Elucidation of physiological finction of anandamide, an endogenous marijuana-like substance, in mammals

n -酰基乙醇胺（NAEs）构成了一个庞大而多样的信号脂类，包括内源性大麻素anandamide。人们普遍认为，在哺乳动物组织中，所有NAEs主要是通过一种膜相关磷脂酶D（通常缩写为NAPE-PLD）的催化，从相应的n -酰基磷脂酰乙醇胺（nape）中释放出来的。最近，我们发现NAPE-PLD是参与nas生物合成的候选酶。为了了解anandamide和其他生物活性NAEs在哺乳动物中的生理和病理生理意义，我们制造了靶向破坏NAPE-PLD基因（NAPE-PLD-1）的小鼠并对其进行了表征。(1)用Cre/loxP系统去除NAPE-PLD基因外显子3。(2) NAPE-PLD-1-按预期孟德尔频率出生，存活健康，与野生型仔鼠相比，笼内行为无明显差异。(3) RT-PCR和抗NAPE-PLD抗体Western blotting证实NAPE-PLD组织中不存在NAPE-PLD mRNA和蛋白。(4)与野生型组织相比，以n -棕榈酰pe为底物的NAPE- pld活性显著降低。(5)在nape - pli脑中观察到饱和NAEs水平显著降低。另一方面，在NAPE-PLD+/+和NAPE-PLD-大脑中发现了nape的互补谱，后者的饱和n -酰基nape水平高15-20倍，这些数据表明NAPE-PLD是哺乳动物将nape转化为NAEs的主要酶。

N-Acylethanolamines (NAEs) constitute a large and diverse class of signaling lipids that includes the endogenous cannabinoid anandamide. It is widely accepted that in mammalian tissues all NAEs are principally released from their corresponding N-acyl phosphatidylethanolamines (NAPEs) by the catalysis by a membrane-associated phospholipase D generally abbreviated as NAPE-PLD. Recently, NAPE-PLD was identified as a candidate enzyme involved in the biosynthesis of NAEs by us. To understand the physiological and pathophysiological significance of anandamide and other bioactive NAEs in mammals, we generated and characterized mice with a targeted disruption in the NAPE-PLD gene (NAPE-PLD-1). (1) lb generate mice lacking NAPE-PLD, exon 3 of the NAPE-PLD gene was removed by Cre/loxP system. (2) NAPE-PLD-1- were born at the expected Mendelian frequency, were viable and healthy, and showed no overt differences in their cage behavior compared to wild type littermates. (3) RT-PCR and Western blotting with anti-NAPE-PLD antibodies confirmed the absence of NAPE-PLD mRNA and protein in tissues from NAPE-PLO-h. (4) Tissues from NAPE FED" showed significantly lower NAPE-PLD activity with an N-palmitoyl-PE as substrate compared to wild type tissues. (5) Significant reductions in the levels of saturated NAEs were observed in NAPE-PLO-I brains. On the other hand, complementary profiles of NAPEs were found in NAPE-PLD+/+ and NAPE-PLD-1- brains, with the latter samples possessing 15-20-fold higher levels of saturated N-acyl NAPEs, These data suggest that NAPE-PLD is a principal enzyme responsible for the conversion of NAPEs to NAEs in mammals.