Study On The Pleural Lymphatic Stomata And Nitric Oxide Regulation On Lymph Drainage And NO-cGMP-Ca～(2+) Pathway

Background Peritoneal lymphatic stomata are openings of the peritoneal lymphatic vessels into the peritoneal cavity. The peritoneal cavity is connected with the vascular system by the lymphatic stomata. It is the most important pathway to drainage of substance in the peritoneal cavity, and plays an extremely important role in physiological and pathological conditions.In 1863, von Recklinghausen firstly described that there are some pores existing among the adjoining peritoneal mesothelium, and named them as the peritoneal lymphatic stomata. He considered that the peritoneal cavity was connected with the lymph system by the stomata. But at that time his standpoint was controversial. In 1977, Tsilibary and Wissig confirmed the lymphatic stomata in mouse diaphragm by electron microscopy. Later a number of researchers made detailed studies about the peritoneal lymphatic stomata in different animals and human being including the structure and function, the distribution, the development, and the regulations etc.It is showed that the lymphatic stomata are surrounded by cuboidal mesothelial cells. They are relatively stable structure, and drained of fluid, particulate material and especially cells from the serious cavity. The lymphatic stomata distribute not only in the diaphragm but also in the pelvic peritoneum, in the omentum, in the pericardium and in the ovarian bursaand etc.Li Jicheng and Yu Shouming reported human peritoneal lymphatic stomata in fetuses aging from 20-32 weeks. Nakatani et al. studied the detailed process of lymphatic stomata formation. Li Hui and Li Jicheng found that lymphatic stomata firstly appeared on embryonic day 15 in the mice, but only those postnatal lymphatic stomata have absorptive function.The regulation of the lymphatic stomata is the most noticeable topic in the field. It has been known that the peritoneal are adjustable by some factors, i.e. intraabdominal pressure, some traditional Chinese medicine, nitric oxide (NO) and vascular endothelial growth factor (VEGF), etc. Tsilibary and Wissig found that stomata open when fluid pressure within the peritoneal cavity is elevated. The stomata also open when the diaphragm is stimulated to relax with succinylcholine and closed when treated with carbachol. Sui Meihua and Li Jicheng reported recently that both the openings and absorptive functions of the lymphatic stomata of ovary bursa in guinea pig could be enhanced by pregnancy and decreased by exogenous homone. Li Jicheng et al. suggested that Chinese meteria medica could regulate the patency of the lymphatic stomata. He also found that the increased NO production in long-term peritoneal dialysis could relax lymphatic stomata leading to the enhanced lymph absorption or ultrafiltration failure. Ding Shiping and Li Jicheng lately proved that NO is the key factor of Chinese meteria medica regulate lymphatic stomta and removing ascites. But, there are no reports on the cell signal transduction mechanism of NO regulating lymphatic stomata and lymph drainage.However, the material about the structure of pleural lymphatic stomata is limited, and even no reports on regulation of the pleural lymphatic stomata. In the present experiment, we studied detailed ultrastructure of pleural lymphatic stomata and the effect of NO on the pleural lymphatic stomata and lymph absorption from the pleural cavity. These study has great significant in the explaination of hydrothorax formation, expression of infection and tumor metastasis in the pleural cavity. We also studied the cell signal transduction mechanism of NO on lymphatic stomata and lymph absorption expecting to provide some evidence for the Chinese meteria medica regulating lymphatic stomata and promoting curative effect of peritoneal dialysis.Objective (1) To study the ultrastructural structure of costal lymphatic stomata in the rabbit. (2) To study the effect of NO on the drainage capacity of pleural lymphatic stomata in the rat. (3) To study the cell signal mechanism of NO on the lymphatic stomata and lymph drainage capacity in th...