Exaggerated muscle mechanoreflex control of reflex renal vasoconstriction in heart failure.

In heart failure (HF) patients, reflex renal vasoconstriction during exercise is exaggerated. We hypothesized that muscle mechanoreceptor control of renal vasoconstriction is exaggerated in HF. Nineteen HF patients and nineteen controls were enrolled in two exercise protocols: 1) low-level rhythmic handgrip (mechanoreceptors and central command) and 2) involuntary biceps contractions (mechanoreceptors). Renal cortical blood flow was measured by positron emission tomography, and renal cortical vascular resistance (RCVR) was calculated. During rhythmic handgrip, peak RCVR was greater in HF patients compared with controls (37 +/- 1 vs. 27 +/- 1 units; P < 0.01). Change in (Delta) RCVR tended to be greater as well but did not reach statistical significance (10 +/- 1 vs. 7 +/- 0.9 units; P = 0.13). RCVR was returned to baseline at 2-3 min postexercise in controls but remained significantly elevated in HF patients. During involuntary muscle contractions, peak RCVR was greater in HF patients compared with controls (36 +/- 0.7 vs. 24 +/- 0.5 units; P < 0.0001). The Delta RCVR was also significantly greater in HF patients compared with controls (6 +/- 1 vs. 4 +/- 0.6 units; P = 0.05). The data suggest that reflex renal vasoconstriction is exaggerated in both magnitude and duration during dynamic exercise in HF patients. Given that the exaggerated response was elicited in both the presence and absence of central command, it is clear that intact muscle mechanoreceptor sensitivity contributes to this augmented reflex renal vasoconstriction.

[1]  C. Hoh,et al.  Exaggerated renal vasoconstriction during exercise in heart failure patients. , 2000, Circulation.

[2]  A. Kunselman,et al.  Characteristics of the muscle mechanoreflex during quadriceps contractions in humans. , 1999, Journal of applied physiology.

[3]  L. Sinoway,et al.  Altered mechanisms of sympathetic activation during rhythmic forearm exercise in heart failure. , 1998, Journal of applied physiology.

[4]  C K Hoh,et al.  Modulation of renal cortical blood flow during static exercise in humans. , 1997, Circulation research.

[5]  R. Zelis,et al.  Forearm training attenuates sympathetic responses to prolonged rhythmic forearm exercise. , 1996, Journal of applied physiology.

[6]  B. Batman,et al.  Sympathetic nerve activity during prolonged rhythmic forearm exercise. , 1994, Journal of applied physiology.

[7]  J. Hill,et al.  Dynamic exercise stimulates group III muscle afferents. , 1994, Journal of neurophysiology.

[8]  M E Phelps,et al.  Quantification and parametric imaging of renal cortical blood flow in vivo based on Patlak graphical analysis. , 1993, Kidney international.

[9]  L. Sinoway,et al.  Effects of contraction and lactic acid on the discharge of group III muscle afferents in cats. , 1993, Journal of neurophysiology.

[10]  E. Hoffman,et al.  Use of the abdominal aorta for arterial input function determination in hepatic and renal PET studies. , 1992, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[11]  T. Mosher,et al.  Skeletal Muscle Metaboreceptor Exercise Responses Are Attenuated in Heart Failure , 1991, Circulation.

[12]  J. Longhurst,et al.  Sensitization of group III muscle afferents to static contraction by arachidonic acid. , 1990, Journal of applied physiology.

[13]  K. Murphy,et al.  The early circulatory and ventilatory response to voluntary and electrically induced exercise in man. , 1987, The Journal of physiology.

[14]  J. Kiley,et al.  Stimulation by central command of locomotion, respiration and circulation during exercise. , 1985, Respiration physiology.

[15]  J. Mitchell,et al.  Effects of static and rhythmic twitch contractions on the discharge of group III and IV muscle afferents. , 1984, Cardiovascular research.

[16]  T. Waldrop,et al.  Effect of ischemia on responses of group III and IV afferents to contraction. , 1984, Journal of applied physiology: respiratory, environmental and exercise physiology.

[17]  D. McCloskey Centrally-generated commands and cardiovascular control in man. , 1981, Clinical and experimental hypertension.

[18]  G. Borg Perceived exertion as an indicator of somatic stress. , 2019, Scandinavian journal of rehabilitation medicine.

[19]  C. Honig,et al.  Influence of initial resistance on magnitude of response to vasomotor stimuli. , 1969, The American journal of physiology.