Intrarenal Blood Flow Distribution in the Genetically Hypertensive Rat

Butt, T. J.; Jones, Davy; Bolli, Peter; Wallis, A.; Simpson, F. O.

doi:10.1159/000181949

Cited by 3 publications

(2 citation statements)

References 16 publications

(21 reference statements)

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“…Renal blood flow was 30% lower in both young and adult GH rats compared with N rats. This confirms previous observations in adult GH rats 34 and supports the trend reported by Baer et al 35 . in 4‐week‐old GH rats.…”

Section: Discussionsupporting

confidence: 93%

Effect of cross‐fostering on blood pressure and renal function in the New Zealand genetically hypertensive rat

Ashton

Kelly

Ledingham

2003

Clin Exp Pharma Physio

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1. The severity of hypertension displayed by adult spontaneously hypertensive rats (SHR) and Dahl (SS/Jr) rats can be reduced by 20-30 mmHg if the hypertensive pup is cross-fostered to a normotensive mother within the first 2 weeks of birth. In the SHR, at least, this blood pressure-lowering effect arises through programming of the neonatal kidney to excrete sodium more effectively. Thus, cross-fostering may only be effective in lowering pressure in salt-sensitive hypertensive strains. Accordingly, the aim of the present study was to determine whether cross-fostering is effective in lowering adult blood pressure in the salt-resistant New Zealand genetically hypertensive (GH) rat. 2. Genetically hypertensive and control normotensive (N) rat pups were reared by either their natural mothers or a foster mother of the opposite strain (NX and GHX). Blood pressure was tracked from the age of 6-18 weeks, at which time renal function was assessed using standard clearance techniques in anaesthetized rats. Renal function was also assessed in a separate group of young rats at 5-6 weeks of age. 3. Cross-fostered GHX rats had lower blood pressure than GH rats, but this difference was only apparent until 9 weeks. The NX rats had higher blood pressures than N rats, but again pressure converged at 10 weeks. Basal renal function did not differ between GH and GHX rats or between N and NX rats at either age. However, young GH rats had lower renal blood flow, glomerular filtration rate, urine output and sodium excretion than N rats. 4. These data show that cross-fostering is effective in lowering blood pressure in GH rats, albeit transiently. The kidneys do not appear to play a role, because renal function did not differ under the current experimental conditions between GH and GHX rats. However, the kidney may play a greater role in the onset of hypertension in the GH rat than previously thought.

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Section: Discussionsupporting

confidence: 93%

Effect of cross‐fostering on blood pressure and renal function in the New Zealand genetically hypertensive rat

Ashton

Kelly

Ledingham

2003

Clin Exp Pharma Physio

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“…21 In addition, a recent study showed reduced renal blood flow per unit mass of kidney tissue in the New Zealand SHR and a reduced distribution and flow to the outer cortical compartment. 29 The 6-week-old SHR has a lower renal blood flow and greater preglomerular pressure drop. 30 -3I These findings suggest a preglomerular vascular origin, which emphasize the possible role of the kidney in the pathogenesis of hypertension in the SHR.…”

Section: Afferent Arteriolar Findingsmentioning

confidence: 99%

Renal afferent arteriole in the spontaneously hypertensive rat.

Gattone¹,

Evan²,

Willis³

et al. 1983

Hypertension

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SUMMARY We conducted morphometric studies on the afferent arteriole of spontaneous hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats to gain a better understanding of its changes with the development of hypertension. Differences may be related to the SHRs' increased renal vascular resistance. Methacrylate vascular casts were made of the renal vasculature after perfusion fixation with glutaraldehyde. These vascular casts were then examined and measurements made with the scanning electron microscope. Results from this examination of the scanning electron microscope demonstrated a smaller afferent arteriolar diameter in the SHR, compared to the WKY, for both the inner and outer cortical glomeruli. This difference was seen in the 6-week-old SHR, prior to a statistically different blood pressure from the WKY controls, as well as in the 12-week-old hypertensive SHR. However, this afferent diameter difference between rat strains was more pronounced in rats at 12 weeks of age. The tapering of the afferent arteriole (difference between proximal and distal afferent diameters) was greater in the 12-week-old SHR than in the age-matched WKY or 6-week-old SHR. We conclude that the smaller caliber afferent arterioles of the SHR may predispose and play a role in the pathogenesis of the subsequent hypertension. The increased afferent arteriolar tapering seen in the hypertensive SHR relates to the already present increased blood pressure. Wall thickness/ radius ratios are not different between rat strains (SHR and WKY) at either 6 or 12 weeks of age. These results suggest increased vascular constriction or hypoplastic vessels as the cause of the smaller caliber vessels in the SHR rather than increased wall thickness. These data have led to an interest in the morphology and physiology of the vascular system during hypertension. 2 3 The mesenteric vessels of the SHR show a decreased vascular compliance 4 and increased norepinephrine sensitivity 3 as compared to the WKY even prior to the development of hypertension. Similarly, changes have been described in the glomerular filtration barrier of the prehypertensive spontaneously hypertensive rats (SHR).3 Changes in the intrarenal vas- cular system could be especially significant since the kidneys have been shown to play an essential role in the development of hypertension in this rat model. 6The major resistance vessels of the kidney are the afferent arterioles. At present there is limited information concerning these vessels in the prehypertensive and hypertensive SHR. Therefore, the present study is designed to determine if there are changes occurring in the morphology of the afferent arteriole of the SHR with the onset of hypertension. The resistant blood vessels were examined through the use of methacrylate vascular casts, which allowed a morphometric analysis of the entire length of the afferent arteriole.Our data show that the afferent arterioles of the SHR have a smaller diameter, even prior to the onset of blood pressure difference compared to the Wistar Kyoto (WKY) control...

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Role of the Kidney in the Pathogenesis of Primary Hypertension

Bianchi¹

1982

Hypertensive Cardiovascular Disease: Pathophysiology and Treatment

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Intrarenal Blood Flow Distribution in the Genetically Hypertensive Rat

Cited by 3 publications

References 16 publications

Effect of cross‐fostering on blood pressure and renal function in the New Zealand genetically hypertensive rat

Effect of cross‐fostering on blood pressure and renal function in the New Zealand genetically hypertensive rat

Renal afferent arteriole in the spontaneously hypertensive rat.

Role of the Kidney in the Pathogenesis of Primary Hypertension

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