiltered lymphocytes, vacuolization, loss of cellularity, karyolysis, dissolution of matrix, indistinct differentiation between red and white pulp were evident in spleen of 2ZD and 4ZD group animals. Degeneration was more severe after 4 weeks of zinc deficiency as giant cells formation and hypertrophy were also evident.

Conclusion: The findings revealed that zinc deficiency causes growth retardation and splenomegaly. Degenerative and atrophic changes in rat spleen suggest reduced cellular defense potential which will have a direct effect on immunity. Zinc supplementation may prove to be beneficial as there were varying degrees of cellular recovery after cessation of zinc deficiency.