Renal nerve activity and exaggerated natriuresis in conscious spontaneously hypertensive rats
- 1 June 1981
- journal article
- research article
- Published by Wiley in Acta Physiologica Scandinavica
- Vol. 112 (2), 161-167
- https://doi.org/10.1111/j.1748-1716.1981.tb06800.x
Abstract
Exaggerated natriuresis upon volume loading occurs in both human and animal hypertension and is mainly due to suppressed tubular reabsorption. To explore whether altered renal sympathetic activity contributes to this response, conscious male spontaneously hypertensive rats (SHR) were exposed to isotonic saline loading in comparison with normotensive male Wistar Kyoto rats (WKR). After a 60 min control hydropenic period, during which mean arterial pressure, heart rate, renal sympathetic nerve activity and urinary sodium excretion were followed, a 60 min period of intravenous volume expansion with isotonic saline (0.2 ml/minx 100 g b. w.) was started followed by a 60 min hydropenic recovery period. Already during the control period sodium excretion was significantly higher in SHR. During the volume load and subsequent recovery period a clearly exaggerated natriuresis occurred in SHR compared with WKR. Further, volume loading reduced renal sympathetic nerve activity in all animals, but significantly more in SHR. Moreover, volume loading reduced mean arterial pressure and heart rate in both groups. It is suggested that the accentuated reflex inhibition of renal sympathetic activity in SHR upon volume loading emanates from cardiac mechanoreceptors and partly explains the exaggerated natriuresis in SHR. This augmented ‘volume’ reflex response is probably due to reduced systemic venous compliance in SHR with a consequently increased central filling and cardiac receptor activation.Keywords
This publication has 27 references indexed in Scilit:
- Renal Nerves and Sodium ExcretionAnnual Review of Physiology, 1979
- Chronic vascular constrictions and measurements of renal function in conscious ratsKidney International, 1979
- Renal function of conscious spontaneously hypertensive rats.Circulation Research, 1978
- Total effective compliance, cardiac output and fluid volumes in essential hypertension.Circulation, 1978
- Age-related changes in Na+ excretion in saline-loaded spontaneously hypertensive ratsAmerican Journal of Physiology-Legacy Content, 1976
- Abnormal relationship between sodium excretion and hypertension in spontaneously hypertensive ratsPflügers Archiv - European Journal of Physiology, 1975
- The effects of stimulation of the left atrial receptors on sympathetic efferent nerve activityThe Journal of Physiology, 1972
- Mechanism of exaggerated natriuresis in hypertensive man: impaired sodium transport in the loop of henleJournal of Clinical Investigation, 1969
- Exaggerated natriuresis in essential hypertensionThe American Journal of Medicine, 1958
- Effect of an Intravenous Sodium Chloride Load on Renal Hemodynamics and Electrolyte Excretion in Essential HypertensionCirculation, 1958