Effects of acute ammonia exposure and post-exposure recovery on nonspecific immunity in Clam Cyclina sinensis

Abstract

This study aimed to assess the toxicity of ammonia on clam Cyclina sinensis and the post-exposure recovery. With increased exposure to TAN, the alkaline phosphatase (AKP) activities after exposure showed a trend of growing initially and subsequently decreasing, whereas the AKP activities after post-exposure recovery showed an increasing trend. The AKP activities after post-exposure recovery were significantly higher than those in control. The acid phosphatase (ACP) activities in T1 and T2 after post-exposure recovery were higher than those in the control, whereas the ACP activities in T3, T4, and T5 after postexposure recovery were significantly higher than those in the control. The lysozyme (LZM) activities in T1 and T2 after exposure were significantly higher than those in control, whereas the LZM activities in T3, T4, and T5 after exposure were significantly lower than those in the control. Overall, ACP and LZM in the clams exposed to a low level of TAN (≤ 40 mg/L) can recover to the normal levels completely. However, a 48h recovery period scarcely seems adequate to compensate for AKP, ACP, and LZM activities in the clams exposed to a high level of TAN (> 40 mg/L).

Effect of chronic ammonia nitrogen stress on the SOD activity and interferon-induced transmembrane protein 1 expression in the clam Cyclina sinensis

“…The SOD activity in clams infected with V. parahaemolyticus for 144 h did not return to the control group's normal level. The reason may be that the bacterial infection may have caused irreparable damage to the antioxidant system, or it could be due to the 144-h recovery time being too short for the recovery of the SOD activity (Ge et al, 2022a).…”

“…The hepatopancreas was collected and then frozen in liquid nitrogen for the SOD activity analysis and total RNA isolation. The SOD activity was determined using kits purchased from Nanjing Jiancheng Bioengineering Institute (Ge et al, 2022a).…”

“…As an unavoidable factor, ammonia nitrogen easily accumulates in the aquaculture system (Barbieri and Bondioli, 2013;Egnew et al, 2019). The accumulation of total ammonia nitrogen (TAN) in the water environment can ultimately lead to severe problems such as oxidative stress (Ge et al, 2022a), gill hyperplasia (Zuffo et al, 2021), inefficient feed utilization (Silva et al, 2018), and poor immune response of aquatic animals (Mangang and Pandey, 2021). As a result, some opportunistic bacteria such as Vibrio parahaemolyticus may cause serious vibriosis (Ni et al, 2020).…”

“…In some cases, it could even lead to death in aquatic animals (Barbieri et al, 2019). Aquatic animals suffer from oxidative stress, which causes the accumulation of reactive oxygen species (ROS) (Ge et al, 2022a), and the scavenging capacity induces lipid peroxidation (Debbarma et al, 2021). To protect organisms from such oxidative stress, antioxidant enzymes are likely to be activated.…”

“…The clam is highly adaptable to ammonia nitrogen (Ni et al, 2022). However, when the accumulation of ammonia nitrogen reaches the threshold level, this can have serious effects on the clam, including oxidative stress and poor immune response (Ni et al, 2021;Ge et al, 2022a). Therefore, it is essential to evaluate the effects of ammonia nitrogen on antioxidant enzymes and immunoreaction (Chai et al, 2022).…”