Plasminogen activator inhibitor-1 and tissue-type plasminogen activator are up-regulated during unilateral ureteral obstruction in adult rats.
OBJECTIVE
The plasminogen activator (PA)-plasmin system has been shown to influence turnover of the extracellular matrix in various tissues. We examined the alteration of plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (t-PA) in kidneys with unilateral ureteral obstruction in rats.


METHODS
Female rats that underwent ligation of the left ureter were sacrificed 12 hours, 1, 5 or 10 days later. The expressions of PAI-1 and t-PA was determined by reverse transcription-polymerase chain reaction and immunohistochemical studies in the obstructed and contralateral kidneys in each group.


RESULTS
Control kidneys showed no PAI-1 messenger (m)RNA expression. After days 1 through 10 of unilateral ureteral obstruction the amount of PAI-1 mRNA significantly increased in obstructed compared with contralateral kidneys (p <0.01). Meanwhile, slight polymerase chain reaction products of t-PA were observed in control kidneys. After 12 hours through 10 days of unilateral ureteral obstruction, t-PA mRNA in obstructed and contralateral kidneys was significantly elevated compared with in control kidneys (p <0.05). No significant difference in t-PA was observed in the obstructed and contralateral kidneys in each group. Immunoreactivity to PAI-1 and t-PA was identified in obstructed kidneys.


CONCLUSIONS
PAI-1 and t-PA are up-regulated in obstructed rat kidneys. Our results indicate that the PA-plasmin system has a role in the process of matrix accumulation and degradation during rat obstructive nephropathy.
Ishidoya
Shigeto
S
Department of Urology, Tohoku University Graduate School of Medicine, Sendai, Japan.
Ogata
Yukihiko
Y
Fukuzaki
Atsushi
A
Kaneto
Hiroyuki
H
Takeda
Atsushi
A
Orikasa
Seiichi
S
D000818:Animals; D004195:Disease Models, Animal; D005109:Extracellular Matrix; D005260:Female; D007150:Immunohistochemistry; D017395:Plasminogen Activator Inhibitor 1; D016133:Polymerase Chain Reaction; D051381:Rats; D017207:Rats, Sprague-Dawley; D010959:Tissue Plasminogen Activator; D015854:Up-Regulation; D014517:Ureteral Obstruction / Q000097:blood / Q000503:physiopathology*
D017395:Plasminogen Activator Inhibitor 1; D010959:Tissue Plasminogen Activator