Structural and reactivity alterations of the renal vasculature of spontaneously XXXX @entity35 prior to and during established @entity101 .

@entity9976 @entity101 @entity1808 @entity12947 @entity35 @entity1063
The renal vasculature of @entity35 Kyoto spontaneously @entity101 @entity35 (SHR), prior to (4-5 week) and during established @entity101 (21 week) and those of age-matched @entity35 Kyoto normotensive @entity35 (WKY) were morphometrically and pharmacologically studied. Under dilated conditions, the vascular resistances (RVR) of the isolated kidneys of young and adult SHR were similar to WKY. Morphometric measurements of renal vasculature indicated that the cross-sectional area of the intima and adventitia and its subcomponents were similar in adult SHR and WKY. With the exception of the preglomerular arterioles, all the renal arteries of adult SHR exhibited elevated cross-sectional quantities of total media, medial smooth muscle cells (SMCs), and extracellular space. Analysis of the SMCs indicated the presence of increased numbers of @entity9976 and/or an increase in the SMC volume-to-surface area ratio in arteries sampled from adult SHR. Vascular contraction produced by infusing @entity1063 , @entity12947 , @entity1808 , or by stimulating the renal nerves elevated the RVR to a greater degree in adult SHR than in WKY. The sensitivity of the renal vasculature to the various contractile agents was similar in adult SHR and WKY. When compared with WKY, prehypertensive SHR also exhibited increased cross-sectional quantities of arterial media and elevated amplitudes of RVR change in response to @entity1063 and renal nerve stimulation. However, the vascular contractile sensitivity to @entity1063 was reduced. Our results indicate that renovascular wall thickening and the hypercontractile reactivity associated with such a change precedes @entity101 in SHR. In prehypertensive SHR, elevations in RVR might be counterbalanced by a decreased @entity1063 sensitivity. An increase in the @entity1063 contractile sensitivity and further vascular thickening with age could elevate the RVR and establish @entity101 .
