Objective: To evaluate the protective effect of zinc on histomorphometry of femur of Sprague Dawley rats under
high salt diet.
Study Design: Analytical randomized control trial.
Place and Duration of Study: The studied was carried out at Islamic International Medical College, Rawalpindi,
with the collaboration of National Institute of Health; Islamabad. The study spanned over a period of six months,
from Sep 2015 to Mar 2016.
Material and Methods: Forty five female Sprague Dawley rats, 10-12 weeks old were used in the study. The rats
were randomly divided into 3 groups. Group-A rats were fed high salt diet (8% NaCl) and group B rats were
given high salt diet augmented with zinc (50mg/kg/day) for eight weeks, however, the diet of control group was
not modified. Rats were dissected and left femora were removed. Decalcification was performed. Tissue from
proximal femur was obtained to study the trabecular structure and collagen staining while midshaft of femur was
transversely sectioned to measure the medullary cavity diameter. Processing was done to obtain five micrometer
(Î¼m) thick sections. Tissues were stained with haematoxylin and eosin (H&E) and Masson’s Trichrome for
histological parameters. Comparison was done amongst all groups.
Results: Obvious histological variations were observed in experimental groups. These changes were of more
severity in rats of group-A who took high salt diet as compared to group B who received zinc supplementation in
addition to salt.
Conclusion: High salt diet exerted harmful effects on bones due to increased sodium chloride induced
hypercalciuria leading to bone loss. Zinc is valuable in ameliorating the detrimental effects of salt on bones by
enhancing osteoblast activity and inhibiting bone resorbing cells.
Hypercalciuria, Osteoblast, Salt, Zinc.