Metanephros transplantation inhibits the progression of vascular calcification in rats with adenine-induced renal failure.
OBJECTIVE
Recent research has shown that transplanted metanephroi form primitive vascularized kidneys with histologically recognizable renal features. The aim of the present study was to determine the metabolic function of transplanted metanephroi in rats with chronic renal failure (CRF), with particular reference to secondary hyperparathyroidism and vascular calcification.


METHODS
CRF was induced in 11-week-old male Wistar rats by maintaining them on a 0.75% adenine diet for 4 weeks, followed by normal diet for an additional 2 weeks. At the end of adenine loading, whole metanephroi from embryonic day 15 rats were transplanted into the omentum and epididymis of the transplantation group. Vascular calcification was evaluated 2 weeks after metanephroi transplantation.


RESULTS
Metanephros transplantation significantly reduced vascular calcium and phosphorus content and suppressed the progression of vascular calcification as indicated by von Kossa staining of the media of the thoracic aorta. However, no significant differences between the adenine-fed control and transplantation groups were found regarding the serum levels of 1,25(OH)2D3, calcium or phosphorus or the calcium × phosphorus product.


CONCLUSIONS
The present study has shown that transplantation of metanephroi suppresses the progression of vascular calcification via a mechanism that is independent of calcium-phosphorus dynamics.
Division of Nephrology and Hypertension, Department of Internal Medicine, The Jikei University School of Medicine, Tokyo, Japan.
Shinya
S
Yokote
Takashi
T
Yokoo
Kei
K
Matsumoto
Ichiro
I
Ohkido
Yasunori
Y
Utsunomiya
Tetsuya
T
Kawamura
Tatsuo
T
Hosoya
D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase / Q000235:genetics; D000225:Adenine / Q000008:administration & dosage; D000818:Animals; D001013:Aorta, Thoracic / Q000473:pathology; D002117:Calcitriol / Q000097:blood; D002118:Calcium / Q000097:blood; D003404:Creatinine / Q000097:blood; D016332:Fetal Tissue Transplantation / Q000379:methods*; D015870:Gene Expression; D007668:Kidney / Q000098:blood supply / Q000196:embryology / Q000378:metabolism; D007676:Kidney Failure, Chronic / Q000097:blood / Q000209:etiology / Q000601:surgery*; D016030:Kidney Transplantation / Q000379:methods*; D026561:Low Density Lipoprotein Receptor-Related Protein-2 / Q000235:genetics; D008297:Male; D010758:Phosphorus / Q000097:blood; D051381:Rats; D017208:Rats, Wistar; D011956:Receptors, Cell Surface / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014057:Tomography, X-Ray Computed; D061205:Vascular Calcification / Q000097:blood / Q000628:therapy*
D026561:Low Density Lipoprotein Receptor-Related Protein-2; D011956:Receptors, Cell Surface; C029486:intrinsic factor-cobalamin receptor; D010758:Phosphorus; D003404:Creatinine; D015090:25-Hydroxyvitamin D3 1-alpha-Hydroxylase; D002117:Calcitriol; D000225:Adenine; D002118:Calcium