Liu B, Burbach J P
Rudolf Magnus Institute for Pharmacology, University of Utrecht, The Netherlands.
Peptides. 1988 Nov-Dec;9(6):1235-40. doi: 10.1016/0196-9781(88)90187-8.
Vasopressin (VP)-converting aminopeptidase (VP-AP) activity and VP contents were measured in single rat pineal glands during the summer of two successive years. The peptidase activity decreased significantly in August. The lowest activity (+/- SEM) of 0.18 +/- 0.02 pmol.hour-1 was recorded on August 14, compared to the basal activity of 0.25 +/- 0.01 pmol.hour-1 in July and September of 1986. The change with similar percentage occurred in the same period of 1987. The specific activity of the enzyme in the crude homogenate, 15,000 g pellet and supernatant fraction of rat pineal glands, exhibited the same pattern of variations. The decrease in peptidase activity coincided with the previously reported dramatic rise in pineal VP content in early August which was confirmed in this series of experiments. Another peptidase, the so-called gamma-endorphin generating endopeptidase (gamma-EGE) activity, and beta-endorphin-related peptides in the pineal gland did not change in this period. The results show that the variations of pineal VP contents and VP-AP activity during summer are not general for other peptides and peptidases. The coincidence of opposite changes in VP content and VP-AP activity of the pineal gland may indicate a role of the peptidase activity to regulate the VP content.
在连续两年的夏季，对单个大鼠松果体中的加压素（VP）转换氨肽酶（VP - AP）活性和VP含量进行了测定。8月份肽酶活性显著下降。1986年8月14日记录到最低活性（±标准误）为0.18±0.02 pmol·小时⁻¹，而7月和9月的基础活性为0.25±0.01 pmol·小时⁻¹。1987年同期出现了类似百分比的变化。大鼠松果体粗匀浆、15,000 g沉淀和上清液组分中该酶的比活性呈现相同的变化模式。肽酶活性的下降与先前报道的8月初松果体VP含量的急剧上升相吻合，本系列实验证实了这一点。松果体中的另一种肽酶，即所谓的γ-内啡肽生成内肽酶（γ - EGE）活性以及β-内啡肽相关肽在此期间没有变化。结果表明，夏季松果体VP含量和VP - AP活性的变化并非其他肽和肽酶所共有。松果体VP含量和VP - AP活性的相反变化同时出现，这可能表明肽酶活性在调节VP含量方面发挥了作用。
