Structural changes in the renal vasculature in streptozotocin-induced diabetic rats without hypertension.
OBJECTIVE
We evaluated in diabetic-streptozotocin rats (STZR) the structural changes of glomeruli, preglomerular vessels, glomerular tuft and renal parenchyma in order to determine the degree of renal injury and the presence of remodeling in afferent arterioles developed by diabetes without overimposed hypertension.


METHODS
Renal mass index and histological score (glomerular number, density, tubular lesions and degree of arteriosclerosis) were estimated. In afferent arterioles the ratio of wall thickness/lumen was obtained by stereological methods.


RESULTS
STZR developed diabetes without hypertension; renal mass index increased and matched changes in glomeruli (decrease of capillary number and enlargement of mesangium and basement capillary membrane). Both glomerular number and density as well as afferent arteriole number were diminished. Degenerative changes in both proximal (glycogenic and hyaline degeneration) and distal tubules (hyaline casts) were also observed. At variance with preglomerular vessels, the efferent arterioles only presented initial arteriosclerosis. Finally, the stereological study of afferent arterioles showed a significantly lower arteriolar lumen area and arteriolar wall thickness in STZR, resulting in a remodeling without modification of wall/lumen ratio.


CONCLUSIONS
Diabetes, uncomplicated by hypertension, is associated with (1) a reduction in glomerular number; (2) degeneration in parenchyma and renal tubules, and (3) a specific pattern of remodeling in preglomerular vessels different from that induced by hypertension. Although this work demonstrated that these changes are not triggered by hypertension, further investigations are required in order to determine which mediators are involved in diabetic-vascular renal dysfunction.
Turoni
Claudio M Joo
CM
Department of Physiology, INSIBIO, Universidad Nacional de Tucumán, Tucumán, Argentina.
Reynoso
Héctor A
HA
Marañón
Rodrigo O
RO
Coviello
Alfredo
A
Peral de Bruno
María
M
D000818:Animals; D050197:Atherosclerosis / Q000209:etiology / Q000473:pathology*; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000150:complications / Q000473:pathology*; D003928:Diabetic Nephropathies / Q000473:pathology*; D006973:Hypertension / Q000473:pathology; D007668:Kidney / Q000098:blood supply* / Q000187:drug effects / Q000473:pathology*; D008297:Male; D008833:Microcirculation / Q000187:drug effects / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013311:Streptozocin
D013311:Streptozocin