The effect of 7.2% hypertonic saline solution on the duration of sodium gradient between the cerebrospinal fluid and the venous circulation in the dog.

To determine the duration of water movement from cerebrospinal fluid (CSF) into venous blood by the infusion of 7.2% hypertonic saline solution (HSS), the sodium gradient between venous blood and CSF were examined. Venous sodium concentrations remained higher than that in CSF for duration of 60 min following HSS infusion. By 90 min, the CSF sodium concentration reached the equilibrium with venous sodium concentration. Those data suggests that the duration of time during which water moved from CSF into capillaries in brain by the gradient of sodium concentration was less than 90 min.

Prostaglandin E2 activates Src signaling in lung adenocarcinoma cell via EP3.

Accumulating evidence suggests that overproduction of prostaglandin (PG) E2 attributable to induction of cyclooxygenase-2 plays an important role in the development of lung adenocarcinoma. Recently, we have reported that a PGE2 receptor, EP3 is involved in appearance of malignant phenotype of a lung adenocarcinoma cell (A549 cell). In line with our previous study, here we investigated if Src signaling could be involved in PGE2-stimulated growth of A549 cells via EP3. PGE2-dependent cell growth in A549 cell positively related to the activation of Src. A specific antagonist against EP3 abrogated the cell growth and Src activation in the cells stimulated with PGE2. Also, the inhibition of Src activity suppressed its downstream signaling related to cell growth as well as the cell growth in the cells treated with PGE2. These results indicate that PGE2-dependent activation of Src signaling via EP3 plays an important role in growth of A549 cells.