Regulation of glomerular volume in normal and partially
nephrectomized rats.
Cortes, Pedro, Xiyuan Zhao, Bruce L. Riser, and Robert G. Narins.
Department of Internal Medicine, Division of Nephrology and
Hypertension, Henry Ford Hospital, Detroit, Michigan 48202, USA
APStracts 2:0151F, 1995.
Glomerular extracellular matrix accumulation may derive from the
stretching of mesangial cells caused by excessive glomerular
dilatation.[circumflex]uThe relationship of glomerular volume (VG) to
intraglomerular pressure, expressed as compliance or as mean VG in
the isolated, perfused rat glomerulus, was used to analyze factors
that regulate VG.[circumflex]uGlomeruli were highly distensible over
the normal and relevant abnormal range of
pressure.[circumflex]uCompliance increased directly with basal VG (P
< 0.001), i. e., larger glomeruli dilated more than smaller ones
at any given pressure.[circumflex]uPerfusion with atrial natriuretic
peptide did not alter compliance and inhibitors of nitric oxide
synthesis exerted only a trivial effect.[circumflex]uVG expansion was
consistently reduced by angiotensin II but this effect was small
(3.8%, P < 0.001).[circumflex]uAfter subtotal nephrectomy,
compliance increased by 59% in the remnant glomeruli (P <
0.001);[circumflex]u22% of this increase was attributable to
structural changes and the remainder to the large basal VG of the
hypertrophied glomeruli.[circumflex]uThus, the major determinants of
VG expansion include:[circumflex]ucapillary wall tension, basal VG,
and intrinsic distensibility which is markedly influenced by the
character of the extracellular matrix and only slightly altered by a
AII-modified mesangial cell tone.
Received 5 June 1995; accepted in final form 21 August 1995.
APS Manuscript Number F180-5.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 15 September 1995.