Influence of a high salt diet on glomerular injury and the preventive effects of amiloride in adriamycin nephropathy.
The effects of a high salt diet on glomerular hypertrophy and sclerosis were examined in a focal glomerular sclerosis rat model. Sprague-Dawley rats were injected twice with Adriamycin (ADR, 2.5 mg/kg body weight) and then divided into 3 groups: (1) ADR rats fed a 1% sodium chloride (NaCI) diet (control ADR rats); (2) ADR rats fed an 8% NaC1 diet (ADR-NaC1 group), and (3) ADR rats fed a 10% sodium bicarbonate (NaHCO3) diet (the ADR-NaHCO3 group), and were then observed for 8 weeks. There were no differences in the blood pressure levels between the control ADR and ADR-NaC1 groups. The urinary protein excretion was significantly less in the ADR-NaC1 and ADR-NaHCO3 groups than in the control ADR group. However, a progressive increase in the blood urea nitrogen and serum creatinine associated with extensive glomerular sclerosis and hypertrophy was only observed in the ADR-NaC1 group. An increase in the glomerular diameter preceded the development of glomerulosclerosis in this group. Furthermore, a daily administration of amiloride, a Na+/H+ exchanger inhibitor, to the ADR-NaC1 rats prevented the development of glomerular hypertrophy and sclerosis. These results therefore suggest that the aggravated effect of a high salt diet on glomerular sclerosis may be related to glomerular hypertrophy which is associated with the stimulation of the Na+/H+ exchanger.
Nagashima
A
A
Second Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Okuda
S
S
Tamaki
K
K
Fujishima
M
M
D000584:Amiloride / Q000627:therapeutic use*; D000818:Animals; D003404:Creatinine / Q000378:metabolism; D004195:Disease Models, Animal; D004232:Diuretics / Q000627:therapeutic use*; D005923:Glomerulosclerosis, Focal Segmental / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000378:metabolism; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage / Q000009:adverse effects*
D004232:Diuretics; D017673:Sodium Chloride, Dietary; D000584:Amiloride; D012964:Sodium; D003404:Creatinine