The Effect Of Simulated Air Conventional Diving On The Function Of Murine Peritoneal Macrophages

With the developments of ocean exploitation and hyperbaric oxygen therapy, the chances of human being exposed to hyperbaric environment increased step by step and the effect of abnormal environment on human immune functions has been attracting more and more researchers' attention. There was evidence which proved that hyperbaric environment could affect man or animal immune functions. However, these data were mostly on hyperbaric oxygen, hyperoxia and saturation diving. Data showed that types of hyperbaric exposure could inhibit immune function of human to a certain degree according to various exposure pressure and time. Because of its ripe techniques and low expenditure, air conventional diving, compressed air used as its breathing gas, was the most adoptive way of diving in underwater working and recreation around the world. But there have been few of the articles about the air conventional diving on human immune functions and the results were varied. There was need for us to study the effects of air conventional diving on immune functions systemically and thoroughly.Macrophage was one important member of monocyte-macrophages system. It not only took part in body's nonspecific immunity and specific immunity but also its antigen process and presentation function was the base of specific immunity of human. It linked the two type reactions as a "bridge cell". Macrophages played an important role in immunity of human.In this study, we observed the functions of murine peritoneal macrophagaes after treatment of several frequently used programs of air diving, and analyzed the possible contributing factors. The possible mechanisms of immune changes were explored in vivo and vitro. The following results were acquired: 1. Compared with those in NA group, the activity of phagocytosis and acid phosphatase, antigen presentation function and the produce of NO and TNF-αwere markedly inhibited in HO group and HA1 group and they changed little in HN group. These changes could disappear in 3-5 days. 2. Compared with those in NA group, the activity of glutathione-s-transferase, glutathione peroxidase, superoxide dismutase and catalase and the level of glutathione were markedly inhibited and maleic dialdehyde increased in HO group and HA1 group. These changes could also disappear in 3-5 days.3. Compared with those in NA group, the activity of phagocytosis, the function of Fc receptor, the produce of NO and TNF-α, the expression of I region associated antigen and the antigen presentation functions were markedly inhibited after single hyperbaric oxygen exposure (400 kPa, 4 h or 6 h). And they changed little in HO1 group (200 kPa, 4 h).These results suggested that: ⑴ Simulated air diving with a certain pressure-time and frequency could inhibit the functions of mice peritoneal macrophages obviously; ⑵ Hyperbaric oxygen may play an important role in it; ⑶ The changes of peritoneal macrophages' functions after simulated air diving may related to its own oxidative stress states; ⑷ The inhibition of antigen presentation functions of peritoneal macrophages might be related to the decrease of expression of I region associated antigen.Taken together, air diving with a certain pressure-time frequency could inhibit the functions of mice peritoneal macrophages obviously and hyperbaric oxygen might be the key factor in the process. Hyperbaric oxygen might exert its effects on antigen presentation functions of macrophages through modifying the expression of I region associated antigen. Our research provided some laboratory evidences for the research of the effect of hyperbaric environment on human immune functions.