Our results showed that the normal physiological processes of haemocytes were restrained under this acute stress, such as generation of
ROS and NO, and esterase activity. The decrease of ROS might result
from decreased activity of NADPH oxidase responsible for production
of O2, or from destroyed oxidative activity of mitochondria. Similarly,
the decline on NO production might due to repressed NO-synthase activity. Nitrite might damage related functional proteins as it destroyed
oxyhemocyanin (Chen and Cheng, 1995a, 1995b), yet there is still no direct evidence that nitrite would destroy NADPH oxidase, NO-synthase
and mitochondria oxidative activity. More studies should be done to
confirm this hypothesis.