Phenotype Data & Protocol Description



The phenotyping component provides 213 phenotypic measurements of heart, lung, vascular, and blood function. Each strain enters the protocols allowing for the functional characterization of both genders and parental control rats over a 5-week period. The data will provide the functional information required to link each of the rats 22 chromosomes to cardiovascular, pulmonary, renal and blood function. The following are the brief descriptions of each of the phenotyping protocols. Click on the protocol name to view the phenotypes measured in this protocol.


Protocol NameProtocol DescriptionNum. of Phenotypes
Protocol A was designed to characterize arterial blood pressure, blood pressure-related phenotypes, and the susceptibility to developing renal injury in response to a high salt diet in 12-week old rats. Protocol duration was 2 weeks.
Diet-Rats were weaned onto low salt, 0.4% NaCl, diet (Dyets or Teklad, depending on the date of the study) and switched to high salt, 4.0% NaCl, diet (Dyets or Teklad, depending on the date of the study) 21 days prior to study; Atmosphere - Normoxia. Diet of the parents was low salt, 0.4% NaCl, (either Teklad or Dyets, depending on the date of the study). In addition, FHH.BN consomic and appropriate parental groups received the nitric oxide synthase inhibitor N-nitro-L-arginine methyl ester (L-NAME; 25mg/L) in drinking water for 21 days prior to the phenotyping protocol.Click here to see the detailed RENAL_A protocol. Please click here for a statement about diet effects. Please click here for an explanation about important changes in the Renal Protocol.
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The objectives of this protocol are to characterize respiratory control mechanisms and the pattern of breathing and lung function in the conscious state under acute conditions of hypoxia, hypercapnia and exercise. Hypercapnia is 7% inspired CO2. The acute exercise study compares conscious animals at rest, walking, and running. 2 week conditioning:
Diet - Low salt 0.4% NaCl; Atmosphere - Normoxia. Click here to see the detailed
respiratory protocol, and click here to see the protocol revised on February 4th, 2004.
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The objectives of this protocol are to quantify strain differences in airway methacholine
sensitivity, pulmonary vascular mechanics, pulmonary endothelial angiotensin converting
enzyme activity, and pulmonary endothelial redox status in normal and chronically hypoxic
rats. 2 week conditioning: Diet - Low salt 0.4% NaCl; Atmosphere - Normoxia or 2 week
conditioning: Diet - Low salt 0.4% NaCl; Atmosphere - Hypoxia, 12% inspired O2. Click here to see the detailed lung protocol
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The objectives of this protocol are to uncover phenotypic differences between consomic and
parental strains in the mechanical, electrical and biochemical function in the aerobically
perfused isolated heart and in the ability of the isolated heart to resist coronary ischemia. 2
week conditioning: Diet - Low salt 0.4% NaCl; Atmosphere - Normoxia or 2 week
conditioning:Diet-Low salt 0.4% NaCl; Atmosphere - Hypoxia, 12% inspired O2. Click here
to see the detailed cardiac protocol
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The objectives of this protocol are to characterize vascular responsiveness to acute
vasoconstrictors and dilators; to assess vascular function and the susceptibility developing
injury in response to a high salt diet. 3 week conditioning: Diet - Low salt 0.4% NaCl;
Atmosphere - Normoxia or 3 week conditioning: Diet -High salt 4.0% NaCl; Atmosphere -
Normoxia. Click here to see the detailed vascular protocol
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The objectives of the biochemistry study are to characterize indices of clinical chemistry,
hematology in normoxic and chronically hypoxic rats. Samples are taken from the Lung
protocol animals following 2 week conditioning: Diet - Low salt 0.4% NaCl;Atmosphere -
Normoxia or 2 week conditioning: Diet - Low salt 0.4% NaCl; Atmosphere - Hypoxia, 12%
inspired O2. Click here to see the detailed Biochemistry protocol
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Tissues will be collected from the heart, kidney and aorta from each of the consomic and parental strains. Animals will be conditioned for two weeks under hypoxic conditions, and three weeks under normoxic, high salt or high salt plus L-N conditions. The tissues will be examined for gross abnormalities and then histological sections will be prepared and will be made available for investigators to examine via digital images and/or tissue sample request. 3 week conditioning:Diet - Low salt 0.4% NaCl; Atmosphere - Normoxia or 3 week conditioning: Diet - High salt 4.0% NaCl; Atmosphere - Normoxia or 3 week conditioning: Diet - High salt 4.0% NaCl with last 10 days adding L-N(12mg/L) in drinking water; Atmosphere - Normoxia or 2 weeks conditioning: Diet - Low salt 0.4% NaCl;Atmosphere - Hypoxia,12% inspired O2. Click here to see the detailed histology protocol3
Protocol B was then designed to provide a standardized revaluation of all rat strains that had been previously studied. The protocol was therefore streamlined into a 1-week study. Differences in phenotype occurred that were dependent upon the diet provided to the rats. For example, rats fed 4.0% NaCl Dyets became morehypertensive and proteinuric than rats fed 4.0% Teklad. These differences were discovered when diets were changed in an effort to improve the efficiency of breeding.
Diet - Rats are weaned onto low salt diet (0.4% NaCl; Dyets) and switched to high salt diet (8.0% NaCl; Dyets) 17 days prior to study; atmosphere - Normoxia. Diet of the parents is 0.4% NaCl Teklad chow. In addition, FHH.BN consomic and appropriate parental groups receive the nitric oxide synthase inhibitor N-nitro-L-arginine methyl ester (L-NAME; 12mg/L) in drinking water for 17 days prior to the phenotyping protocol. Click here to see the detailed RENAL_B protocol. Please click here for a statement about diet effects. Please click here for an explanation about important changes in the Renal Protocol.
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