Oral Contraceptives Alter Circadian Rhythm Parameters of Cortisol, Melatonin, Blood Pressure, Heart Rate, Skin Blood Flow, Transepidermal Water Loss, and Skin Amino Acids of Healthy Young Women

1996 ◽  
Vol 13 (3) ◽  
pp. 199-211 ◽  
Author(s):  
Alain E. Reinberg ◽  
Yvan Touitou ◽  
Étienne Soudant ◽  
Dominique Bernard ◽  
Roland Bazin ◽  
...  
2010 ◽  
Vol 299 (6) ◽  
pp. H1832-H1842 ◽  
Author(s):  
Azmy Faisal ◽  
Keith R. Beavers ◽  
Richard L. Hughson

Circadian rhythm has an influence on several physiological functions that contribute to athletic performance. We tested the hypothesis that circadian rhythm would affect blood pressure (BP) responses but not O2 uptake (V̇o2) kinetics during the transitions to moderate and heavy cycling exercises. Nine male athletes (peak V̇o2: 60.5 ± 3.2 ml·kg−1·min−1) performed multiple rides of two different cycling protocols involving sequences of 6-min bouts at moderate or heavy intensities interspersed by a 20-W baseline in the morning (7 AM) and evening (5 PM). Breath-by-breath V̇o2 and beat-by-beat BP estimated by finger cuff plethysmography were measured simultaneously throughout the protocols. Circadian rhythm did not affect V̇o2 onset kinetics determined from the phase II time constant (τ2) during either moderate or heavy exercise bouts with no prior priming exercise (τ2 moderate exercise: morning 22.5 ± 4.6 s vs. evening 22.2 ± 4.6 s and τ2 heavy exercise: morning 26.0 ± 2.7 s vs. evening 26.2 ± 2.6 s, P > 0.05). Priming exercise induced the same robust acceleration in V̇o2 kinetics during subsequent moderate and heavy exercise in the morning and evening. A novel finding was an overshoot in BP (estimated from finger cuff plethysmography) in the first minutes of each moderate and heavy exercise bout. After the initial overshoot, BP declined in association with increased skin blood flow between the third and sixth minute of the exercise bout. Priming exercise showed a greater effect in modulating the BP responses in the evening. These findings suggest that circadian rhythm interacts with priming exercise to lower BP during exercise after an initial overshoot with a greater influence in the evening associated with increased skin blood flow.


1986 ◽  
Vol 112 (2) ◽  
pp. 166-171 ◽  
Author(s):  
J. P. Bussien ◽  
R. C. Gaillard ◽  
J. Nussberger ◽  
B. Waeber ◽  
K. G. Hofbauer ◽  
...  

Abstract. The effect of vasopressin released during Finnish sauna on blood pressure, heart rate and skin blood flow was investigated in 12 healthy volunteers. Exposure to the hot air decrease body weight by 0.6 to 1.25 kg (mean = 0.8 kg, P < 0.001). One hour after the end of the sauna sessions, plasma vasopressin was higher (1.7 ± 0.2 pg/ml, P < 0.01 mean ± sem) than before the sauna (1.0 ± 0.1 pg/ml). No simultaneous change in plasma osmolality, plasma renin activity, plasma norepinephrine, epinephrine, cortisol, aldosterone, beta-endorphin and metenkephalin levels was observed. Despite the slight sauna-induced elevation in circulating vasopressin, intravenous injection of the specific vascular vasopressin antagonist d(CH2)5Tyr-(Me)AVP (5 μg/kg) 1 h after the sauna had no effect on blood pressure, heart rate or skin blood flow. These data suggest that vasopressin released into the circulation during a sauna session reaches concentrations which are not high enough to interfere directly with vascular tone.


1961 ◽  
Vol 201 (1) ◽  
pp. 109-111 ◽  
Author(s):  
Noel M. Bass ◽  
Vincent V. Glaviano

Heart rate, mean blood pressure, adrenal blood flow, and adrenal plasma adrenaline and noradrenaline were compared before and after ligation of the anterior descending coronary artery in dogs anesthetized with chloralose. One group of 12 dogs responded to acute coronary occlusion with a sudden and marked decrease in mean blood pressure (mean, 31%) and heart rate (mean, 18%) followed by an early onset (mean, 227 sec) of ventricular fibrillation. Another group of nine dogs responded with slight decreases in mean blood pressure (mean, 13%) and heart rate (mean, 5%), during which time ventricular fibrillation occurred late (mean, 30 min) or not at all. While the two groups were statistically different in mean blood pressure and heart rate, the minute output of adrenal catecholamines in either group was not found to be related to the early or late occurrence of ventricular fibrillation.


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