Glomerular cell replication and cell loss through apoptosis in experimental diabetes mellitus.
OBJECTIVE
To evaluate changes in the glomerular cell balance between replication and apoptosis in experimental diabetes mellitus (DM) in relation to morphometric data.


METHODS
Adult Sprague-Dowley rats with streptozotocin-induced DM and controls of the same age and strain were sacrificed 4 and 8 weeks and 6 months after disease onset. Cell replication was demonstrated with MIB-5, and apoptosis with the terminal uridine nick end labeling technique. Glomerular size and glomerular cell population were estimated morphologically.


RESULTS
Diabetic and control rats showed irrelevant MIB-5 positivity at all time points. Glomerular apoptosis was minimal in rats with 4 and 8 weeks of DM and in controls. Rats with 6 months of DM showed significantly higher glomerular apoptosis values than controls (2.49 +/- 0.25 vs. 0.65 +/- 0.16%; p < 0.001). The mean cell count per glomerular profile was significantly lower in these diabetic rats (64.02 +/- 1.93 vs. 78.27 +/- 0.99; p < 0.001), a change that correlated with that in apoptosis. The glomerular cell density was further decreased in diabetic rats because of the diabetic increase in mean glomerular volume (1.598 vs. 0.927 10(6) microm).


CONCLUSIONS
Apoptosis is associated with loss of glomerular cells in rats with long-term, streptozotocin-induced DM and - to a considerably lower degree - in controls of the same age and strain. These changes could be relevant to glomerulosclerosis associated with long-term, streptozotocin-induced DM.
Pesce
Carlo
C
Centro di Anatomia Patologica, DISTBIMO, Università di Genova, Italia. pesce@unige.it
Menini
Stefano
S
Pricci
Flavia
F
Favre
Anna
A
Leto
Gaetano
G
DiMario
Umberto
U
Pugliese
Giuseppe
G
D000818:Animals; D017209:Apoptosis; D002455:Cell Division; D003921:Diabetes Mellitus, Experimental / Q000473:pathology* / Q000503:physiopathology; D020287:In Situ Nick-End Labeling; D007678:Kidney Glomerulus / Q000473:pathology*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors