Effect of phytohormones on tissue hexokinase and on some blood components in wistar rats

Dietary phytohormones may influence the metabolic processes in animal cells. To determine the effect of the plant growth regulators 28-homobrassinolide, gibberellic acid and kinetin on the tissue hexokinase and some blood components in male rats. Methods: 50μg 28-bomobrassinolide, gibberellic acid and kinetin (Normal saline served as control) was injected intradermally. Hexokinase activity in several tissues and blood level of glucose, hemoglobin and cholesterol were determined 2 h after injection. 28-homobrassinolide increased hexokinase activity in all tissues studied, and reduced blood glucose level but increased hemoglobin and cholesterol level. Gibberellic acid increased hexokinase activity in liver, but decreased it in other tissues and increased significantly blood cholesterol and slightly glucose and hemoglobin levels. Kinetin decreased hexokinase activity significantly in liver and kidney, but not significantly in other tissues, and reduced slightly glucose and hemoglobin levels and reduced significantly serum cholesterol level. This study indicated that treatment of rat with 28-homobrassinolide significantly increased hexokinase activity in liver, heart and kidney whereas gibberellic acid increased hexokinase activity only in the liver, and Kinetin decreased hexokinase activity in most tissues. Decreased hexokinase activity was observed due to kinetin and gibberellic acid treatment, except for gibberellic acid in the liver tissue, and was indicative of the fact that kinetin and gibberellic acid acted as negative modulators of this enzyme in the rat tissues. Thus, three different phytohormones possessed different degrees of effect in the animal cells. Keywords: Hexokinase; Hemoglobin; Gibberellic acid; 28-homobrassinolide; Kinetin.