老化抑制阿片肽增强大鼠T淋巴细胞转化和阿片肽增强...

Ageing suppresses the enhancement of T cell mitogenesis by opioid peptides and enkephalins increase phagocytosis of murines macrophage]

The opioid peptides methionine enkephalin (M-ENK) and beta-endorphin (beta-END) (1 x 10(-5)-1 x 10(-11) mg/ml) were investigated for their effect on the PHA (1:500, 1:750 or 1:1000) induced proliferative response of old and young Wistar rat splenic lymphocytes in vitro. The different effects in young and old rats on proliferative response to PHA were determined. The results showed that MENK and beta-END significantly enhanced the proliferative response to PHA in young rats, while enhancement by M-ENK and beta-endorphin (PHA 1:750, 1:1000) was not observed in old rats. The PHA-induced proliferative response was 30%-40% lower in old rats than in young rats. Our results suggest an altered response to neuro-immunomodulation with age. The in vitro effect of ENKs on phagocytosis was also studied. The results indicated that LENK (10(-4)-10(-6) mg/ml) and MENK (10(-2)-10(-4) mg/ml) could stimulate the phagocytosis of peritoneal macrophages from Balb/c mice.