Gravity and cyclic GMP levels in melanocytic cells.
Guanosine 3',5'-cyclic monophosphate (cyclic GMP) is a major second messenger molecule, that is believed to play a role in various physiological and pathophysiological processes. Here we report that hypergravity induces differential effects on cyclic GMP turnover in melanocytic cells. Nonmetastatic melanoma cells responded to long-time exposure (24 h) of hypergravity (up to 5 x g) with decrease in intracellular cyclic GMP accumulation in the presence of an universal inhibitor of phosphodiesterases (IBMX), whereas the extracellular cyclic GMP increase. In contrast, there were no changes in cyclic GMP turnover in metastatic melanocytes. The expression of the guanylyl cyclases appeared to be not affected. These results suggest that cyclic GMP signaling may be involved in adaptation of human melanocytes to altered gravity conditions.
Institute of Aerospace Medicine, DLR, Linder Hohe, Cologne, Germany. krassimira.ivanova@dlr.de
Krassimira
K
Ivanova
Nahid Hamidi
NH
Zadeh
Ingrid
I
Block
Pranab K
PK
Das
Rupert
R
Gerzer