Sexual hormones modulate compensatory renal growth and function

PABLO J AZURMENDI; ELISABET M ODDO; JORGE E TOLEDO; RODOLFO S MARTÍN; FERNANDO R IBARRA; ELVIRA E ARRIZURIETA

NEPHROLOGY DIALYSIS TRANSPLANTATION

OXFORD UNIV PRESS

Lugar: Oxford; Año: 2012

0931-0509

Factors involved in compensatory renal growth (CRG) after uninephrectomy (uNx) are still not well understood. Sexual hormones and vasoactive substances have been studied and their role in this subject is controversial.  To elucidate some standing questions, intact and gonadectomized (Gx) adult Wistar rats of either sex, with and without uNx were studied at 150 days old. In a 24 hour urine, water, electrolyte and kallikrein activity (UKa) were determined.. Afterwards, glomerular filtration rate (GFR) was measured and the kidneys were weighed and, protein, RNA and DNA were studied. When the remnant kidney weight was compared with the weight of the kidney removed at uNx, male uNx rats showed the greatest CRG (50%) while growth in the other groups was negligibly, particularly in female groups. GFR accompanied morphological findings showing also the uNx female rats the lowest value, 0.56±0.02 ml/min/g kwt , with respect to the other uNx groups (0.97±0.09 , p<0.05). Cells size was similar for all the groups except for male Gx uNx rats. In this group the cytoplasmatic protein or RNA content was lower than in the other groups but DNA was similar. Some degree of hyperplasia was estimated in the uNx groups by DNA. UKa showed a sex dimorphism in intact and uninephrectomized animals that is disrupted after gonads removal in male rats. Male sexual hormones positively influenced CRG and,  its absence, modulates UKa and cell size. Besides CRG appears to result from a combined mechanism involving hypertrophy and hyperplasia.