The effect of pinealectomy and foetal pineal transplantation on collagen ageing in rats

Summary Recent progress in pineal research emphasized the importance of this circumventricular organ in the phenomenon of ageing as well. The present study was undertaken to elucidate the effects of pineal gland on collagen ageing by spectrofluorometrically measuring collagen-cross-link bound fluorescein. Experiments were performed on three different age groups of rats (3–4 weeks, 8–10 weeks, 15 and more weeks). Fluorescein values were found to increase causally by age in the control group. Eight weeks after sham operation of all the groups fluorescein level increments were shown to be parallel with the values of normal physiological ageing values. In experimental groups; in 3–5 weeks old rats pinealectomy produced a significant premature collagen ageing and this was found to be completely reversed by foetal pineal gland transplantation, but the reversal was limited to a sham operation level. On the other hand although a premature collagen ageing was found to be induced 8 weeks after pinealectomy in 8–10 weeks old rats with a statistical significance both within subject values and between sham operation and pinealectomy, foetal pineal gland transplantation was found not to reverse the premature ageing induced by pinealectomy. In 15 weeks old and older groups of rats, pinealectomy was found to facilitate the intrinsic ageing phenomenon of collagen with statistical significance again both within subject values and between sham operation and pinealectomy. Foetal pineal gland transplantation was not performed in this age group of rats. On interpretation of the data of pinealectomy against sham operation for all the age groups, the maximum degree of percentage increase in collagen-cross-link bound fluorescein was found in 3–5 weeks old rats (%218). The percentage increase in fluorescein values was found to be %170 and %126 in 8–10 weeks old and 15 weeks old and older rat groups, respectively. Consequently, we have experimentally shown the induction of collagen ageing by pinealectomy and the restorative competence of foetal pineal gland transplantation in the present study. The results seem to be impressive and details of the ageing process are the subject of further research.