Respiratory waves of blood pressure in human subjects

1958 ◽  
Vol 45 (2) ◽  
pp. 154-157 ◽  
Author(s):  
G. I. Kositskii
Keyword(s):  
Blood Pressure ◽  
Human Subjects ◽  
Respiratory Waves

Plasma ascorbic acid concentrations relate inversely to blood pressure in human subjects

1993 ◽  
Vol 57 (2) ◽  
pp. 213-217 ◽  
Author(s):  
J P Moran ◽  
L Cohen ◽  
J M Greene ◽  
G Xu ◽  
E B Feldman ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Ascorbic Acid ◽  
Human Subjects ◽  
Plasma Ascorbic Acid

Abstract 047: Genetics and Environmental Influences on Ambulatory Blood Pressure in Rats Compared With Circadian Blood Pressure Variability in Human

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Mary S Lee ◽  
John S Lee ◽  
Jong Y Lee ◽  
Silvia H Azar ◽  
Franz Halberg
Keyword(s):  
Blood Pressure ◽  
Human Subjects ◽  
Disease Status ◽  
Least Square ◽  
Spontaneously Hypertensive ◽  
Adolescents And Adults ◽  
Nursing Mothers ◽  
Uterine Environment ◽  
Elder Adults ◽  
Circadian Blood Pressure Variability

Genetic susceptibility is an important factor in raising blood pressure (BP). Daily (circadian) rhythm characteristics are considered essential parameters for recognizing and treating increased risks in BP. To examine BP in genetics with environmental modifications, one-cell homozygous embryos were transferred into spontaneously hypertensive (SHR, pup:shr) or normotensive (WKY, pup:wky) rats' oviducts (embryos: s, w; oviduct-uterine: S, W) in a reciprocal fashion. Pups were cross-suckled at birth (nurses S, W) and weaned to normal diets at day-21. At Day-120, telemetered BPs were monitored for 5 consecutive days every 4 min and analyzed by the method of ANOVA. Ambulatory BP in 20 adolescents and adults were monitored automatically around the clock at 30-min to hourly intervals and analyzed by the least square rhythmometry method. As expected, shr BPs were markedly reduced when they were transplanted to the W-uterine and/or the W-lactation milieu (sSS vs. sSW, sWS and sWW: 197 vs.178, 147 and 178 mm Hg). BP in wky was significantly altered only in the wSW group (wWW vs, wSW: 127 vs.131 mm Hg). All subjects showed significant circadian fluctuations with a peak in the late afternoon hours in most human subjects and rats as a nocturnal animal mostly close to midnight hours, while shr with W-uterine (sWS) a bit delayed peak hour (00:45) and with combined W-uterine/W-nursing (sWW) a bit earlier peak hour (20:12). Circadian double amplitudes (2A) in the human subjects varied from 8 to 26 mm Hg with higher 2A in elder adults, and 3-8 mm Hg in rats with significantly higher fluctuations in shr groups as compared to that of wWW (7.5±0.7 for sSS, 8.3±0.6 for sSW vs. 4.7±0.3 mm Hg for wWW). The hypertensive-prone shr strain showed significantly lowered BPs in a normotensive WKY uterine environment and/or by WKY nursing mothers, indicating that environment influences can strongly modify genetic factors, yet the lowered shr MESORs by the WKY environments remained above the MESORs encountered in wky donors. Chronomes broader than circadian should be considered in interpreting BP responses as a gauge of vascular disease status.

Sleep-dependent changes in the coupling between heart period and blood pressure in human subjects

2008 ◽  
Vol 294 (5) ◽  
pp. R1686-R1692 ◽  
Author(s):  
Alessandro Silvani ◽  
Daniela Grimaldi ◽  
Stefano Vandi ◽  
Giorgio Barletta ◽  
Roberto Vetrugno ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Eye Movement ◽  
Sleep Disordered Breathing ◽  
Human Subjects ◽  
Rapid Eye Movement Sleep ◽  
Heart Period ◽  
Low Frequencies ◽  
Feed Forward ◽  
Finger Blood Pressure ◽  
Spontaneous Fluctuations

We investigated whether in human subjects, the pattern of coupling between the spontaneous fluctuations of heart period (HP) and those of systolic blood pressure (SBP) differs among wake-sleep states. Polysomnographic recordings and finger blood pressure measurements were performed for 48 h in 15 nonobese adults without sleep-disordered breathing. The cross-correlation function (CCF) between the fluctuations of HP and SBP at frequencies <0.15 Hz was computed during quiet wakefulness (QW), light (stages 1 and 2) and deep (stages 3 and 4) nonrapid-eye-movement sleep (NREMS), and rapid-eye-movement sleep (REMS). A positive correlation between HP and the previous SBP values, which is the expected result of baroreflex feedback control, was observed in the sleep states but not in QW. In deep NREMS, the maximum CCF value was significantly higher than in any other state, suggesting the greatest baroreflex contribution to the coupling between HP and SBP. A negative correlation between HP and the subsequent SBP values was also observed in each state, consistent with the mechanical feed-forward action of HP on SBP and with central autonomic commands. The contribution of these mechanisms to the coupling between HP and SBP, estimated from the minimum CCF value, was significantly lower in deep NREMS than either in light NREMS or QW. These results indicate that the pattern of coupling between HP and SBP at low frequencies differs among wake-sleep states in human subjects, with deep NREMS entailing the highest feedback contribution of the baroreflex and a low effectiveness of feed-forward mechanisms.

scholarly journals Effect of capsinoids on energy metabolism in human subjects

2009 ◽  
Vol 103 (1) ◽  
pp. 38-42 ◽  
Author(s):  
Jose E. Galgani ◽  
Donna H. Ryan ◽  
Eric Ravussin
Keyword(s):  
Blood Pressure ◽  
Energy Metabolism ◽  
Metabolic Rate ◽  
Human Subjects ◽  
Acute Effect ◽  
Molecular Structures ◽  
Acute Effects ◽  
Axillary Temperature ◽  
Double Blind ◽  
Different Doses

Capsinoids are non-pungent compounds with molecular structures similar to capsaicin, which has accepted thermogenic properties. To assess the acute effect of a plant-derived preparation of capsinoids on energy metabolism, we determined RMR and non-protein respiratory quotient (NPRQ) after ingestion of different doses of the capsinoids. Thirteen healthy subjects received four doses of the capsinoids (1, 3, 6 and 12 mg) and placebo using a crossover, randomised, double-blind trial. After a 10 h overnight fast as inpatients, RMR was measured by indirect calorimetry for 45 min before and 120 min after ingesting capsinoids or placebo. Blood pressure and axillary temperature were measured before ( − 55 and − 5 min) and after (60 and 120 min) dosing. Before dosing, mean RMR was 6247 (se92) kJ/d and NPRQ was 0·86 (se0·01). At 120 min after dosing, metabolic rate and NPRQ remained similar across the four capsinoids and placebo doses. Capsinoids also had no influence on blood pressure or axillary temperature. Capsinoids provided in four doses did not affect metabolic rate and fuel partitioning in human subjects when measured 2 h after exposure. Longer exposure and higher capsinoids doses may be required to cause meaningful acute effects on energy metabolism.

scholarly journals Effects of corn silk aqueous extract on intraocular pressure of ocular hypertensive human subjects

2013 ◽  
Vol 72 (3) ◽  
Author(s):  
G.O. George ◽  
F.K. Idu ◽  
L.F.O. Obika
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Intraocular Pressure ◽  
Aqueous Extract ◽  
Zea Mays L ◽  
Human Subjects ◽  
Hypotensive Effect ◽  
Peak Effect ◽  
Corn Silk ◽  
Dose Dependent

Stigma/style of Zea mays L (Corn silk) has been documented to have hypotensive effect on blood pressure and to relieve oedema. However we are not aware of any literature on its hypotensive effect on intraocular pressure (IOP) of humans or animals. We studied the effects of water only, masked doses of corn silk aqueous extract (60 mg/kg, 130 mg/kg, 192.5 mg/kg and 260 mg/kg body weight) on the IOP and blood pressure (BP) of twenty normotensives and twenty ocular hypertensive subjects. Also we compared the effects of the varied doses of corn silk aqueous extract (CSAE) with masked doses (5 mg/kg and 10 mg/kg body weight) of acetazolamide on IOP of ocular hypertensive subjects only. The results showed that the last three doses of CSAE lowered IOP and BP significantly (p<0.001) within eight hours of administration. The peak effect on IOP was observed after four hours while the peak effect on BP was observed after three hours of administration in the normotensives and ocular hypertensive subjects likewise the hypotensive effect was dose-dependent. The results also showed that 130 mg/kg body weight of CSAE produced the same hypotensive effect on IOP of ocular hypertensive subjects as 5 mg/kg body weight of acetazolamide. Therefore CSAE may have some IOP lowering effects that require further investigation in the management of ocular hypertension. (S Afr Optom 2013 72(3) 133-143)

scholarly journals The Relation of Water and Sodium Excretion to Blood Pressure in Human Subjects

Circulation ◽  
1952 ◽  
Vol 6 (6) ◽  
pp. 919-924 ◽  
Author(s):  
D. M. GREEN ◽  
H. G. WEDELL ◽  
M. H. WALD ◽  
B. LEARNED
Keyword(s):  
Blood Pressure ◽  
Sodium Excretion ◽  
Human Subjects ◽  
Water And Sodium Excretion

Effects of muscle perfusion pressure on fatigue and systemic arterial pressure in human subjects

1999 ◽  
Vol 86 (3) ◽  
pp. 845-851 ◽  
Author(s):  
Julie R. Wright ◽  
D. I. McCloskey ◽  
Richard C. Fitzpatrick
Keyword(s):  
Blood Pressure ◽  
Perfusion Pressure ◽  
Human Subjects ◽  
Normal Subjects ◽  
Voluntary Contraction ◽  
Muscle Performance ◽  
Central Blood Pressure ◽  
Human Hand ◽  
Adductor Pollicis Muscle ◽  
Arterial Perfusion

The effects of changes in arterial perfusion across the physiological range on the fatigue of a working human hand muscle were studied in seven normal subjects. With the hand above heart level, subjects made repeated isometric contractions of the adductor pollicis muscle at 50% of maximal voluntary contraction in a 6-s on, 4-s off cycle. To assess fatigue, a maximal isometric twitch was elicited in each “off” period by electrical stimulation of the ulnar nerve. The experiment was repeated at least 2 days later with the hand at heart level. Five subjects showed faster fatigue with the arm elevated, and two subjects showed little difference in fatigue for the two conditions. Central blood pressure rose in proportion to fatigue for the subjects overall and returned quickly to its initial level afterwards. We conclude that human muscle fatigue can be increased by physiological reductions in perfusion pressure. Central blood pressure increases as the muscle fatigues, a response that may partially offset declining muscle performance.

scholarly journals Testing individual baroreflex responses to hypoxia-induced peripheral chemoreflex stimulation

2020 ◽  
Vol 30 (6) ◽  
pp. 531-540
Author(s):  
Hendrik Kronsbein ◽  
Darius A. Gerlach ◽  
Karsten Heusser ◽  
Alex Hoff ◽  
Fabian Hoffmann ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Pressor Response ◽  
Human Subjects ◽  
Arterial Oxygen Saturation ◽  
Recovery Period ◽  
Arterial Oxygen ◽  
Heart Rate Regulation ◽  
Peripheral Chemoreflex ◽  
Collective Influence

Abstract Introduction Baroreflexes and peripheral chemoreflexes control efferent autonomic activity making these reflexes treatment targets for arterial hypertension. The literature on their interaction is controversial, with suggestions that their individual and collective influence on blood pressure and heart rate regulation is variable. Therefore, we applied a study design that allows the elucidation of individual baroreflex–chemoreflex interactions. Methods We studied nine healthy young men who breathed either normal air (normoxia) or an air–nitrogen–carbon dioxide mixture with decreased oxygen content (hypoxia) for 90 min, with randomization to condition, followed by a 30-min recovery period and then exposure to the other condition for 90 min. Multiple intravenous phenylephrine bolus doses were applied per condition to determine phenylephrine pressor sensitivity as an estimate of baroreflex blood pressure buffering and cardiovagal baroreflex sensitivity (BRS). Results Hypoxia reduced arterial oxygen saturation from 98.1 ± 0.4 to 81.0 ± 0.4% (p < 0.001), raised heart rate from 62.9 ± 2.1 to 76.0 ± 3.6 bpm (p < 0.001), but did not change systolic blood pressure (p = 0.182). Of the nine subjects, six had significantly lower BRS in hypoxia (p < 0.05), two showed a significantly decreased pressor response, and three showed a significantly increased pressor response to phenylephrine in hypoxia, likely through reduced baroreflex buffering (p < 0.05). On average, hypoxia decreased BRS by 6.4 ± 0.9 ms/mmHg (19.9 ± 2.0 vs. 14.12 ± 1.6 ms/mmHg; p < 0.001) but did not change the phenylephrine pressor response (p = 0.878). Conclusion We applied an approach to assess individual baroreflex–chemoreflex interactions in human subjects. A subgroup exhibited significant impairments in baroreflex blood pressure buffering and BRS with peripheral chemoreflex activation. The methodology may have utility in elucidating individual pathophysiology and in targeting treatments modulating baroreflex or chemoreflex function.

scholarly journals Limb venous distension evokes sympathetic activation via stimulation of the limb afferents in humans

2012 ◽  
Vol 303 (4) ◽  
pp. H457-H463 ◽  
Author(s):  
Jian Cui ◽  
Patrick M. McQuillan ◽  
Cheryl Blaha ◽  
Allen R. Kunselman ◽  
Lawrence I. Sinoway
Keyword(s):  
Blood Pressure ◽  
Normal Saline ◽  
Sympathetic Nerve Activity ◽  
Human Subjects ◽  
Muscle Sympathetic Nerve Activity ◽  
Saline Infusion ◽  
Afferent Nerves ◽  
Postural Stress ◽  
Human Forearm ◽  
Blood Pressure Responses

We have recently shown that a saline infusion in the veins of an arterially occluded human forearm evokes a systemic response with increases in muscle sympathetic nerve activity (MSNA) and blood pressure. In this report, we examined whether this response was a reflex that was due to venous distension. Blood pressure (Finometer), heart rate, and MSNA (microneurography) were assessed in 14 young healthy subjects. In the saline trial ( n = 14), 5% forearm volume normal saline was infused in an arterially occluded arm. To block afferents in the limb, 90 mg of lidocaine were added to the same volume of saline in six subjects during a separate visit. To examine whether interstitial perfusion of normal saline alone induced the responses, the same volume of albumin solution (5% concentration) was infused in 11 subjects in separate studies. Lidocaine abolished the MSNA and blood pressure responses seen with saline infusion. Moreover, compared with the saline infusion, an albumin infusion induced a larger (MSNA: Δ14.3 ± 2.7 vs. Δ8.5 ± 1.3 bursts/min, P < 0.01) and more sustained MSNA and blood pressure responses. These data suggest that venous distension activates afferent nerves and evokes a powerful systemic sympathoexcitatory reflex. We posit that the venous distension plays an important role in evoking the autonomic adjustments seen with postural stress in human subjects.

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