Histological and Biochemical study of The protective effect of subcurative dose of doxycycline on streptozotocin treated adrenal gland in adult Male Albino Rats

The adrenal gland is a major endocrine gland involved in different physiological functions. Streptozotocin (STZ) exhibits severe degeneration within the cells, with subsequent alteration of adrenal gland structure and function. Objectives: Investigate whether doxycycline at sub-antimicrobial concentrations could improve the damaging effect of streptozotocin on the adrenal gland. Material and Methods: Three animal groups (10 rats each) were used. Group A was taken as control. Group B was given 37mg/kg STZ. Group C was given 20mg doxycycline for a month then they received streptozotocin as the second group. Results: STZ-induced diabetes resulted in a significant increase in serum glucose, corticosterone levels, inflammatory and oxidative stress biomarkers. The cells of both adrenal cortex and medulla appeared disorganized. Their nuclei appeared pyknotic with vacuolated cytoplasm. The blood sinusoids appeared dilated and congested. A significant increase in interleukin-6 and caspase immunoreaction was also detected. Administration of doxycycline prior to STZ-induction revealed regression of these changes. Conclusion: Administration of doxycycline at sub-antimicrobial concentrations improved the histological and biochemical changes induced by STZ in the adrenal gland.