TY - JOUR
T1 - Effect of Losartan on the Acute Response of Human Elderly Skeletal Muscle to Exercise
AU - Heisterberg, Mette Flindt
AU - Andersen, Jesper L
AU - Schjerling, Peter
AU - Bülow, Jacob
AU - Lauersen, Jeppe Bo
AU - Roeber, Heidi L
AU - Kjaer, Michael
AU - Mackey, Abigail L
PY - 2018/2
Y1 - 2018/2
N2 - Purpose: To investigate the effect of blocking the angiotensin II Type I receptor (AT1R) upon the response to acute heavy-resistance exercise in elderly human skeletal muscle. The hypothesis was that AT1R blocking would result in a superior myogenic response accompanied by down-regulation of transforming growth factor-beta and up-regulation of insulin-like growth factor- 1 signaling. Methods: Twenty-eight healthy elderly men (+64 yr) were randomized into two groups, consuming either AT1R blocker (losartan, 100 mgIdj1) or placebo for 18 d before exercise. Participants performed one bout of heavy-unilateral-resistance exercise. Six muscle biopsies were obtained from the vastus lateralis muscles of each subject: two before exercise and four after exercise (4.5 h and 1, 4, and 7 d). Blood pressure and blood samples were collected at the same time points. Biopsies were sectioned for immunohistochemistry to determine the number of satellite cells associated with Type I and Type II fibers. Gene expression levels of Notch, connective tissue, and myogenic signaling pathways were determined by real-time reverse transcription polymerase chain reaction. Results: Changes over time were detected for circulating creatine kinase, the number of satellite cells per Type I fiber, and most of the gene targets, with no specific effect of losartan on these. However, when compared with placebo, losartan intake resulted in a greater suppression of myostatin messenger RNA. Conclusions: In general, there does not seem to be any effect of AT1R blocking on satellite cell number or myogenic pathways in elderly men in the days after one bout of heavy-resistance exercise.
AB - Purpose: To investigate the effect of blocking the angiotensin II Type I receptor (AT1R) upon the response to acute heavy-resistance exercise in elderly human skeletal muscle. The hypothesis was that AT1R blocking would result in a superior myogenic response accompanied by down-regulation of transforming growth factor-beta and up-regulation of insulin-like growth factor- 1 signaling. Methods: Twenty-eight healthy elderly men (+64 yr) were randomized into two groups, consuming either AT1R blocker (losartan, 100 mgIdj1) or placebo for 18 d before exercise. Participants performed one bout of heavy-unilateral-resistance exercise. Six muscle biopsies were obtained from the vastus lateralis muscles of each subject: two before exercise and four after exercise (4.5 h and 1, 4, and 7 d). Blood pressure and blood samples were collected at the same time points. Biopsies were sectioned for immunohistochemistry to determine the number of satellite cells associated with Type I and Type II fibers. Gene expression levels of Notch, connective tissue, and myogenic signaling pathways were determined by real-time reverse transcription polymerase chain reaction. Results: Changes over time were detected for circulating creatine kinase, the number of satellite cells per Type I fiber, and most of the gene targets, with no specific effect of losartan on these. However, when compared with placebo, losartan intake resulted in a greater suppression of myostatin messenger RNA. Conclusions: In general, there does not seem to be any effect of AT1R blocking on satellite cell number or myogenic pathways in elderly men in the days after one bout of heavy-resistance exercise.
KW - Journal Article
U2 - 10.1249/MSS.0000000000001438
DO - 10.1249/MSS.0000000000001438
M3 - Journal article
C2 - 29040223
SN - 0195-9131
VL - 50
SP - 225
EP - 235
JO - Medicine and Science in Sports and Exercise
JF - Medicine and Science in Sports and Exercise
IS - 2
ER -
