Neurohumoral interactions contributing to renal vasoconstriction and decreased renal blood flow in heart failure.

Neurohumoral interactions contributing to renal vasoconstriction and decreased renal blood flow in heart failure. Am J Physiol Regul Integr Comp Physiol. 2019 Jun 26;: Authors: Ramchandra R, Xing DT, Matear M, Lambert G, Allen AM, May CN Abstract In heart failure (HF), increases in renal sympathetic nerve activity (RSNA), renal norepinephrine spillover and renin release cause renal vasoconstriction, which may contribute to the cardiorenal syndrome. To increase our understanding of the mechanisms causing renal vasoconstriction in HF we investigated the interactions between the increased activity of the renal nerves and the renal release of norepinephrine and renin in an ovine pacing-induced model of HF. In addition, we determined the level of renal angiotensin type-1 receptors and the renal vascular responsiveness to stimulation of the renal nerves and α1-adrenoceptors. In conscious sheep with mild HF (ejection fraction 35-40%), renal blood flow (276±13 to 185±18 mL/min) and renal vascular conductance (3.8±0.2 to 3.1±0.2 mL/min/mmHg) decreased. There were increases in the burst frequency of renal sympathetic nerve activity (RSNA) (+27%), renal norepinephrine spillover (+377%) and plasma renin activity (+141%), while the density of renal medullary angiotensin type-1 receptors decreased. In anaesthetised sheep with HF, the renal vasoconstrictor responses to electrical stimulation of the renal nerves or to phenylephrine were attenua...
Source: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology - Category: Physiology Authors: Tags: Am J Physiol Regul Integr Comp Physiol Source Type: research