The effect of pinealectomy on immune parameters in different age groups inrats: results of the weekly alteration of the zinc level and the effect ofmelatonin administration on wound healing

It is generally accepted that the pineal gland is a neuroendocrine organ. S everal recent experiments have shown that the pineal gland has functional a nd anatomic connections with many organs and systems, particularly with the immune system, and, therefore, the gland is now recognised as an important immunoneuroendocrine organ both in man and animals. The present study inve stigates the effect of pinealectomy on some immune parameters including zin c pool alterations and wound healing process in different age group in rats and also investigates the effect of melatonin administration on wound heal ing in different age groups. Experiments were performed on two different ag e groups of rats (neonatal and young). We have experimentally shown the ind uction of immune depression by pinealectomy and the restorative competence of melatonin administration in the present study. The results also showed t hat the plasma zinc level was significantly reduced in the third week after the pinealectomy particularly in pinealectomised neonatal rats and the wou nd healing process affected only in pinealectomised neonatal rats but resto red to normal by melatonin administration. In view of these data, as descri bed previously, the pineal gland has a main regulatory function in immune p hysiology, but our study indicates that only neonatal immune functions are significantly affected by pinealectomy. (C) 2000 Harcourt Publishers Ltd.