Biology Reference
In-Depth Information
DNA synthesis was determined in the cells by measuring the incorpora-
tion of
3
H-thymidine for 2-3 h in the growth medium (0.5
m
Ci/ml).
Laser irradiation
was applied on the cells directly using a 632.8-nm, 5-mW
He-Ne laser, and diameter of laser beam 2.7 mm
2.7 mm. Level measure-
ments of DNA and CK in young and mature skeletal muscle cells were per-
formed at seven time points: control (for young and mature cells,
respectively) and 1, 3, 7, 10, 14, and 21 min of laser irradiation. Total
CK activity was measured in the cell homogenate.
Statistical analysis
and calculations were done using MatLab software
(Ver. 2008b, The MathWorks, Inc.). We used nonparametric statistics since
the number of rats in each sample time point was too small to evaluate nor-
mal deviation. The figure presentation is aligned with our statistics, thus
all figures are presented with Median
Mad. All significance levels were
calculated using a Mann-Whitney
U
test when samples are independent
observations (e.g., when comparing the results between rats that were
treated with laser and ones that had no treatment) andWilcoxon signed-rank
test when comparing two related samples (e.g., when comparing the results
between laser-irradiated and nonirradiated leg of the same rat). Correlations
between muscles in the same rat (laser-irradiated and nonirradiated) were
calculated to evaluate the dynamic change of AChR and CK in time.
In vivo muscle response
.
Figures 4.1 and 4.2
present qualitative changes
in amount of AChR and CK activity in irradiated (first 14 days) and non-
irradiated intact gastrocnemius muscles. Laser irradiation significantly
increased CK activity (
p
<
0.05) and AChR level (
p
<
0.01) in time
periods of 30-60 days in comparison with the nonirradiated gastrocnemius
muscles.
In vitro muscle cells response
.
Figure 4.3
shows the effect of 632-nm laser
irradiation on the synthesis of DNA in young and mature skeletal muscle
cells at seven time points (control, 1, 3, 7, 10, 14, 21 min of irradiation).
Similar increase in DNA synthesis in both groups was found with tendency
to decrease during the radiated time.
Figure 4.4
shows the effect of 632-nm
laser irradiation on the CK activity in young and mature skeletal muscle cells
at seven time points (control [4;4 for young and mature cells, respectively];
min 1 [
n
¼
0;4]; min 3 [
n
¼
4;4]; min 7 [
n
¼
3;4]; min 10 [
n
¼
0;4]; min
14 [
n
3;3]). In the laser-irradiated mature muscle fibers,
the activity of CK was more expressed than in young cells and control level.
Figure 4.5
shows in comparison the effect of 632-nm laser irradiation on
CK activity and DNA synthesis in young and mature skeletal muscle cells.
To evaluate the laser treatment effect, we calculated all cell results between 1
¼
3;2]; min 21 [
n
¼
