Effects of Zinc Supplementation on Some Hematological Parameters of Spontaneously Hypertensive Rats

The present study was undertaken to determine influence of dietary supplements of Zn containing diet (50 or 155 or 250 mg Zn/kg lab chow) on the hematological parameters of spontaneously hypertensive rats (SHR). Male SHR (n=92) and their normotensive ancestors, Wistar-Kyoto rats (WKY, n=89), were divided into 6 groups on different diet: WKY – G1-50 mg Zn/kg laboratory chow (control), G2-155 mg Zn/kg, G3-250 mg Zn/kg and SHR – G4-50 mg Zn/kg (control), G5-155 mg Zn/kg, G6-250 mg Zn/kg. The diets started at the beginning of the development of hypertension (2 months after birth) and the animals were fed for 8 weeks. At the end of the study, blood sample was taken from each animal in all groups and a complete blood count was performed. There are no statistically significant differences in the studied parameters between rats of the WKY and SHR lines. RBC and Hb were lower (p<0.05) in groups with zinc supplementation – G3 and G6, however, MCV, MCH and MCHC were higher (p<0.05) in this groups. A decreased hematocrit was found in supplemented groups (p<0.05) and the platelets count increased significantly (p=0.001). Our findings suggest that zinc supplementation is a factor, decreasing erythrocytes and hematocrit, and increasing the platelets count in the both rat's strains.