Quantitative analysis of the renal aging in rats. Stereological study.
OBJECTIVE
To evaluate the renal function and the renal histological alterations through the stereology and morphometrics in rats submitted to the natural process of aging.


METHODS
Seventy two Wistar rats, divided in six groups. Each group was sacrificed in a different age: 3, 6, 9, 12, 18 and 24 months. It was performed right nephrectomy, stereological and morphometric analysis of the renal tissue (renal volume and weight, density of volume (Vv[glom]) and numerical density (Nv[glom]) of the renal glomeruli and average glomerular volume (Vol[glom])) and also it was evaluated the renal function for the dosage of serum creatinine and urea.


RESULTS
There was significant decrease of the renal function in the oldest rats. The renal volume presented gradual increase during the development of the rats with the biggest values registered in the group of animals at 12 months of age and significant progressive decrease in older animals. Vv[glom] presented statistically significant gradual reduction between the groups and the Nv[glom] also decreased significantly.


CONCLUSIONS
The renal function proved to be inferior in senile rats when compared to the young rats. The morphometric and stereological analysis evidenced renal atrophy, gradual reduction of the volume density and numerical density of the renal glomeruli associated to the aging process.
Fellow Master degree, Postgraduate Program in Surgical Clinic, Department of Urology, Federal University of Parana (UFPR), Curitiba-PR, Brazil. Scientific, intellectual, conception and design of the study; acquisition, analysis and interpretation of data; technical procedures; histopathological examinations; statitics analysis; manuscript writing; critical revision., Universidade Federal do Paraná, Department of Urology, Federal University of Parana, Curitiba PR , Brazil.
Eduardo Felippe
EF
Melchioretto
MD, Volunteer, Department of Urology, UFPR, Curitiba-PR, Brazil. Scientific and intellectual content of the study, acquisition of data, technical procedures., Universidade Federal do Paraná, Department of Urology, UFPR, Curitiba PR , Brazil.
Marcelo
M
Zeni
PhD, Associate Professor, Department of Anatomy, School of Medicine, UFPR, Curitiba-PR, Brazil. Scientific, intellectual, conception and design of the study; analysis and interpretation of data; histopathological examinations; critical revision., Universidade Federal do Paraná, Department of Anatomy, School of Medicine, UFPR, Curitiba PR , Brazil.
Djanira Aparecida da Luz
DA
Veronez
Graduate student, School of Medicine, UFPR, Curitiba-PR, Brazil. Acquisition of data, technical procedures, histopathological examinations., Universidade Federal do Paraná, School of Medicine, UFPR, Curitiba PR , Brazil.
Eduardo Lopes
EL
Martins
PhD, Associate Professor, Department of Urology, School of Medicine, UFPR, Curitiba-PR, Brazil. Scientific, intellectual, conception and design of the study; analysis and interpretation of data; statistics analysis; critical revision., Universidade Federal do Paraná, Department of Urology, School of Medicine, UFPR, Curitiba PR , Brazil.
Rogério de
Rd
Fraga
D000375:Aging / Q000502:physiology*; D000818:Animals; D003404:Creatinine / Q000097:blood; D005069:Evaluation Studies as Topic; D007668:Kidney / Q000033:anatomy & histology* / Q000502:physiology*; D007678:Kidney Glomerulus / Q000503:physiopathology; D008297:Male; D009929:Organ Size / Q000502:physiology; D017208:Rats, Wistar; D014508:Urea / Q000097:blood
D014508:Urea; D003404:Creatinine