Electrocortical activity, breathing and body movements, heart rate and blood pressure during mechanical pulmonary ventilation in fetal sheep

1985 ◽  
Vol 19 (5) ◽  
pp. 329-330
Author(s):  
C.E. Blanco ◽  
C.B. Martin ◽  
A.J. Crevels ◽  
T.H.M. Arts
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Pulmonary Ventilation ◽  
Body Movements ◽  
Fetal Sheep ◽  
Electrocortical Activity

scholarly journals Effects of Three Months of Detraining on the Health Profile of Older Women after a Multicomponent Exercise Program

2019 ◽  
Vol 16 (20) ◽  
pp. 3881 ◽  
Author(s):  
Luis Leitão ◽  
Ana Pereira ◽  
Mauro Mazini ◽  
Gabriela Venturini ◽  
Yuri Campos ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Older Women ◽  
Repeated Measures ◽  
Pulmonary Ventilation ◽  
Exercise Program ◽  
Control Group ◽  
Health Profile ◽  
Older Individuals ◽  
Negative Effects

Physical exercise results in very important benefits including preventing disease and promoting the quality of life of older individuals. Common interruptions and training cessation are associated with the loss of total health profile, and specifically cardiorespiratory fitness. Would detraining (DT) promote different effects in the cardiorespiratory and health profiles of trained and sedentary older women? Forty-seven older women were divided into an experimental group (EG) and a control group (CG) (EG: n = 28, 70.3 ± 2.3 years; CG: n = 19, 70.1 ± 5.6 years). Oxygen uptake (VO2) and health profile assessments were conducted after the exercise program and after three months of detraining. The EG followed a nine-month multicomponent exercise program before a three-month detraining period. The CG maintained their normal activities. Repeated measures ANOVA showed significant increases in total heath and VO2 (p < 0.01) profile over a nine-month exercise period in the EG and no significant increases in the CG. DT led to greater negative effects on total cholesterol (4.35%, p < 0.01), triglycerides (3.89%, p < 0.01), glucose (4.96%, p < 0.01), resting heart rate (5.15%, p < 0.01), systolic blood pressure (4.13%, p < 0.01), diastolic blood pressure (3.38%, p < 0.01), the six-minute walk test (7.57%, p < 0.01), Pulmonary Ventilation (VE) (10.16%, p < 0.01), the Respiratory Exchange Ratio (RER) (9.78, p < 0.05), and VO2/heart rate (HR) (16.08%, p < 0.01) in the EG. DT may induce greater declines in total health profile and in VO2, mediated, in part, by the effectiveness of multicomponent training particularly developed for older women.

Site of central chemosensitivity in fetal sheep

1975 ◽  
Vol 39 (1) ◽  
pp. 1-6 ◽  
Author(s):  
A. H. Jansen ◽  
V. Chernick
Keyword(s):  
Blood Pressure ◽  
Spinal Cord ◽  
Heart Rate ◽  
Respiratory Response ◽  
Fetal Sheep ◽  
Central Chemosensitivity ◽  
Cord Clamping ◽  
Chemosensitive Areas ◽  
Ventral Medullary Surface ◽  
Histotoxic Hypoxia

The heart rate, blood pressure, and respiratory response to topically applied cyanide on the ventrolateral medullary surface and upper spinal cord was studied on exteriorized sinaortic-denervated fetal lambs under pentobarbital anesthesia. On all sites tested cyanide produced a rapid increase in heart rate and blood pressure (P smaller than 0.05) which was most pronounced from the area adjacent to the nerve roots IX to XI (mean 32%). Respiratory efforts consisting of 1–8 gasps were induced in half the applications to the medulla but never when the pledgets were applied to the spinal cord. The mean delay to response was 43 s (range 13–102 s). After cautery of the chemosensitive areas, topical application of cyanide failed to stimulate gasping, whereas intravenous cyanide or cord clamping still produced a vigorous respiratory response. It is concluded that sympathetic stimulation of the heart and blood vessels can originate centrally in response to local histotoxic hypoxia of the ventral medulla and upper spinal cord. Furthermore, it is proposed that in the apneic fetus histotoxic hypoxia of the medulla initiates respiration possibly by stimulating a special gasping mechanism which is separate from the respiratory center responsible for rhythmic breathing after birth. The responsible neurons must be located at least 2 mm beneath the ventral medullary surface.

Effects of lidocaine on heart rate, blood pressure, and electrocorticogram in fetal sheep

1974 ◽  
Vol 118 (7) ◽  
pp. 935-949 ◽  
Author(s):  
K. Teramo ◽  
N. Benowitz ◽  
M.A. Heymann ◽  
K. Kahanpää ◽  
A. Siimes ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Fetal Sheep

Blood pressure and heart rate in the ovine fetus: ontogenic changes and effects of fetal adrenalectomy

1999 ◽  
Vol 276 (1) ◽  
pp. H248-H256 ◽  
Author(s):  
Nobuya Unno ◽  
Chi H. Wong ◽  
Susan L. Jenkins ◽  
Richard A. Wentworth ◽  
Xiu-Ying Ding ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Plasma Cortisol ◽  
Time Windows ◽  
Late Gestation ◽  
Fetal Sheep ◽  
Fetal Plasma ◽  
Long Term Study ◽  
Arterial Blood ◽  
Ovine Fetus

Ontogenic changes in baseline and 24-h rhythms of fetal arterial blood pressure (FABP) and heart rate (FHR) and their regulation by the fetal adrenal were studied in 18 fetal sheep chronically instrumented at 109–114 days gestation (GA). In the long-term study, FABP and FHR were continuously recorded from 120 days GA to spontaneous term labor (>145 days GA) in five animals. Peak times (PT) and amplitudes (Amp) of cosinor analysis were compared at 120–126, 127–133, and 134–140 days GA. Consistent, significant linear increases in FABP and linear decreases in FHR were observed in all fetuses. Significant 24-h rhythms in FABP and FHR were observed during all the time windows. In the adrenalectomy study, to test the hypothesis that fetal cortisol plays a key role in cardiovascular maturation, fetal adrenals were removed in eight animals (ADX); sham fetal adrenalectomy was performed on five animals (Con). Cortisol (4 μg/min) was infused intravenously in four ADX fetuses from day 7postsurgery for 7 days (ADX+F). No significant changes in PT and Amp in FABP and FHR were observed. Plasma cortisol levels remained low in Con and ADX fetuses (<4.9 ng/ml). Cortisol infusion increased fetal plasma cortisol to 22.3 ± 3.2 ng/ml (mean ± SE) on day 13 in ADX+F fetuses. FABP increased in control and ADX+F but not ADX fetuses; FHR decreased in control and ADX but rose in ADX+F fetuses. These results suggest that, in chronically instrumented fetal sheep at late gestation, 1) increases in FABP and decreases in FHR are maintained consistently from 120 to 140 days GA, with distinct 24-h rhythms, the PT and Amp of which remain unchanged, and 2) the physiological increase in FABP is dependent on the fetal adrenal; bilateral removal of the fetal adrenals does not prevent the ability of cortisol to produce a sustained increase in FABP.

Prevention of hypoinsulinemia modifies catecholamine effects in fetal sheep

2000 ◽  
Vol 278 (5) ◽  
pp. R1171-R1181 ◽  
Author(s):  
John M. Bassett ◽  
Clifford Hanson
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Insulin Secretion ◽  
Metabolic Activity ◽  
Plasma Glucose ◽  
Insulin Infusion ◽  
Prolonged Infusion ◽  
Fetal Sheep ◽  
Intravenous Insulin ◽  
Arterial Blood

Increased epinephrine (Epi) and norepinephrine (NE) production plays an important role in fetal adaptation to reduced oxygen and/or nutrient availability, inhibiting insulin secretion and slowing growth to support more essential processes. To assess the importance of hypoinsulinemia for the efficacy of catecholamines, normoinsulinemia was restored by intravenous insulin infusion (0.18 mU ⋅ kg− 1 ⋅ min− 1) during prolonged infusion of either Epi (0.25–0.35 μg ⋅ kg− 1 ⋅ min− 1for 12 days, n = 7) or NE (0.5–0.7 μg ⋅ kg− 1 ⋅ min− 1for 7 days, n = 6) into normoxemic fetuses in twin-pregnant ewes, from 125–127 days of gestation. Insulin infusion for 8 days during Epi infusion or for 4 days during NE infusion decreased arterial blood pressure, O2 content, and plasma glucose, but increased heart rate significantly (all P <0.05), despite continuation of Epi or NE infusion. Cessation of insulin infusion reversed these changes. Estimated growth of fetuses infused with insulin during Epi or NE infusion (55 ± 13.9 and 83 ± 15.2 g/day) did not differ significantly from that of untreated controls (72 ± 15.4 g/day, n = 6). Growth of selected muscles and hindlimb bones was not altered either. Restoration of normoinsulinemia evidently counteracts the redistribution of metabolic activity and decreased anabolism brought about by Epi or NE in the fetus. Inhibition of insulin secretion by Epi and NE, therefore, appears essential for the efficacy of catecholamine action in the fetus.

Ventilatory responses to carboxyhaemoglobinaemia and hypoxic hypoxia in Bufo paracnemis.

1995 ◽  
Vol 198 (6) ◽  
pp. 1417-1421 ◽  
Author(s):  
L G Branco ◽  
M L Glass
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Pulmonary Ventilation ◽  
Hypoxic Hypoxia ◽  
Ventilatory Responses ◽  
Fractional Concentration ◽  
O2 Partial Pressure ◽  
Arterial Ph ◽  
Bicarbonate Infusion ◽  
Arterial Po2

The modality of the O2 drive to breathe was evaluated in unanaesthetized Bufo paracnemis. Carbon monoxide (CO) hypoxia was applied to reduce CaO2 (arterial O2 content). Arterial PO2 (PaO2) was reduced through inspiration of hypoxic gas mixtures (hypoxic hypoxia). Measurements included pulmonary ventilation, CaO2, PaO2, pHa, blood pressure and heart rate. Application of fractional concentrations of CO equivalent to 0.001 reduced CaO2 from 11.6 +/- 1.2 to 8.6 +/- 0.7 vol% (mean +/- S.E.M., N = 6) without any effect on heart rate, blood pressure or ventilation. Inspiration of fractional concentrations of CO equivalent to 0.01 reduced CaO2 to 5.1 +/- 0.7 vol%, which was accompanied by increased ventilation. This response, however, correlated with a decreased arterial pH. The effect of a fractional concentration of CO of 0.01 on ventilation was abolished by compensation of pH through bicarbonate infusion. Consequently, carboxyhaemoglobinaemia per se failed to increase ventilation. By contrast, reductions of PaO2 clearly stimulated ventilation, which indicates that O2 partial pressure provides the principal O2 stimulus to breathe in Bufo paracnemis.

Is baroreflex control of sympathetic activity and heart rate active in the preterm fetal sheep?

2009 ◽  
Vol 296 (3) ◽  
pp. R603-R609 ◽  
Author(s):  
Lindsea C. Booth ◽  
Simon C. Malpas ◽  
Carolyn J. Barrett ◽  
Sarah-Jane Guild ◽  
Alistair J. Gunn ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Pressure Control ◽  
Autonomic Response ◽  
Nerve Activity ◽  
Baroreflex Control ◽  
Fetal Sheep ◽  
Arterial Blood

The arterial baroreflex is a fundamental reflex that buffers rapid changes in arterial blood pressure (BP) via regulation of the heart rate and sympathetic nerve activity to the vasculature. In adults a sigmoidal relationship between BP and both heart rate and sympathetic nerve activity is well documented. Its role in blood pressure control before birth is unclear. Preterm babies have a high incidence of low BP, especially in the first few days of life, which could be related, in part, to immaturity of the baroreflex. In the present study, we investigated the baroreflex control of fetal heart rate and renal sympathetic nerve activity (RSNA) in preterm fetal sheep in utero (102 ± 1 days of gestation; term 140 days). Phenylephrine was associated with a significant increase in BP from 38 ± 2 to 58 ± 3 mmHg and a decrease in heart rate (HR) from 177 ± 4 to 116 ± 8 beats per minute (bpm). Sodium nitroprusside was associated with a significant fall in BP from 38 ± 2 to 26 ± 1 mmHg and an increase in HR from 182 ± 4 to 274 ± 8 bpm. However, the time between the 50% changes in BP and HR was significantly greater after hypotension than hypertension (31 ± 8 s vs. 14 ± 5 s, P < 0.05). No significant changes in RSNA occurred with either stimulus. This suggests that there are different maturational tempos for the components of the central autonomic response to altered blood pressure.

scholarly journals Blockade of PGHS-2 inhibits the hypothalamus-pituitary-adrenal axis response to cerebral hypoperfusion in the sheep fetus

2009 ◽  
Vol 296 (6) ◽  
pp. R1813-R1819 ◽  
Author(s):  
Charles E. Wood ◽  
Melanie Powers Fraites ◽  
Maureen Keller-Wood
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Nervous System ◽  
Arterial Pressure ◽  
Fetal Heart Rate ◽  
Fetal Heart ◽  
Cerebral Hypoperfusion ◽  
Fetal Sheep ◽  
Intracerebroventricular Infusion ◽  
Hpa Response

Decreases in fetal blood pressure stimulate homeostatic stress responses that help return blood pressure to normal levels. Fetal hypothalamus-pituitary-adrenal (HPA) axis responses to hypotension are mediated by chemoreceptor and baroreceptor reflexes and ischemia of the fetal central nervous system. Indomethacin, a nonselective inhibitor of prostaglandin endoperoxide synthase (PGHS)-1 and -2, attenuates the HPA response to hypotension in the fetus. The present study was designed to test the hypothesis that selective inhibition of PGHS-2 also inhibits the HPA response to cerebral hypoperfusion. We studied 13 chronically catheterized fetal sheep (126–136 days gestation). Five fetal sheep were subjected to intracerebroventricular infusion of nimesulide (0.01 mg/day), a specific inhibitor of PGHS-2, and eight were treated with vehicle (DMSO in water) for 5 days. Each fetus was subjected to a 10-min period of brachiocephalic occlusion, which decreased carotid arterial pressure ∼75% and reflexively increased fetal plasma concentrations of ACTH, POMC, cortisol, and femoral arterial pressure, and decreased fetal heart rate. Nimesulide significantly inhibited the ACTH response to the BCO, while significantly augmenting the reflex cardiovascular response and altering fetal heart rate variability consistent with increased sympathetic nervous system activity. The results of this study demonstrate that the activity of PGHS-2 in the brain is a necessary component of the fetal HPA response to cerebral hypoperfusion in the late-gestation fetal sheep. These results are consistent with those of recent study, in which we demonstrated that the preparturient increase in fetal ACTH secretion depends upon PGHS-2 activity within the fetal brain.

Physiological reactions of men and women during muscular activity and recovery in various environments

1961 ◽  
Vol 16 (1) ◽  
pp. 133-140 ◽  
Author(s):  
L. Brouha ◽  
P. E. Smith ◽  
R. De Lanne ◽  
M. E. Maxfield
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Weight Loss ◽  
Body Temperature ◽  
Diastolic Pressure ◽  
Pulmonary Ventilation ◽  
Muscular Activity ◽  
Work Load ◽  
Men And Women ◽  
Dry Conditions

Men and women performing a standard exercise were studied in three environments. Pulmonary ventilation, O2 consumption, CO2 elimination, heart rate, blood pressure, body temperature and weight loss were recorded. Pulmonary ventilation was usually decreased in the warm-dry environment and increased in the warm-humid. Oxygen consumption was significantly lower in the warm-dry environment than at room temperature. The pattern of changes of these two functions was similar for both sexes. Respiratory exchange ratios were not influenced by sex, but were higher in the warm-dry environment. Increase in body temperature was found only in the warm-humid environment, with a smaller weight loss than in warm-dry conditions. Systolic blood pressure was influenced by work load but not by environments. Diastolic pressure varied little for both sexes under all conditions. Heart rate was significantly influenced by sex and environment, being highest for the women in the warm-humid conditions. Cardiac cost increased and cardiac efficiency decreased in both warm surroundings, more so for women than for men. Submitted on May 16, 1960

scholarly journals The effect of sets and repetitions of the spirometer by flow in cardiorespiratory parameters

2014 ◽  
Vol 27 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Bruno Martinelli ◽  
Giovana Damasceno e Souza ◽  
Mariana Dela Coleta Ricci ◽  
Camila Gimenes ◽  
Marta Helena Souza De Conti ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Statistical Analysis ◽  
Young People ◽  
Vital Capacity ◽  
Pulmonary Ventilation ◽  
Minute Volume ◽  
Maximal Inspiratory Pressure ◽  
Sample Group ◽  
Tukey Test

Introduction The incentive spirometer helps pulmonary ventilation and the cardiorespiratory changes of its use are controversial. Objective To evaluate the effect of sets and repetitions on cardiorespiratory parameters using a spirometer alinear flow (SAF). The sample group consisted of 50 young people, healthy and sedentary. The evaluated parameters were: systolic blood pressure (SBP), diastolic (DBP), heart rate (HR), respiratory rate (RR), oxygen saturation (SaO2), minute volume (VE), tidal volume (VT), vital capacity (VC), maximal inspiratory pressure (Pimax), maximal expiratory pressure (Pemax), and peak expiratory flow (PEF). The moments of study were: initial evaluations (M1); 3 sets of 10 repetitions using SAF (M2); 3 sets of 15 repetitions using SAF (M3); and final evaluation (M4). Statistical analysis was made by t test, ANOVA and Tukey test (p < 0.05). Results SBP and HR decreased in M2 after the 2nd set. In the 3rd set, SBP and RR decreased. Comparing the initial and final variables in M2, SBP and RR decreased, and Pemax increased. After 1st set in M3, SBP and SaO2 decreased. The 2nd set: SBP, HR, RR, and SaO2 decreased. After the 3rd set: SBP, HR, SaO2, and RR decreased. Comparing the initial and final variables in M3, SBP, HR, RR decreased, and Pimax and Pemax increased. Comparing M4 to M1, Pimax, Pemax, and VC increased, and RR decreased. Conclusion There are changes in cardiorespiratory parameters after the use of a spirometer alinear flow, especially in the sets with more repetitions.

Sign in / Sign up

Export Citation Format

Share Document