Genazzani A R, De Ramundo B M, Criscuolo M, De Gaetani C, Ficarra G, Genazzani A D, Petraglia F, Trentini G P
Department of Obstetrics and Gynecology, University of Modena School of Medicine, Italy.
Eur J Pharmacol. 1990 Sep 21;186(2-3):177-80. doi: 10.1016/0014-2999(90)90431-5.
With the aim of evaluating the effect of acetyl-l-carnitine (ALC) on the daily pattern of hypothalamic beta-endorphin (beta-EP), we studied the effect of chronic treatment with ALC on hypothalamic beta-EP contents after suppression of the dark-phase of the light-dark cycle in female rats. We evaluated the hypothalamic content of beta-EP immunoreactivity every 3 h for 24 h in: (1) female rats treated with ALC for 15 days; (2) female rats treated with ALC for 15 days and exposed to continuous light for 24 h. The concentration of beta-EP immunoreactivity in tissue extracts was measured by radioimmunoassay. The results demonstrate that concentrations of beta-EP immunoreactivity in the medial basal hypothalamus show a circadian rhythm, with beta-EP immunoreactivity levels being higher during the night than during the rest of the day. Exposure to continuous light for 24 h abolished the nocturnal increase in hypothalamic beta-EP immunoreactivity. Rats treated with ALC showed a daily pattern in the beta-EP content of the medial basal hypothalamus similar to that of control rats. These data emphasize the possible role of ALC in restoring or maintaining the endogenous rhythmicity of central beta-EP.
为了评估乙酰左旋肉碱（ALC）对下丘脑β-内啡肽（β-EP）日常模式的影响，我们研究了在雌性大鼠的明暗周期暗相被抑制后，ALC长期治疗对下丘脑β-EP含量的影响。我们在以下两组大鼠中每3小时评估一次下丘脑β-EP免疫反应性含量，持续24小时：（1）用ALC治疗15天的雌性大鼠；（2）用ALC治疗15天并持续光照24小时的雌性大鼠。通过放射免疫分析法测量组织提取物中β-EP免疫反应性的浓度。结果表明，内侧基底下丘脑的β-EP免疫反应性浓度呈现昼夜节律，夜间的β-EP免疫反应性水平高于一天中的其他时间。持续光照24小时消除了下丘脑β-EP免疫反应性的夜间增加。用ALC治疗的大鼠内侧基底下丘脑的β-EP含量呈现出与对照大鼠相似的日常模式。这些数据强调了ALC在恢复或维持中枢β-EP内源性节律方面的可能作用。
