Borgers M, Thoné F
Janssen Research Foundation, Beerse, Belgium.
Histochem J. 1992 Jul;24(7):445-52. doi: 10.1007/BF01089106.
5'-Nucleotidase and purine nucleoside phosphorylase, two key enzymes in nucleoside metabolism, have been localized electronmicroscopically in left ventricular myocardium of the human, dog, pig, rabbit, guinea pig and rat. Ectonucleotidase activity was present in all species at the plasma membrane of pericytes. Reactive endothelial cells in the microcirculatory bed were restricted to those covering resistance arterioles. Cardiomyocytes were reactive only in the rat. Purine nucleoside phosphorylase was localized uniformly in the vascular endothelium of all species. The strongest activity was seen in the pericytes of guinea pig, rat and dog. Pericytes of rabbit and pig were virtually unreactive, whereas a minority of cells in human samples were positive. Cardiomyocytes were unreactive in all species. These variations in the distribution pattern of adenosine metabolic sites may have definite consequences for disposal and recovery of adenylates and their breakdown products in ischaemia and for the effects to be expected from interference with nucleoside transport inhibition.
5'-核苷酸酶和嘌呤核苷磷酸化酶是核苷代谢中的两种关键酶，已通过电子显微镜定位在人类、狗、猪、兔、豚鼠和大鼠的左心室心肌中。所有物种的周细胞质膜均存在外核苷酸酶活性。微循环床中的反应性内皮细胞仅限于覆盖阻力小动脉的细胞。心肌细胞仅在大鼠中具有反应性。嘌呤核苷磷酸化酶在所有物种的血管内皮中均呈均匀分布。在豚鼠、大鼠和狗的周细胞中观察到最强的活性。兔和猪的周细胞几乎无反应，而人类样本中的少数细胞呈阳性。所有物种的心肌细胞均无反应。腺苷代谢位点分布模式的这些变化可能对缺血时腺苷酸及其分解产物的处置和回收以及对核苷转运抑制干扰预期产生的影响具有明确的后果。
