title: [Effects of nitric oxide on peritoneal lymphatic stomata and lymph drainage via NO-cGMP-Ca2+ pathway].
abstract: To study the cell signal transduction mechanism of nitric oxide (NO) on the peritoneal lymphatic stomata and lymph drainage in the rat, cGMP content were measured by a commercially available radioimmunoassay kit, and the [Ca(2+)](i) were observed by a confocal laser scanning microscope in the cultured peritoneal mesothelial cell. Animal experiment was practiced to study the effect of NO-cGMP-Ca(2+) pathway on the lymphatic stomata and lymph absorption. The results showed that: (1) Sper/NO increased cGMP of the rat peritoneal mesothelial cell (RPMC) in a dose-dependent manner (P<0.01) compared to the control group. This effect was blocked by 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ) (P<0.05), a specific inhibitor of soluble guanylyl cyclase (sGC). The level of [Ca(2+)](i) in single RPMC decreased by adding Sper/NO (P<0.05). Pretreatment with ODQ for 10 min blocked the Sper/NO-induced decrease in [Ca(2+)](i). L-typed calcium channel blocker nifedipine induced an immediate and marked decrease in [Ca(2+)](i) (P<0.05).. After [Ca(2+)](i) reached a balance again, adding Sper/NO could not change [Ca(2+)](i) (P>0.05). (2) Sper/NO increased the area of the stomata (P<0.01) and the quantity of the tracer in a dose-dependent manner (P<0.05) compared to the control group. Pretreatment with ODQ significantly inhibited Sper/NO-induced change of lymphatic stomata and lymph drainage (P<0.01). Nifedipine increased the opening area of the lymphatic stomata (P< 0.01) and the concentration of absorbed trypan blue of the diaphragm (P<0.05). Sper/NO could not make a further change in the samples pretreated by nifedipine (P> 0.05). The results indicate that NO can decrease [Ca(2+)](i) in the RPMC through the NO-cGMP pathway. This procession is related with the L- type voltage-gated Ca(2+) channel. NO enlarges the opening area of the lymphatic stomata and enhances the lymph drainage of tracer by NO-cGMP-[Ca(2+)](i) pathway.
authors.affiliation: Department of Lymphology, Institute of Cell Biology, Zhejiang University, Hangzhou 310031, China.
authors.forename: Yan-Yuan
authors.initials: YY
authors.lastname: Li
authors.forename: Ji-Cheng
authors.initials: JC
authors.lastname: Li
mesh_terms: D000818:Animals; D020013:Calcium Signaling / Q000502:physiology*; D006152:Cyclic GMP / Q000378:metabolism*; D005260:Female; D008196:Lymph / Q000502:physiology*; D042601:Lymphatic Vessels / Q000502:physiology; D008297:Male; D009569:Nitric Oxide / Q000502:physiology*; D054048:Peritoneal Stomata / Q000502:physiology*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D009569:Nitric Oxide; D006152:Cyclic GMP