The borderline hypertensive rat (BHR): A new model for the study of environmental factors in the development of hypertension

1985 ◽  
Vol 20 (3) ◽  
pp. 101-115
Author(s):  
James E. Lawler ◽  
Ronald H. Cox
Keyword(s):  
Environmental Factors ◽  
New Model ◽  
Hypertensive Rat

The renal endothelin system in the Prague hypertensive rat, a new model of spontaneous hypertension

1999 ◽  
Vol 97 (1) ◽  
pp. 91 ◽  
Author(s):  
Volker VOGEL ◽  
Angela BÄCKER ◽  
Jiri HELLER ◽  
Herbert J. KRAMER
Keyword(s):  
Spontaneous Hypertension ◽  
New Model ◽  
Hypertensive Rat ◽  
Endothelin System ◽  
Prague Hypertensive Rat

The renal endothelin system in the Prague hypertensive rat, a new model of spontaneous hypertension

1999 ◽  
Vol 97 (1) ◽  
pp. 91-98 ◽  
Author(s):  
Volker VOGEL ◽  
Angela BÄCKER ◽  
Jiri HELLER ◽  
Herbert J. KRAMER
Keyword(s):  
Renal Cortex ◽  
Renal Tissue ◽  
Spontaneous Hypertension ◽  
Mrna Levels ◽  
New Model ◽  
Total Rna ◽  
Peptide Concentration ◽  
Hypertensive Rat ◽  
Mrna Content ◽  
Prague Hypertensive Rat

In a new model of spontaneous hypertension, namely the Prague hypertensive rat (PHR), hypertension is transferred with a kidney transplanted from the PHR to its normotensive counterpart (PNR) by an as yet unknown mechanism. One candidate may be endothelin (ET), since this potent vasoconstrictor affects vascular tone, renal haemodynamics and renal excretory function, and all members of this peptide family are located within the kidney and act in an autocrine/paracrine fashion. In the present study we investigated, in the renal tissue of PHRs and PNRs: (1) preproET-1 and preproET-3 mRNAs as well as ET-1 and ET-3 peptide distribution, (2) endothelin-converting enzyme (ECE)-1 mRNA expression, and (3) ET receptors and their characteristics in membranes of glomeruli and papillae. In addition, plasma ET concentration and urinary ET excretion were determined. Quantitative measurements by competitive reverse transcription-polymerase chain reaction revealed ET-1 mRNA levels in the renal cortex from PHRs and PNRs of 1.09±0.13 and 1.29±0.18 amol/µg of total RNA respectively, and in red medulla of 2.72±0.82 and 3.30±0.68 amol/µg respectively. In contrast, renal papilla from PHRs showed significantly lower levels of preproET-1 mRNA (1.81±0.64 amol/µg of total RNA, compared with 4.25±0.82 amol/µg in PNRs; each n = 5; P< 0.05). The ET-1 peptide concentration in papillary tissue was also significantly lower in PHRs than in PNRs (120.2±30.8 and 491.3±53.4 fmol/mg of protein respectively; n = 5; P< 0.01), whereas it was similar in cortex and medulla from PHRs and PNRs. The preproET-3 mRNA content in renal tissue was much lower than that of preproET-1 mRNA. It was significantly higher in red medulla from PHRs compared with that from PNRs (0.25±0.05 and 0.13±0.02 amol/µg of total RNA respectively; P< 0.05), but was similar in papillae of PHRs and PNRs (0.04±0.02 and 0.05±0.01 amol/µg respectively; n = 5). Cortical preproET-3 mRNA was at the lower limit of detection. Similarly, the ET-3 peptide concentration was slightly but significantly higher in the red medulla of PHRs compared with PNRs (15.4±2.0 and 8.8±0.8 fmol/mg of protein respectively; n = 5; P< 0.05), whereas no differences in ET-3 peptide concentration were found in papillae from PHRs and PNRs. ECE-1 mRNA levels were similar in the renal cortex, red medulla and papillae from PHRs and PNRs, ranging between 0.34±0.03 and 0.56±0.12 amol/µg of total RNA. Of the total ET receptors in glomerular membranes, 39% were ETA receptors, whereas papillary membranes contained exclusively ETB receptors. PHRs and PNRs showed similar Bmax and Kd values for ET-1 in renal glomerular membranes (Bmax, 6.5±1.3 and 4.9±1.2 pmol/mg of protein respectively; Kd, 0.69±0.10 and 0.56±0.10 nM respectively) and papillary membranes (Bmax, 9.7±1.1 and 11.3±1.6 pmol/mg of protein respectively; Kd, 0.30±0.04 and 0.42±0.07 nM respectively). Plasma ET-1/2 concentrations (10.4±1.3 and 12.2±1.2 fmol/ml in PHRs and PNRs respectively) and urinary ET-1 excretion (3.1±0.3 and 3.0±0.2 pmol/24 h in PHRs and PNRs respectively) were similar in hypertensive and normotensive rats. In summary, although tissue levels of preproET-3 mRNA were very low in the kidney, significantly greater amounts of preproET-3 mRNA and ET-3 peptide were found in medullary tissue from PHRs compared with PNRs, a finding that awaits further investigation. In contrast, the preproET-1 mRNA content and ET-1 peptide concentration were significantly lower in papillary tissue from PHRs compared with PNRs. Decreased synthesis of ET-1, which normally antagonizes the action of [Arg8]vasopressin, may allow increased water (and sodium) reabsorption at the level of the inner medullary collecting duct. This intrinsic defect of the kidney in the PHR may contribute to hypertension in this model, and may transmit high blood pressure on transplantation of the ‘hypertensive’ kidney into a normotensive rat.

The Relocation Experience: Analysis of Factors Thought to Influence Adjustment to Transition

1992 ◽  
Vol 70 (3) ◽  
pp. 835-838 ◽  
Author(s):  
Pamela Lyn Carlisle-Frank
Keyword(s):  
Environmental Factors ◽  
Review Of The Literature ◽  
New Model ◽  
Factors Associated

This paper provides an overview of the literature on the psychological, sociological, and environmental factors associated with relocation. From this review of the literature several hypotheses have been abstracted and are suggested for further study. A new model is also presented which examines these factors in relation to their influence on adjustment to transition.

The Prague Hypertensive Rat: A New Model of Genetic Hypertension

1993 ◽  
Vol 15 (5) ◽  
pp. 807-818 ◽  
Author(s):  
J. Heller ◽  
S. Hellerová ◽  
Z. Dobesková ◽  
J. Kunes ◽  
J. Zicha
Keyword(s):  
New Model ◽  
Genetic Hypertension ◽  
Hypertensive Rat ◽  
Prague Hypertensive Rat

Development of a new model for combined atherosclerosis and hypertension: ApoE-knockout spontaneously hypertensive rat

2017 ◽  
Vol 263 ◽  
pp. e86
Author(s):  
Hiroyuki Matsuo ◽  
Takehito Kaneko ◽  
Koichi Fujikawa ◽  
Hiroki Ohara ◽  
Tomoji Mashimo ◽  
...  
Keyword(s):  
Spontaneously Hypertensive Rat ◽  
Spontaneously Hypertensive ◽  
New Model ◽  
Hypertensive Rat

Reductionist thinking and animal models in neuropsychiatric research

2019 ◽  
Vol 42 ◽  
Author(s):  
Nicole M. Baran
Keyword(s):  
Animal Models ◽  
Mental Disorders ◽  
Environmental Factors ◽  
Neuropsychiatric Disorders ◽  
Model Organisms ◽  
Developmental Genetic ◽  
Term Study ◽  
Genetic And Environmental Factors ◽  
Mechanisms Of Plasticity

AbstractReductionist thinking in neuroscience is manifest in the widespread use of animal models of neuropsychiatric disorders. Broader investigations of diverse behaviors in non-model organisms and longer-term study of the mechanisms of plasticity will yield fundamental insights into the neurobiological, developmental, genetic, and environmental factors contributing to the “massively multifactorial system networks” which go awry in mental disorders.

The Hitachi Model HS-8 Electron Microscope

1967 ◽  
Vol 25 ◽  
pp. 238-239
Author(s):  
H. Akabori ◽  
K. Nishiwaki ◽  
K. Yoneta
Keyword(s):  
Electron Microscope ◽  
New Model ◽  
Predecessor Model

By improving the predecessor Model HS- 7 electron microscope for the purpose of easier operation, we have recently completed new Model HS-8 electron microscope featuring higher performance and ease of operation.

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