Abstract
Objective: To determine whether spectral powers of blood pressure and pulse interval can specifically reflect sympathetic and parasympathetic effects in unanesthetized, free-moving spontaneously hypertensive rats (SHR). Design: Spectral powers were observed before and after various autonomic interventions in chronically instrumented rats. Materials and methods: Chemical sympathectomy was produced in 12-week-old SHR by repeated injections of 6-hydroxydopamine, while control rats were given vehicle alone. Chronic arterial and venous catheters were inserted in the femoral artery and vein. Blood pressure was recorded beat-to-beat for 90 min in free-moving rats; further recording sessions were obtained under additional a-receptor blockade with phenoxybenzamine at 1 mg/kg and/or additional cholinergic blockade with atropine at 0.8 mg/kg. Off-line computer analysis (fast Fourier transform) provided estimates of low- (0.025-0.1 Hz), mid- (0.1-0.6 Hz) and high-frequency (0.8-3.0 Hz) powers for blood pressure and pulse interval over consecutive periods of 100 s. Results: The most noticeable findings were that sympathectomy produced a striking increase in the low-frequency power of blood pressure and a tendency (borderline statistical significance) to reduce the mid-frequency power of blood pressure. Additional a-receptor blockade had no effect on any spectral power whereas additional cholinergic blockade caused a further increase in the low-frequency blood pressure power and a drastic reduction in all pulse interval powers. Conclusions: In the unanesthetized SHR, sympathetic activity opposes low-frequency and marginally promotes mid-frequency blood pressure fluctuations; the pulse interval spectral expression of vagal effects is spread throughout the range of frequencies explored and is not confined to the high-frequency band. These data indicate that in SHR no spectral power can specifically reflect the effects of either autonomic limb.
| Original language | English |
|---|---|
| Pages (from-to) | 1636-1642 |
| Number of pages | 7 |
| Journal | Journal of Hypertension |
| Volume | 13 |
| Issue number | 12 |
| Publication status | Published - 1995 |
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Keywords
- Blood pressure variability
- Heart rate variability
- Spectral analysis
- Spontaneously hypertensive rats
- Wistar-Kyoto rats
ASJC Scopus subject areas
- Physiology
- Cardiology and Cardiovascular Medicine
- Internal Medicine
- Endocrinology
Cite this
Sympathetic, parasympathetic and non-autonomic contributions to cardiovascular spectral powers in unanesthetized spontaneously hypertensive rats. / Daffonchio, Anna; Franzelli, Cristina; Di Rienzo, Marco; Castiglioni, Paolo; Mancia, Giuseppe; Ferrari, Alberto U.
In: Journal of Hypertension, Vol. 13, No. 12, 1995, p. 1636-1642.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Sympathetic, parasympathetic and non-autonomic contributions to cardiovascular spectral powers in unanesthetized spontaneously hypertensive rats
AU - Daffonchio, Anna
AU - Franzelli, Cristina
AU - Di Rienzo, Marco
AU - Castiglioni, Paolo
AU - Mancia, Giuseppe
AU - Ferrari, Alberto U.
PY - 1995
Y1 - 1995
N2 - Objective: To determine whether spectral powers of blood pressure and pulse interval can specifically reflect sympathetic and parasympathetic effects in unanesthetized, free-moving spontaneously hypertensive rats (SHR). Design: Spectral powers were observed before and after various autonomic interventions in chronically instrumented rats. Materials and methods: Chemical sympathectomy was produced in 12-week-old SHR by repeated injections of 6-hydroxydopamine, while control rats were given vehicle alone. Chronic arterial and venous catheters were inserted in the femoral artery and vein. Blood pressure was recorded beat-to-beat for 90 min in free-moving rats; further recording sessions were obtained under additional a-receptor blockade with phenoxybenzamine at 1 mg/kg and/or additional cholinergic blockade with atropine at 0.8 mg/kg. Off-line computer analysis (fast Fourier transform) provided estimates of low- (0.025-0.1 Hz), mid- (0.1-0.6 Hz) and high-frequency (0.8-3.0 Hz) powers for blood pressure and pulse interval over consecutive periods of 100 s. Results: The most noticeable findings were that sympathectomy produced a striking increase in the low-frequency power of blood pressure and a tendency (borderline statistical significance) to reduce the mid-frequency power of blood pressure. Additional a-receptor blockade had no effect on any spectral power whereas additional cholinergic blockade caused a further increase in the low-frequency blood pressure power and a drastic reduction in all pulse interval powers. Conclusions: In the unanesthetized SHR, sympathetic activity opposes low-frequency and marginally promotes mid-frequency blood pressure fluctuations; the pulse interval spectral expression of vagal effects is spread throughout the range of frequencies explored and is not confined to the high-frequency band. These data indicate that in SHR no spectral power can specifically reflect the effects of either autonomic limb.
AB - Objective: To determine whether spectral powers of blood pressure and pulse interval can specifically reflect sympathetic and parasympathetic effects in unanesthetized, free-moving spontaneously hypertensive rats (SHR). Design: Spectral powers were observed before and after various autonomic interventions in chronically instrumented rats. Materials and methods: Chemical sympathectomy was produced in 12-week-old SHR by repeated injections of 6-hydroxydopamine, while control rats were given vehicle alone. Chronic arterial and venous catheters were inserted in the femoral artery and vein. Blood pressure was recorded beat-to-beat for 90 min in free-moving rats; further recording sessions were obtained under additional a-receptor blockade with phenoxybenzamine at 1 mg/kg and/or additional cholinergic blockade with atropine at 0.8 mg/kg. Off-line computer analysis (fast Fourier transform) provided estimates of low- (0.025-0.1 Hz), mid- (0.1-0.6 Hz) and high-frequency (0.8-3.0 Hz) powers for blood pressure and pulse interval over consecutive periods of 100 s. Results: The most noticeable findings were that sympathectomy produced a striking increase in the low-frequency power of blood pressure and a tendency (borderline statistical significance) to reduce the mid-frequency power of blood pressure. Additional a-receptor blockade had no effect on any spectral power whereas additional cholinergic blockade caused a further increase in the low-frequency blood pressure power and a drastic reduction in all pulse interval powers. Conclusions: In the unanesthetized SHR, sympathetic activity opposes low-frequency and marginally promotes mid-frequency blood pressure fluctuations; the pulse interval spectral expression of vagal effects is spread throughout the range of frequencies explored and is not confined to the high-frequency band. These data indicate that in SHR no spectral power can specifically reflect the effects of either autonomic limb.
KW - Blood pressure variability
KW - Heart rate variability
KW - Spectral analysis
KW - Spontaneously hypertensive rats
KW - Wistar-Kyoto rats
UR - http://www.scopus.com/inward/record.url?scp=0029609802&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029609802&partnerID=8YFLogxK
M3 - Article
C2 - 8903624
AN - SCOPUS:0029609802
VL - 13
SP - 1636
EP - 1642
JO - Journal of Hypertension
JF - Journal of Hypertension
SN - 0263-6352
IS - 12
ER -