title: TGF-initiated vascular interactions between adjacent nephrons in the rat kidney.
abstract: We sought to determine whether tubuloglomerular feedback (TGF), activated from one nephron, affects other arterioles derived from the same cortical radial artery. Surface nephrons supplied by a single cortical radial artery were identified by injecting Ringer solution containing Fast Green from a narrow-gauge polyethylene catheter inserted via a lumbar artery into a renal artery. Stop-flow pressure was measured in an identified nephron from such a grouping. In one series, increasing end-proximal flow rate from 0 to 50 nl/min of synthetic tubular fluid in one member of an identified pair of nephrons reduced stop-flow pressure by 1.3 +/- 0.2 mmHg in the other member. When the nephrons were derived from different cortical radial arteries, the stop-flow pressure changed -0.2 +/- 0.1 mmHg. In another series, increasing flow in the adjacent nephron from 0 to 50 nl/min decreased stop-flow pressure 3.9 +/- 0.9 mmHg, and increasing flow in the adjacent nephron by the same amount when flow in the first nephron was 50 nl/min decreased stop-flow pressure 3.4 +/- 0.7 mmHg. These results indicate the operation of an interaction among nephrons derived from a common cortical radial artery. Such an interaction could produce a cooperative effect larger than that predicted from measured single-nephron responses when systemic arterial pressure changes.
authors.affiliation: Department of Physiology, Uppsala University, Sweden.
authors.forename: O
authors.initials: O
authors.lastname: Källskog
authors.forename: D J
authors.initials: DJ
authors.lastname: Marsh
mesh_terms: D000818:Animals; D002406:Catheterization, Peripheral; D005246:Feedback / Q000502:physiology; D007678:Kidney Glomerulus / Q000502:physiology*; D007684:Kidney Tubules / Q000502:physiology*; D008297:Male; D009399:Nephrons / Q000098:blood supply / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012079:Renal Circulation / Q000502:physiology