It has been shown that NO signaling during both PCD and defence responses requires cyclic GMP and cyclic ADP ribose, two molecules that can serve as secondary messengers for NO signaling in mammals.

• 现已证明，NO信号在PCD和防御反应时要求循环GMP和循环ADP核糖，这两个分子可作为NO信号在哺乳动物中的二级信使。