Differential metal content and gene expression in rat left ventricular hypertrophy due to hypertension and hyperactivity.

The spontaneously hypertensive rat (SHR) has been studied extensively as a model of left ventricular hypertrophy (LVH) and associated cardiac dysfunction due to hypertension (HT). The SHR also possesses a hyperactive trait (HA). Crossbreeding SHR with Wistar-Kyoto (WKY) control rats, which are nonHT and nonHA, followed by selected inbreeding produced two additional homozygous strains: WKHT and WKHA, in which the traits of HT and HA, respectively, are expressed separately.

Cardiomyocyte function associated with hyperactivity and/or hypertension in genetic models of LV hypertrophy.

We examined cardiomyocyte intracellular calcium ([Ca2+]i) dynamics and sarcomere shortening dynamics in genetic rat models of left ventricular (LV) hypertrophy associated with or without hypertension (HT) and with or without hyperactive (HA) behavior. Previous selective breeding of the spontaneously hypertensive rat (SHR) strain, which is HA and HT, with the Wistar-Kyoto (WKY) rat strain, which is not hyperactive (NA) and not hypertensive (NT), has led to two unique strains: the WKHA strain, selected for HA and NT, and the WKHT strain, selected for NA and HT. Cardiomyocytes were isolated from young adult males and females of each strain, paced at 2, 3, and 4 Hz in 1.

No involvement of the nerve growth factor gene locus in hypertension in spontaneously hypertensive rats.

Sympathetic hyper-innervation and increased levels of nerve growth factor (NGF), an essential neurotrophic factor for sympathetic neurons, have been observed in the vascular tissues of spontaneously hypertensive rats (SHRs). Such observations have suggested that the pathogenesis of hypertension might involve a qualitative or quantitative abnormality in the NGF protein, resulting from a significant mutation in the gene's promoter or coding region. In the present study, we analyzed the nucleotide sequences of the cis-element of the NGF gene in SHRs, stroke-prone SHRs (SHRSPs), and normotensive Wistar-Kyoto (WKY) rats.

Elevated renal cortical calmodulin-dependent protein kinase activity and blood pressure.

The spontaneously hypertensive rat (SHR) exhibits not only hypertension but also behavioral hyperactivity which are not genetically linked. Two strains of rats, one hypertensive but normoactive (WKHT) and another, hyperactive but normotensive (WKHA), have been generated from SHR. We have reported that in renal proximal tubules, the linkage between D1-like receptors an adenylyl cyclase was impaired in SHR and WKHT but intact in WKHA.

WKHA rats with genetic hyperactivity and hyperreactivity to stress: a review.

WKHA rats are a homozygous strain of hyperactive rats developed by successive selected inbreedings, starting from a cross of spontaneously hypertensive (SHR) rats with their normotensive control strain, WKY. WKHA express hyperactivity in a novel environment, as do SHRs, however their blood pressure is normotensive, thus they are potentially a more promising model of hyperactivity than the SHR. WKHA became homozygous in 1990 (20 strict brother/sister inbreedings), and they are currently in the F36 generation.