Abstract
Objective: To verify whether the normal kidney exerts a supportive, facilitatory action on renal sympathetic nerve activity (RSNA), the effects of unilateral and bilateral nephrectomy on RSNA have been studied. Methods: The RSNA, rectal temperature (T), rate of breathing (RB), arterial blood pressure (BP) and heart rate (HR) were continuously recorded in three groups of pentobarbital anaesthetized, spontaneously breathing Sprague-Dawley rats: group 1 (n = 5): both kidneys intact; group 2 (n = 5): left surgical nephrectomy; group 3 (n = 5): left surgical nephrectomy and functional exclusion of the right kidney (functional right nephrectomy, FRN), produced by a tight ligature of the renal hilum which was maintained for 3 h. In a fourth group (n = 7), in which nerve activity was not recorded, reopening of the right renal hilum was preceded or followed by intravenous administration of captopril (3 mg/kg). Results: In groups 1 and 2 RSNA increased from 22.3 ± 2.1 to 122.9 ± 13.6 and from 26.7 ± 1.2 to 93.2 ± 14.0 impulses/s (mean ± SEM), respectively, without concomitant changes in cardiovascular parameters. In group 3 RSNA decreased from 39.1 ± 3.1 to 13.7 ± 2.6 impulses/s during the 3 h of FRN. In group 3 the reopening of the right renal hilum was followed by a marked increase in BP and HR that was prevented or reversed by intravenous captopril in rats of group 4. Conclusions: The decrease in RSNA observed in rats during bilateral nephrectomy, in contrast to the increase observed in rats with one or both kidneys intact, suggests that the kidney as a whole exerts a supportive role on sympathetic nerve activity. The hypertension and tachycardia that follows the reopening of the right kidney hilum appears to be caused by the generation of endogenous angiotensin II; this is the first evidence of an acute angiotensin-mediated renal hypertension. (C) Lippincott Williams and Wilkins.
Original language | English |
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Pages (from-to) | 1277-1287 |
Number of pages | 11 |
Journal | Journal of Hypertension |
Volume | 18 |
Issue number | 9 |
Publication status | Published - 2000 |
Keywords
- Acute angiotensin-mediated hypertension
- Acute renal hypertension
- Angiotensin converting enzyme inhibitors
- Experimental hypertension
- Functional nephrectomy
- Nephrectomy
- Renal chemoreceptors
- Renal nerve activity
- Renal sensory innervation
- Sympathetic nerve activity
ASJC Scopus subject areas
- Internal Medicine
- Endocrinology