PDE3 itself inhibits the effects of a messenger molecule known as cAMP.

PDE3 本身会抑制一种名为 cAMP 的信使分子的作用。

It is a source of a messenger molecule called cAMP, and its activity is regulated by bicarbonate ions.

它是一种名为cAMP的信使分子的来源，其活动受到碳酸氢根离子的调节。

AHR is a transcription factor, meaning that it controls the process by which messenger molecules are copied from genes.

AHR的是一种转录因子，也就是说，它控制的信使分子的基因复制过程。