TY - JOUR
T1 - Ultrasound at 27 kHz Increases Tissue Expression and Activity of Nitric Oxide Synthases in Acute Limb Ischemia in Rabbits
AU - Atar, Shaul
AU - Siegel, Robert J.
AU - Akel, Rami
AU - Ye, Yumei
AU - Lin, Yu
AU - Modi, Shreyas A.
AU - Sewani, Asif
AU - Tuero, Enrique
AU - Birnbaum, Yochai
N1 - Funding Information:
The study was funded by the Division of Cardiology, University of Texas Medical Branch, Galveston, Texas. The authors thank Barry F. Uretsky, MD, for his support.
PY - 2007/9
Y1 - 2007/9
N2 - Transcutaneous low-frequency ultrasound (US) preserves myocardial and skeletal muscle viability by increasing tissue perfusion through an undefined nitric oxide (NO)-dependent mechanism. We have examined whether US increases tissue expression and activity of the three nitric oxide synthase (NOS) isoforms: endothelial (eNOS), neuronal (nNOS) and inducible (iNOS). The two femoral arteries of four New Zealand rabbits were ligated for a total of 120 min. After 60 min of ligation, transcutaneous low-frequency US (27 kHz, 0.13 W/cm2) was applied for 60 min to one thigh, while the contra-lateral artery served as a control (total ischemia time = 120 min). Calcium-dependent (cNOS) and -independent (ciNOS) NOS activity, and concentration of total eNOS, ser-1177 phosphorylated eNOS (P-eNOS), nNOS and iNOS were then determined in the gracilis muscle. Compared with the control, US application significantly increased cNOS activity [3.34 ± 0.28 versus 3.87 ± 0.10 × 1000 counts per minute (cpm), respectively, p = 0.031] and ciNOS activity (1.99 ± 0.09 versus 3.26 ± 0.68 cpm, respectively, p < 0.001). Western immunoblotting revealed a significant increase in protein content of both iNOS (184.5 ± 1.08%; p < 0.0001) and P-eNOS (381.5 ± 2.47%; p <0.001), with only a small increase in total eNOS and nNOS expression. In conclusion, application of transcutaneous low-frequency US to ischemic muscular tissue significantly increases both cNOS and ciNOS activity by increasing eNOS phosphorylation and iNOS expression, respectively. (E-mail: [email protected]).
AB - Transcutaneous low-frequency ultrasound (US) preserves myocardial and skeletal muscle viability by increasing tissue perfusion through an undefined nitric oxide (NO)-dependent mechanism. We have examined whether US increases tissue expression and activity of the three nitric oxide synthase (NOS) isoforms: endothelial (eNOS), neuronal (nNOS) and inducible (iNOS). The two femoral arteries of four New Zealand rabbits were ligated for a total of 120 min. After 60 min of ligation, transcutaneous low-frequency US (27 kHz, 0.13 W/cm2) was applied for 60 min to one thigh, while the contra-lateral artery served as a control (total ischemia time = 120 min). Calcium-dependent (cNOS) and -independent (ciNOS) NOS activity, and concentration of total eNOS, ser-1177 phosphorylated eNOS (P-eNOS), nNOS and iNOS were then determined in the gracilis muscle. Compared with the control, US application significantly increased cNOS activity [3.34 ± 0.28 versus 3.87 ± 0.10 × 1000 counts per minute (cpm), respectively, p = 0.031] and ciNOS activity (1.99 ± 0.09 versus 3.26 ± 0.68 cpm, respectively, p < 0.001). Western immunoblotting revealed a significant increase in protein content of both iNOS (184.5 ± 1.08%; p < 0.0001) and P-eNOS (381.5 ± 2.47%; p <0.001), with only a small increase in total eNOS and nNOS expression. In conclusion, application of transcutaneous low-frequency US to ischemic muscular tissue significantly increases both cNOS and ciNOS activity by increasing eNOS phosphorylation and iNOS expression, respectively. (E-mail: [email protected]).
KW - Ischemia
KW - Nitric oxide synthase
KW - Phosphorylation
KW - Transcutaneous
KW - Ultrasound
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U2 - 10.1016/j.ultrasmedbio.2007.03.008
DO - 10.1016/j.ultrasmedbio.2007.03.008
M3 - Article
C2 - 17507145
AN - SCOPUS:34548120567
SN - 0301-5629
VL - 33
SP - 1483
EP - 1488
JO - Ultrasound in Medicine and Biology
JF - Ultrasound in Medicine and Biology
IS - 9
ER -