of如何理解？

Modulation by the Endothelial Cell of the Pulmonary Artery Smooth Muscle Cells

内皮细胞对肺动脉平滑肌细胞的调节作用

Endothelial cell activity may either enhance or inhibit HPV . Inhibitors of HPV include prostacyclin (PGI2) and NO, both of which may exist to maintain some perfusion of hypoxic lung regions, although their role in normal lung is uncertain. For example, PGI2 is a potent pulmonary vasodilator, but cyclooxygenase, which is required for its production, is inhibited by hypoxia, which may therefore diminish the vasodilator effects.

内皮细胞活性可增强或抑制HPV。HPV的抑制剂包括前列环素（prostacyclin，PGI₂）和NO，PGI₂和NO在正常肺组织中的作用尚不明确，但在缺氧肺组织区域可能起到维持部分灌注的作用。例如，PGI₂是一种强效的肺血管扩张剂，但缺氧会抑制其生成所需的环氧合酶，因而可能会减弱PGI₂的血管扩张作用。

Similarly, basal NO secretion by endothelial cells may act to moderate HPV , but hypoxia also inhibits endothelial NO production enhancing HPV . Molecules that enhance HPV include thromboxane A2 (see later) and endothelin. Endothelin is a 21 amino acid peptide released by endothelial cells in response to hypoxia.2It is a potent vasoconstrictor peptide which has a prolonged effect on pulmonary vascular tone, such that this mechanism is probably involved in the second slow phase of HPV (Fig. 6.8). Endothelin is believed to be involved in producing the pulmonary hypertension associated with altitude hypoxia (see Chapter 16), although attempts to enhance HPV with endothelin infusions have not been successful.1T wo groups of endothelin receptors are described, ETA and ETB, and the ratio of these two receptors varies between the central and peripheral vasculature of the lung. Apart from its vasoconstrictor effects, endothelin can also stimulate cellular proliferation of either vascular endothelial cells or pulmonary fibroblasts, and has an important role in the pulmonary vascular remodelling that accompanies long-term hypoxia.

同样，内皮细胞分泌的基础NO会减弱HPV，但缺氧会抑制内皮细胞生成NO，从而增强HPV。增强HPV的分子包括血栓素A₂（见后文）和内皮素。内皮素是内皮细胞在缺氧时释放的一种21个氨基酸的多肽²¹，是一种能维持肺血管张力的长效且强效的血管收缩肽，因此可能参与HPV的第二慢反应相（图6.8）。虽通过注射内皮素增强HPV的尝试尚未成功，但现认为内皮素参与产生高原缺氧相关的肺动脉高压 （见第16章）¹³。ET_A和ET_B是内皮素受体的两种形式，两者在肺的中央和外周血管间比例不同。除血管收缩外，内皮素还能刺激血管内皮细胞或肺成纤维细胞增殖，并对长期缺氧下的肺血管重构发挥重要作用。

Modulation by the Endothelial Cell of the Pulmonary Artery Smooth Muscle Cells

“肺动脉平滑肌细胞的内皮细胞的调控”，“肺动脉平滑肌细胞”与“内皮细胞”是什么关系？

这个适不适合？如果这样的话，就是“来自肺动脉平滑肌细胞的内皮细胞的调节作用”？缺乏这方面的知识？

软件为什么会这么翻译

从下面的内容看，软件是对的，但就是这个of怎么理解？

要么是这个？