Ventilation, heart rate and respiratory gas exchange in the crayfishAustropotamobius pallipes (Lereboullet) submerged in normoxic water and following 3 h exposure in air at 15�C

1980 ◽  
Vol 138 (1) ◽  
pp. 67-78 ◽  
Author(s):  
E. W. Taylor ◽  
Mich�le G. Wheatly
Keyword(s):  
Heart Rate ◽  
Gas Exchange ◽  
Respiratory Gas Exchange

scholarly journals Coca chewing for exercise: hormonal and metabolic responses of nonhabitual chewers

1996 ◽  
Vol 81 (5) ◽  
pp. 1901-1907 ◽  
Author(s):  
Roland Favier ◽  
Esperanza Caceres ◽  
Laurent Guillon ◽  
Brigitte Sempore ◽  
Michel Sauvain ◽  
...  
Keyword(s):  
Heart Rate ◽  
Gas Exchange ◽  
Oxygen Uptake ◽  
Metabolic Responses ◽  
Physiological Data ◽  
Respiratory Gas Exchange ◽  
Gum Chewing ◽  
Arterial Blood ◽  
Before And After ◽  
Exercise Induced

Favier, Roland, Esperanza Caceres, Laurent Guillon, Brigitte Sempore, Michel Sauvain, Harry Koubi, and Hilde Spielvogel. Coca chewing for exercise: hormonal and metabolic responses of nonhabitual chewers. J. Appl. Physiol. 81(5): 1901–1907, 1996.—To determine the effects of acute coca use on the hormonal and metabolic responses to exercise, 12 healthy nonhabitual coca users were submitted twice to steady-state exercise (∼75% maximal O2 uptake). On one occasion, they were asked to chew 15 g of coca leaves 1 h before exercise, whereas on the other occasion, exercise was performed after 1 h of chewing a sugar-free chewing gum. Plasma epinephrine, norepinephrine, insulin, glucagon, and metabolites (glucose, lactate, glycerol, and free fatty acids) were determined at rest before and after coca chewing and during the 5th, 15th, 30th, and 60th min of exercise. Simultaneously to these determinations, cardiorespiratory variables (heart rate, mean arterial blood pressure, oxygen uptake, and respiratory gas exchange ratio) were also measured. At rest, coca chewing had no effect on plasma hormonal and metabolic levels except for a significantly reduced insulin concentration. During exercise, the oxygen uptake, heart rate, and respiratory gas exchange ratio were significantly increased in the coca-chewing trial compared with the control (gum-chewing) test. The exercise-induced drop in plasma glucose and insulin was prevented by prior coca chewing. These results contrast with previous data obtained in chronic coca users who display during prolonged submaximal exercise an exaggerated plasma sympathetic response, an enhanced availability and utilization of fat (R. Favier, E. Caceres, H. Koubi, B. Sempore, M. Sauvain, and H. Spielvogel. J. Appl. Physiol. 80: 650–655, 1996). We conclude that, whereas coca chewing might affect glucose homeostasis during exercise, none of the physiological data provided by this study would suggest that acute coca chewing in nonhabitual users could enhance tolerance to exercise.

Effect of O2 and CO2 in N2, He, and SF6 on chick embryo blood pressure and heart rate

1981 ◽  
Vol 51 (4) ◽  
pp. 1017-1022 ◽  
Author(s):  
H. Tazawa
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Gas Exchange ◽  
Chick Embryo ◽  
Sulfur Hexafluoride ◽  
Inert Gases ◽  
Maximum Pressure ◽  
Chick Embryos ◽  
Respiratory Gas Exchange ◽  
Made In

Arterial pressure of chick embryos was measured electromanometrically to investigate the effect of altered gaseous environments on blood pressure (BP) and heart rate (HR). The experiments were made in eggs incubated for 14–16 days at 38 degrees C without impeding the diffusive respiratory gas exchange through the shell and chorioallantois. In air, the HR was counted 260–270 beats/min and the BP increased from 14/7 Torr at day 14 to 21/12 Torr at day 16. Both the BP and HR decreased with hypoxia, whereas hyperoxia affected a slight increase in BP and little change in HR. Hypercapnia decreased the HR and tended to enhance a systolic maximum pressure. The effect of hypoxia was augmented markedly in the presence of hypercapnia and vice versa. When N2 was replaced with helium (He), the effect of hypoxia was mitigated significantly. On the contrary, replacement of N2 with sulfur hexafluoride (SF6) augmented the effect of hypoxia. Because the respiratory gas exchange of the egg takes place by diffusion through the shell and chorioallantoic capillaries, the effect of He and SF6 atmospheres on BP and HR is attributed to an altered diffusivity of O2 and CO2 in these inert gases.

Respiratory Gas Exchange and Growth of Bonin Petrel Embryos

1982 ◽  
Vol 55 (2) ◽  
pp. 162-170 ◽  
Author(s):  
Ted N. Pettit ◽  
Gilbert S. Grant ◽  
G. Causey Whittow ◽  
Hermann Rahn ◽  
Charles V. Paganelli
Keyword(s):  
Gas Exchange ◽  
Respiratory Gas Exchange

scholarly journals Exercise chronotropic incompetence phenotypes the level of cardiovascular risk and exercise gas exchange impairment in the general population. An analysis of the Euro-EX prevention trial

2019 ◽  
Vol 27 (5) ◽  
pp. 526-535 ◽  
Author(s):  
Pietro Laforgia ◽  
Francesco Bandera ◽  
Eleonora Alfonzetti ◽  
Marco Guazzi
Keyword(s):  
Heart Rate ◽  
Cardiovascular Risk ◽  
Gas Exchange ◽  
Left Ventricular ◽  
Prevention Trial ◽  
Volume Index ◽  
Maximal Heart Rate ◽  
Heart Rate Reserve ◽  
Peak Heart Rate ◽  
Apparently Healthy

Background Chronotropic insufficiency (CI) is defined as the inability of the heart to increase its rate commensurate with increased demand. Exercise CI is an established predictor of major adverse cardiovascular events in patients with cardiovascular diseases. Aim The aim of this study was to evaluate how exercise CI phenotypes different levels of cardiovascular risk and how it may better perform in defining cardiovascular risk when analysed in the context of cardiopulmonary exercise test (CPET)-derived measures and standard echocardiography in a healthy population with variable cardiovascular risk profile. Methods Apparently healthy individuals ( N = 702, 53.8% females) with at least one major cardiovascular risk factor (MCVRF; hypertension, diabetes, tabagism, dyslipidaemia, body mass index > 25), enrolled in the Euro-EX prevention trial, underwent CPET. CI was defined as the inability to reach 80% of the chronotropic index, that is, the ratio of peak heart rate – rest heart rate/peak heart rate – age predicted maximal heart rate (AMPHR: 220 – age), they were divided into four groups according to the heart rate reserve (<80%>) and respiratory gas exchange ratio (RER; < 1.05>) as a marker of achieved maximal performance. Subjects with a RER < 1.05 ( n = 103) were excluded and the final population ( n = 599) was divided into CI group ( n = 472) and no-CI group ( n = 177). Results Compared with no-CI, CI subjects were more frequently females with a history of hypertension in a high rate. CI subjects also exhibited a significantly lower peak oxygen uptake (VO2) and circulatory power and an echocardiographic pattern indicative of higher left atrial volume index and left ventricular mass index. An inverse stepwise relationship between heart rate reserve and number of MCVRFs was observed (one MCVRF: 0.71 ± 0.23; two MCVRFs: 0.68 ± 0.24, three MCVRFs: 0.64 ± 0.20; four MCVRFs: 0.64 ± 0.23; five MCVRFs: 0.57 ± 18; p < 0.01). In multivariate analysis the only variable found predicting CI was peak VO2 ( p < 0.05; odds ratio 0.91; confidence interval 0.85–0.97). Conclusions In a population of apparently healthy subjects, exercise CI is common and phenotypes the progressive level of cardiovascular risk by a tight relationship with MCVRFs. CI patients exhibit some peculiar abnormal exercise gas exchange patterns (lower peak VO2 and exercise oscillatory ventilation) and echo-derived measures (higher left atrium size and left ventricle mass) that may well anticipate evolution toward heart failure.

scholarly journals Influence of exercise modality on agreement between gas exchange and heart rate variability thresholds

2014 ◽  
Vol 47 (8) ◽  
pp. 706-714 ◽  
Author(s):  
F.A. Cunha ◽  
R.A. Montenegro ◽  
A.W. Midgley ◽  
F. Vasconcellos ◽  
P.P. Soares ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Gas Exchange ◽  
Exercise Modality
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