Analysis of the relationship between muscle sympathetic nerve activity and cardiac123I-metaiodobenzylguanidine uptake in patients with Parkinson's disease

2005 ◽  
Vol 20 (11) ◽  
pp. 1419-1424 ◽  
Author(s):  
Kazumasa Shindo ◽  
Eri Kaneko ◽  
Harue Watanabe ◽  
Tetsuhiko Sugimoto ◽  
Emiko Ohta ◽  
...  
2001 ◽  
Vol 91 (4) ◽  
pp. 1679-1686 ◽  
Author(s):  
Jian Cui ◽  
Thad E. Wilson ◽  
Manabu Shibasaki ◽  
Nicole A. Hodges ◽  
Craig G. Crandall

To identify whether muscle metaboreceptor stimulation alters baroreflex control of muscle sympathetic nerve activity (MSNA), MSNA, beat-by-beat arterial blood pressure (Finapres), and electrocardiogram were recorded in 11 healthy subjects in the supine position. Subjects performed 2 min of isometric handgrip exercise at 40% of maximal voluntary contraction followed by 2.5 min of posthandgrip muscle ischemia. During muscle ischemia, blood pressure was lowered and then raised by intravenous bolus infusions of sodium nitroprusside and phenylephrine HCl, respectively. The slope of the relationship between MSNA and diastolic blood pressure was more negative ( P < 0.001) during posthandgrip muscle ischemia (−201.9 ± 20.4 units · beat−1 · mmHg−1) when compared with control conditions (−142.7 ± 17.3 units · beat−1 · mmHg−1). No significant change in the slope of the relationship between heart rate and systolic blood pressure was observed. However, both curves shifted during postexercise ischemia to accommodate the elevation in blood pressure and MSNA that occurs with this condition. These data suggest that the sensitivity of baroreflex modulation of MSNA is elevated by muscle metaboreceptor stimulation, whereas the sensitivity of baroreflex of modulate heart rate is unchanged during posthandgrip muscle ischemia.


2019 ◽  
Vol 317 (6) ◽  
pp. H1203-H1209 ◽  
Author(s):  
Sarah L. Hissen ◽  
Vaughan G. Macefield ◽  
Rachael Brown ◽  
Chloe E. Taylor

Sympathetic baroreflex sensitivity (BRS) is a measure of how effectively the baroreflex buffers beat-to-beat changes in blood pressure through the modulation of muscle sympathetic nerve activity (MSNA). However, current methods of assessment do not take into account the transduction of sympathetic nerve activity at the level of the vasculature, which is known to vary between individuals. In this study we tested the hypothesis that there is an inverse relationship between sympathetic BRS and vascular transduction. In 38 (18 men) healthy adults, continuous measurements of blood pressure, MSNA and superficial femoral artery diameter and blood flow (Doppler ultrasound) were recorded during 10 min of rest. Spontaneous sympathetic BRS was quantified as the relationship between diastolic pressure and MSNA burst incidence. Vascular transduction was quantified by plotting the changes in leg vascular conductance for 10 cardiac cycles following each burst of MSNA, and taking the nadir. In men, sympathetic BRS was inversely related to vascular transduction ( r = −0.49; P = 0.04). However, this relationship was not present in women ( r = −0.17; P = 0.47). To conclude, an interaction exists between sympathetic BRS and vascular transduction in healthy men, such that men with high sympathetic BRS have low vascular transduction and vice versa. This may be to ensure that blood pressure is regulated effectively, although further research is needed to explore what mechanisms are involved and examine why this relationship was not apparent in women. NEW & NOTEWORTHY Evidence suggests that compensatory interactions exist between factors involved in cardiovascular control. This study was the first to demonstrate an inverse relationship between sympathetic BRS and beat-to-beat vascular transduction. Those with low sympathetic BRS had high vascular transduction and vice versa. However, this interaction was present in young men but not women.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
hiroyuki sugimoto ◽  
Hisayoshi Murai ◽  
Takuto Hamaoka ◽  
Yusuke Mukai ◽  
Yoshitaka Okabe ◽  
...  

Introduction: Augmented sympathetic nerve activity (SNA) in hypertension (HT) is regarded as a therapeutic target, but there is few non-invasive markers to evaluate SNA in clinical practice. It is reported to associate with SNA which increased arterial reflected wave plays the important role in disease progression in HT, and it is reported to associate with SNA. Recently, Arterial Velocity Pulse Index (AVI) are developed as an index of arterial reflected waves, however the relationship between AVI and SNA is still uncertain. Methods: Patients with essential HT and matched non-hypertensive control subjects were included in this study. HT was diagnosed as systolic blood pressure (SBP) ≧ 140 mmHg or diastolic blood pressure (DBP) ≧ 90 mmHg. Patients with secondary HT was excluded. AVI was measured from left upper arm by NAS-1000 (Nihon Koden, Japan). SNA was evaluated by direct recording of muscle sympathetic nerve activity (MSNA) from peroneal nerves. Results: 50 HT patients and 50 control subjects were included. Age, SBP and DBP were significantly increased in HT group compared to control (Age 63±14 vs 42±16 years, p<0.001; SBP 144±16 vs 115±9 mmHg, p<0.001; DBP 80±14 vs 67±9 mmHg, p<0.001). MSNA and AVI were significantly increased in HT group compared to control (MSNA 34±10 vs 25±8 bursts/min, p<0.05; AVI 28±9 vs 17±5, p<0.05). In univariate analysis, AVI was significantly correlated with MSNA, age, and SBP in HT group. However, no significant relationship was observed between AVI and MSNA in multivariate analysis. Therefore, HT group was divided into two groups according to their severity (group 1, SBP<160mmHg, N=30; group 2, SBP>160 mmHg, N=20). AVI in group 1 showed significantly correlation with MSNA (r=0.49, p<0.05), but no correlation was seen in group 2. Conclusions: AVI was significantly increased in patients with HT compared to control, and AVI is significantly associated with MSNA in HT patients with SBP<160mmHg. These results indicate that AVI is helpful to estimate augmented SNA in patients with mild or moderate hypertension. Further study is warranted to exam the relationship AVI and SNA in reality.


2002 ◽  
Vol 282 (5) ◽  
pp. H1717-H1723 ◽  
Author(s):  
Jian Cui ◽  
Thad E. Wilson ◽  
Craig G. Crandall

The purpose of this project was to test the hypothesis that baroreceptor modulation of muscle sympathetic nerve activity (MSNA) and heart rate is altered during the cold pressor test. Ten subjects were exposed to a cold pressor test by immersing a hand in ice water for 3 min while arterial blood pressure, heart rate, and MSNA were recorded. During the second and third minute of the cold pressor test, blood pressure was lowered and then raised by intravenous bolus infusions of sodium nitroprusside and phenylephrine HCl, respectively. The slope of the relationship between MSNA and diastolic blood pressure was more negative ( P < 0.005) during the cold pressor test (−244.9 ± 26.3 units · beat−1 · mmHg−1) when compared with control conditions (−138.8 ± 18.6 units · beat−1 · mmHg−1), whereas no significant change in the slope of the relationship between heart rate and systolic blood pressure was observed. These data suggest that baroreceptors remain capable of modulating MSNA and heart rate during a cold pressor test; however, the sensitivity of baroreflex modulation of MSNA is elevated without altering the sensitivity of baroreflex control of heart rate.


Sign in / Sign up

Export Citation Format

Share Document