Morphological changes in juxtaglomerular cells by long-term treatment with an angiotensin-converting enzyme inhibitor in beige rats(chediak-higashi syndrome).

Abstract

To determine the effect of long-term treatment with an angiotensin-converting enzyme (ACE) inhibitor on the morphological change in juxtaglomerular (JG) cells, and the influence of plasma angiotensin II (PAG II) in renin synthesis and secretion in beige rats, an animal model of Chediak-Higashi syndrome, show gradually enlarged and irregularly-shaped JG granules (renin in the granules) according to their degree of maturity. Beige rats were administrated trandolapril, an ACE inhibitor, orally for 4 weeks. Morphological changes in JG cells and renin-angiotensin system function were determined. These rats were examined histologically and ultrastructurally, focussing on morphological changes in JG cells along witg blood pressure, PAG II, and plasma renin activity. Trandolapril reduced systolic blood pressure and decreased PRA remark-ably, but PAG II was highly variable. The most conspicuous histological changes were hypertrophy and hyperplasia of JG cells. Ultrastructurally, JG cells contained an increased number of JG granules of varying morphology. Most JG granules decreased in size and contained smooth materials, but some showed a granular matrix. These results demonstrate that chronic ACE inhibition accelerates synthesis of JG granules including renin and inhibits secretion of renin, but it is not confirmed whether renin synthesis and secretion are affected by PAG II.