Low-power laser irradiation increases cyclic GMP synthesis in penile smooth muscle cells in vitro.
OBJECTIVE
The objective of the present study was to determine the effect of low-power laser irradiation (LPLI) on cyclic guanosine monophosphate (cGMP) produced by human corpus cavernosum smooth muscle cells (HCC SMC) in vitro.


BACKGROUND
Numerous reports suggest that LPLI is capable of affecting cellular processes in the absence of significant thermal effect


METHODS
HCC SMC cultures were irradiated with single-dose LPLI using a He-Ne continuous wave laser (632 nm) with different energy densities (0.52-2.1 J/cm2). Assessment of effect on cell viability was performed utilizing Alamar Blue assay. Effect of LPLI on cGMP production was studied by radioimmunoassay.


RESULTS
We observed that: (1) LPLI of HCC SMC results in a statistically significant increase of cGMP synthesis in culture and is dose dependent (maximal effect was observed with LPLI irradiance of 1.57 J/cm2. (2) There were no changes in Normalized Viability Index (NVI) immediately after and 24 h following laser irradiation.


CONCLUSIONS
Our studies demonstrate that LPLI irradiation stimulates elevation of cGMP in vitro.
Kipshidze
N
N
Lenox Hill Heart and Vascular Institute of New York, Cardiovascular Research Foundation, New York, New York 10021, USA. nkipshidze@lenoxhill.net
Petersen
J R
JR
Vossoughi
J
J
Nikolaychik
V
V
Bakhutashvili
I
I
Roubin
G S
GS
Leon
M B
MB
Moses
J W
JW
D000328:Adult; D002478:Cells, Cultured; D006152:Cyclic GMP / Q000096:biosynthesis*; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D007834:Lasers; D008297:Male; D009130:Muscle, Smooth / Q000166:cytology* / Q000528:radiation effects*; D010413:Penis / Q000166:cytology
D006152:Cyclic GMP