Effect of pinealectomy on immune parameters in rats with Staphylococcus aureus infection

It is generally accepted that the pineal gland is a neuroendocrine organ. Several recent experiments have shown that the pineal gland has functional and anatomical connections, particularly with the immune system, and therefore the gland is now recognized as an important immunoneuroendocrine organ in both man and animals. The present study investigates the effect of pinealectomy on some immune parameters, including hematological alterations, and the response of the brain tissue against infection caused by Staphylococcus aureus. Experiments were performed on two different age groups of rats (neonatal and young). The results showed a significant reduction of the plasma zinc level in the third week following pinealectomy, impairment of the hematological parameters including lymphocyte, erythrocyte, and leucocyte, and the deficiency of the brain response to the infective agent, particularly in pinealectomized neonatal rats. In view of these data and as described previously, the pineal gland has a main regulatory function in immune physiology, but our study indicates that only neonatal immune functions are significantly affected by pinealectomy.