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The juxtaglomerular apparatus of the spontaneously hypertensive rat
Author(s) -
FARAJ A. H.,
MORLEY A. R.,
LINDOP G. B. M.
Publication year - 1991
Publication title -
apmis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0903-4641
DOI - 10.1111/j.1699-0463.1991.tb05130.x
Subject(s) - juxtaglomerular apparatus , chemistry , medicine , renin–angiotensin system , endocrinology , blood pressure
Spontaneously hypertensive rats (SHR) are used to study the pathogenesis of essential hypertension. This study investigates the role of the renin‐angiotensin system (RAS) in the pathogenesis of hypertension in SHRs and the morphometry of the JGA by a three‐dimensional computer reconstruction program “GLOM” and electron microscopy. Systolic blood pressure (SBP) (tail cuff method) was higher in SHRs compared to controls (P<0.001). Plasma renin concentration (PRC) was lower in SHRs than in controls (P<0.001). Reconstruction of the JGA revealed granulated JG cells in the afferent and efferent arterioles and in the vascular tree away from the JGA area. Electron microscopy showed granulated JG cells in the afferent and efferent arterioles. The percentage volume of the granulated JG cells in SHR was significantly higher than in controls (P<0.01). A relationship was found between the percentage volume of granulated JG cells and the SBP in SHRs (r = 0.933, P<0.05). The wall/lumen perimeter ratio was also significantly higher in the SHRs compared to the controls (P<0.05). Low PRC in SHRs has been reported by several workers. The apparent hyperactivity of the JGA may indicate failure of renin release or an abnormal synthesis/secretion rate.