Glomerular targeting of acidic fibroblast growth factor-1 in renal transplanted rats.
BACKGROUND
Acidic fibroblast growth factor (FGF-1) functions as a potent hormonal inducer of wound repair mechanisms in vivo. In addition, the involvement of FGF-1 in a number of pathophysiological conditions, including chronic human renal allograft rejection, has been described. Consequently, there is an increasing need to monitor FGF-1 pharmacokinetics and distribution for both therapeutic and diagnostic opportunities. We now describe in vivo imaging and targeting of FGF-1 in renal transplanted rats.


METHODS
Sham-operated, syngeneic renal transplanted, and allogeneic renal transplanted rats were imaged using an Anger gamma camera. Renal function was evaluated first by dynamic 99mTc-MAG3 imaging, and subsequently, 99mTc-labeled FGF-1 (99mTc-FGF-1) was imaged after i.v. injection. Microautoradiography of harvested kidneys determined the compartmental localization of 99mTc-FGF-1.


RESULTS
99mTc-MAG3 renal scans were grossly abnormal in the allogeneic renal transplanted rats. In this group, a significant reduction in 99mTc-FGF-1 renal binding was measured by imaging analyses, as compared with renal binding in the sham-operated and syngeneic renal transplanted groups, which were not significantly different. Both groups of renal transplanted rats showed a redistribution of FGF-1 to the glomerular compartment.


CONCLUSIONS
99mTc-FGF-1 serves as a new radiotracer to measure in vivo targeting of the growth factor. Reduced renal binding of 99mTc-FGF-1 in the allogeneic transplanted kidney was consistent with decreased blood flow. Unique glomerular targeting of 99mTc-FGF-1 in the transplanted kidney provides additional evidence supporting a role for this growth factor in the pathogenesis of chronic rejection.
Zinn
Kurt R
KR
Department of Radiology, University of Alabama at Birmingham, Birmingham, AL 35294-0012, USA.
Kelpke
Stacey
S
Akhi
Kabir
K
Viera
Liliana
L
Chaudhuri
Tandra R
TR
Thompson
John A
JA
D000419:Albuminuria / Q000652:urine; D000818:Animals; D001345:Autoradiography; D016220:Fibroblast Growth Factor 1 / Q000493:pharmacokinetics*; D007668:Kidney / Q000473:pathology / Q000503:physiopathology; D007677:Kidney Function Tests; D007678:Kidney Glomerulus / Q000378:metabolism*; D016030:Kidney Transplantation; D008297:Male; D019275:Radiopharmaceuticals; D051381:Rats; D011916:Rats, Inbred F344; D011917:Rats, Inbred Lew; D013667:Technetium; D017263:Technetium Tc 99m Mertiatide; D014018:Tissue Distribution; D014184:Transplantation, Homologous; D014185:Transplantation, Isogeneic
D019275:Radiopharmaceuticals; D016220:Fibroblast Growth Factor 1; D017263:Technetium Tc 99m Mertiatide; D013667:Technetium