Altered interaction between plasminogen activator inhibitor type 1 activity and sympathetic nerve activity with aging.
BACKGROUND
It has been reported that sympathetic nerve activity (SNA) is associated with fibrinolysis, but the interaction between SNA and the fibrinolytic system with aging has not been elucidated in humans. The purpose of this study was to examine the effect of age-related SNA on the activity of plasminogen activator inhibitor type 1 (PAI-1) and tissue plasminogen activator (tPA) using muscle SNA (MSNA).


RESULTS
This study included 16 young subjects (mean age 26.1 years) and 10 aged subjects (mean age 56.9 years). Lower body negative pressure (LBNP) was performed at -40 mmHg for 30 min. LBNP significantly increased both tPA and PAI-1 activity (from 5.2+/-0.5 to 7.3+/-1.2 IU/ml and from 2.85+/-0.68 to 4.06+/-0.73 U/ml, p<0.01, respectively) in the aged group. In the young group, tPA activity tended to increase, whereas PAI-1 activity was unchanged. There was a correlation between MSNA and PAI-1 activity in the aged group (r=0.47, p<0.01).


CONCLUSIONS
SNA in an aging subject leads to an increase in the activity of PAI-1, which indicates that an altered interaction between SNA and PAI-1 activity contributes to increased cardiovascular events in the elderly population.
Otowa
Kan-Ichi
K
Department of Disease Control and Homeostasis, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan. otowanomori@gmail.com
Takamura
Masayuki
M
Murai
Hisayoshi
H
Maruyama
Michirou
M
Nakano
Manabu
M
Ikeda
Tatsunori
T
Kobayashi
Daisuke
D
Ootsuji
Hiroshi
H
Okajima
Masaki
M
Furushou
Hiroshi
H
Yuasa
Toyoshi
T
Takata
Shigeo
S
Kaneko
Shuichi
S
D000328:Adult; D000368:Aged; D000375:Aging / Q000097:blood* / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D005260:Female; D005342:Fibrinolysis / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008150:Lower Body Negative Pressure; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood / Q000502:physiology*; D013564:Sympathetic Nervous System / Q000502:physiology*; D010959:Tissue Plasminogen Activator / Q000097:blood / Q000502:physiology
D017395:Plasminogen Activator Inhibitor 1; D010959:Tissue Plasminogen Activator