Heart rate control in diabetic rabbits: blunted response to isoproterenol

To study the effects of chronic diabetes on heart rate and adrenergic responsiveness we compared unanesthetized diabetic rabbits, 10-13 mo after alloxan monohydrate injection, to age-matched controls. There were no significant differences found between groups for body or heart weight. Both resting and intrinsic heart rate (the latter obtained after atropine sulfate and propranolol HCl) were similar. In addition, serum and left ventricular epinephrine and norepinephrine concentrations as well as left ventricular beta-receptor density and affinity were unchanged in diabetic animals. Heart rate responses to isoproterenol were blunted in diabetics at the three highest doses. Base-line mean blood pressure was modestly lower in diabetic rabbits, and parallel declines in pressure for both groups were observed in response to isoproterenol. The diminished heart rate response to isoproterenol in diabetic rabbits may be due to diminished myocardial sensitivity to catecholamines, possibly combined with altered baroreceptor reflexes. These experiments may provide an explanation for the blunted heart rate response to exercise described in human diabetics.

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Heart Rate Response to Exercise

Ellestad's Stress Testing ◽

10.1093/med/9780190225483.003.0022 ◽

2018 ◽

pp. 437-445

Author(s):

Gregory S. Thomas

Keyword(s):

Heart Rate ◽

Physical Fitness ◽

Sample Size ◽

Older Persons ◽

Heart Rate Response ◽

Large Sample Size ◽

Maximum Heart Rate ◽

Large Sample ◽

Response To Exercise

The chapter Heart Rate Response to Exercise reviews the studies performed to estimate a patient’s maximum predicted heart rate. While the commonly used formula (220 – age), developed in 1971, is easy to remember, it underestimates the actual maximum heart rate in older persons. Studies of large sample size have found the maximum heart rate to be relatively independent of sex and physical fitness but to incrementally decline with age. The decrease with age is less than 1 beat per minute per year, however. A more accurate and recommended formula is [(208) – (0.7)(age)] as developed by Tanaka and colleagues.

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Assessment of Validity and Reliability of the 1-Minute Sit-to-Stand Test to Measure the Heart Rate Response to Exercise in Healthy Children

JAMA Pediatrics ◽

10.1001/jamapediatrics.2019.1084 ◽

2019 ◽

Vol 173 (7) ◽

pp. 692 ◽

Cited By ~ 3

Author(s):

Gregory Reychler ◽

Nicolas Audag ◽

Natalia Morales Mestre ◽

Gilles Caty

Keyword(s):

Heart Rate ◽

Heart Rate Response ◽

Healthy Children ◽

Validity And Reliability ◽

Stand Test ◽

Sit To Stand ◽

Response To Exercise

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THE HEART RATE RESPONSE TO EXERCISE IN HEALTHY WOMEN AGED 13 TO 88

Southern Medical Journal ◽

10.1097/00007611-199209001-00120 ◽

1992 ◽

Vol 85 (Supplement) ◽

pp. 3S-45

Author(s):

Allen F. Bowyer ◽

Rosemary A. Thomas

Keyword(s):

Heart Rate ◽

Heart Rate Response ◽

Healthy Women ◽

Response To Exercise

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Abnormal heart rate response to exercise in vasospastic angina: Pathophysiologic mechanism in the provocation of coronary spasm

American Heart Journal ◽

10.1016/0002-8703(84)90618-5 ◽

1984 ◽

Vol 108 (2) ◽

pp. 316-326 ◽

Cited By ~ 5

Author(s):

Iwao Sato ◽

Katsuro Shimomura ◽

Yasuhiro Hasegawa ◽

Tohru Ohe ◽

Mokuo Matsuhisa ◽

...

Keyword(s):

Heart Rate ◽

Heart Rate Response ◽

Coronary Spasm ◽

Vasospastic Angina ◽

Pathophysiologic Mechanism ◽

Response To Exercise

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Effect of lung transplantation on heart rate response to exercise

Heart & Lung ◽

10.1016/j.hrtlng.2015.01.014 ◽

2015 ◽

Vol 44 (3) ◽

pp. 246-250 ◽

Cited By ~ 1

Author(s):

Hilary F. Armstrong ◽

Jose Gonzalez-Costello ◽

Wilawan Thirapatarapong ◽

Ulrich P. Jorde ◽

Matthew N. Bartels

Keyword(s):

Heart Rate ◽

Lung Transplantation ◽

Heart Rate Response ◽

Response To Exercise

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Aortic blood flow in dogs during treadmill exercise

Journal of Applied Physiology ◽

10.1152/jappl.1959.14.5.809 ◽

1959 ◽

Vol 14 (5) ◽

pp. 809-812 ◽

Cited By ~ 33

Author(s):

Dean L. Franklin ◽

Richard M. Ellis ◽

R. F. Rushmer

Keyword(s):

Heart Rate ◽

Blood Flow ◽

Treadmill Exercise ◽

Essential Feature ◽

Left Ventricular ◽

Cardiac Response ◽

Aortic Blood Flow ◽

Direct Measurements ◽

Flow Through ◽

Response To Exercise

Instantaneous blood flow through the thoracic aorta was monitored continuously during spontaneous activity in intact dogs by means of a new, pulsed, ultrasonic flowmeter. Integrated flow per stroke, accumulated flow per unit time and heart rate were simultaneously derived by means of electronic computers. During treadmill exercise at 3 mph on a 5% grade, the heart rate increased by two- or threefold, but the aortic flow per stroke was only slightly increased. This observation was confirmed by direct measurements, of left ventricular diameter. An increase in stroke volume is not an essential feature of the cardiac response to exercise in these experiments. Submitted on December 15, 1958

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System analysis of heart rate control in man

Journal of Applied Physiology ◽

10.1152/jappl.1976.41.5.790 ◽

1976 ◽

Vol 41 (5) ◽

pp. 790-796 ◽

Cited By ~ 6

Author(s):

I. Sato ◽

Y. Hasegawa ◽

K. Hotta

Keyword(s):

Heart Rate ◽

Weight Function ◽

Rate Control ◽

Cross Correlation ◽

System Analysis ◽

Heart Rate Response ◽

Control Function ◽

Heart Rate Control ◽

Young Males ◽

Response To Exercise

The dynamic property of the heart rate response to exercise was determined and expressed in the frequency domain to establish a method of examiningcardiovascular control function. The response of heart rate to a stimulus was measured at 5-s intervals in nine healthy young volunteers. The stimulusconsisted of several runs of two-step exercise practiced in semirandom sequence for 19 min. The weight function of the system was estimated from autocorrelation function of the input signal and cross-correlation function between the input and output signals. The weight function was transformed into a transfer function and its Bode plot diagram was drawn. From the diagram, four dynamic parameters were determined. These parameters are as follows: Kis a constant showing the theoretical steady-state increment of heart rate,and T1, T2, T3 are time constants. The values obtained in the present experiment with the healthy young males were: K 46.0 +/- 14.6 beats, T1, 2.12 +/- 0.44, T2, 1.12 +/- 0.16, and T3 0.70 +/- 0.07 min.

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Alterations of heart function and Na+-K+-ATPase activity by etomoxir in diabetic rats

Journal of Applied Physiology ◽

10.1152/jappl.1999.86.3.812 ◽

1999 ◽

Vol 86 (3) ◽

pp. 812-818 ◽

Cited By ~ 16

Author(s):

Kiminori Kato ◽

Donald C. Chapman ◽

Heinz Rupp ◽

Anton Lukas ◽

Naranjan S. Dhalla

Keyword(s):

Heart Rate ◽

Cardiac Function ◽

Atpase Activity ◽

Binding Sites ◽

Heart Function ◽

Diabetic Rats ◽

Left Ventricular ◽

Carnitine Palmitoyltransferase ◽

Heart Weight ◽

High Affinity

To examine the role of changes in myocardial metabolism in cardiac dysfunction in diabetes mellitus, rats were injected with streptozotocin (65 mg/kg body wt) to induce diabetes and were treated 2 wk later with the carnitine palmitoyltransferase inhibitor (carnitine palmitoyltransferase I) etomoxir (8 mg/kg body wt) for 4 wk. Untreated diabetic rats exhibited a reduction in heart rate, left ventricular systolic pressure, and positive and negative rate of pressure development and an increase in end-diastolic pressure. The sarcolemmal Na+-K+-ATPase activity was depressed and was associated with a decrease in maximal density of binding sites (Bmax) value for high-affinity sites for [3H]ouabain, whereas Bmax for low-affinity sites was unaffected. Treatment of diabetic animals with etomoxir partially reversed the depressed cardiac function with the exception of heart rate. The high serum triglyceride and free fatty acid levels were reduced, whereas the levels of glucose, insulin, and 3,3′,-5-triiodo-l-thyronine were not affected by etomoxir in diabetic animals. The activity of Na+-K+-ATPase expressed per gram heart weight, but not per milligram sarcolemmal protein, was increased by etomoxir in diabetic animals. Furthermore, Bmax (per g heart wt) for both low-affinity and high-affinity binding sites in control and diabetic animals was increased by etomoxir treatment. Etomoxir treatment also increased the depressed left ventricular weight of diabetic rats and appeared to increase the density of the sarcolemma and transverse tubular system to normalize Na+-K+-ATPase activity. Therefore, a shift in myocardial substrate utilization may represent an important signal for improving the depressed cardiac function and Na+-K+-ATPase activity in diabetic rat hearts with impaired glucose utilization.

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