Skip to main content

Diversity of responses of renal cortical and medullary blood flow to vasoconstrictors in conscious rabbits

Buy Article:

$43.00 plus tax (Refund Policy)

The medullary microcirculation receives only about 10% of total renal blood flow, but plays a critical role in long-term arterial pressure regulation, so we need to better understand its regulation. Although there is evidence that circulating and locally acting hormones can differentially affect cortical and medullary blood flow in anaesthetized animals, there is little information from studies in conscious animals. This study is aimed (i) to develop a method for chronic measurement of cortical and medullary blood flow in conscious rabbits, and (ii) to test whether renal cortical and medullary blood flow can be differentially affected by intravenous (i.v.) infusions of various vasoconstrictor hormones in conscious rabbits. At preliminary operations, rabbits were equipped with single-fibre laser-Doppler flowprobes in the (left) renal cortex and medulla, and Transonic flowprobes for measuring cardiac output and renal blood flow. Intravenous angiotensin II (300 ng kg–1 min–1), [Phe2,Ile3,Orn8]-vasopressin (30 ng kg–1 min–1), noradrenaline (300 ng kg–1 min–1), endothelin-1 (20 ng kg–1 min–1) and N G-nitro-L-arginine (10 mg kg–1) increased mean arterial pressure (by 10–45% of baseline) and reduced heart rate (by 16–35%) and cardiac output (by 16–45%). Consistent with previous observations in anaesthetized rabbits, all treatments except [Phe2,Ile3,Orn8]-vasopressin reduced renal blood flow (13–63%) and cortical blood flow (16–47%), but medullary blood flow was significantly reduced only by [Phe2,Ile3,Orn8]-vasopressin (41%) and N G-nitro-L-arginine (42%). The diversity of these responses of cortical and medullary blood flow to i.v. infusions of vasoconstrictors provides further evidence for physiological roles of circulating and local hormones in the differential regulation of regional kidney blood flow.
No References
No Citations
No Supplementary Data
No Data/Media
No Metrics

Keywords: angiotensin II; conscious rabbit; endothelin; nitric oxide; noradrenaline; renal cortical blood flow; renal medullary blood flow; vasopressin

Document Type: Research Article

Affiliations: Department of Physiology, Monash University, Victoria, Australia

Publication date: 2000-08-01

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more