scholarly journals Ventilatory phenotypes among four strains of adult rats

2002 ◽  
Vol 93 (3) ◽  
pp. 974-983 ◽  
Author(s):  
Matthew R. Hodges ◽  
Hubert V. Forster ◽  
Paula E. Papanek ◽  
Melinda R. Dwinell ◽  
Genevieve E. Hogan
Keyword(s):  
Ventilatory Response ◽  
Strain Difference ◽  
Strain Differences ◽  
Inbred Strains ◽  
The Other ◽  
Brown Norway ◽  
Control Mechanisms ◽  
Sprague Dawley ◽  
Adult Rats ◽  
Different Strains

Our purpose in this study was to identify different ventilatory phenotypes among four different strains of rats. We examined 114 rats from three in-house, inbred strains and one outbred strain: Brown Norway (BN; n = 26), Dahl salt-sensitive ( n = 24), Fawn-hooded Hypertensive (FHH: n = 27), and outbred Sprague-Dawley rats (SD; n = 37). We measured eupneic (room air) breathing and the ventilatory responses to hypoxia (12% O2-88% N2), hypercapnia (7% CO2), and two levels of submaximal exercise. Primary strain differences were between BN and the other strains. BN rats had a relatively attenuated ventilatory response to CO2 ( P < 0.001), an accentuated ventilatory response to exercise ( P < 0.05), and an accentuated ventilatory roll-off during hypoxia ( P < 0.05). Ventilation during hypoxia was lower than other strains, but hyperventilation during hypoxia was equal to the other strains ( P > 0.05), indicating that the metabolic rate during hypoxia decreased more in BN rats than in other strains. Another strain difference was in the frequency and timing components of augmented breaths, where FHH rats frequently differed from the other strains, and the BN rats had the longest expiratory time of the augmented breaths (probably secondary to the blunted CO2 sensitivity). These strain differences not only provide insight into physiological mechanisms but also indicate traits (such as CO2 sensitivity) that are genetically regulated. Finally, the data establish a foundation for physiological genomic studies aimed at elucidating the genetics of these ventilatory control mechanisms.

Strain difference in thermoregulation of rats surviving extreme heat

1982 ◽  
Vol 52 (2) ◽  
pp. 410-415 ◽  
Author(s):  
F. Furuyama
Keyword(s):  
Body Temperature ◽  
Heat Tolerance ◽  
Strain Difference ◽  
Body Weight Loss ◽  
The Body ◽  
Sprague Dawley ◽  
Survival Times ◽  
Sprague Dawley Rats ◽  
Thermoregulatory System ◽  
Different Strains

The survival times of unanesthetized rats in 42.5 degree C. 48% rh were studied in 12 different strains. In males, Sprague-Dawley rats (P less than 0.01) and Fisher 344/MK (P less than 0.05) showed significantly higher heat tolerance than the other 9 strains. Among Sprague-Dawley rats, females tolerated heat longer than males (P less than 0.05). There was no difference in lethal body temperature according to strains and exposure temperatures (38.5–48.5 degree C). Maximum survivable body temperature was 43.1 degree C in males and 43.3 degree C in females. The body weight loss in heat was greater in Sprague-Dawley, Fisher 344/MK, and JCL:Wistar strains. The degree of saliva spreading during the equilibrium period just below the maximum survivable body temperature correlated significantly with heat tolerance and was found to be the index of strain difference in heat tolerance. These findings demonstrated that the thermoregulatory system of rats is controlled genetically, though survival times of individuals in different strains sometimes overlap.

scholarly journals Potentiation of hypoxic ventilatory response by hyperoxia in the conscious rat: putative role of nitric oxide

1998 ◽  
Vol 85 (1) ◽  
pp. 129-132 ◽  
Author(s):  
David Gozal
Keyword(s):  
Nitric Oxide ◽  
Ventilatory Response ◽  
Minute Ventilation ◽  
Hypoxic Ventilatory Response ◽  
Sprague Dawley ◽  
Conscious Rat ◽  
Adult Rats ◽  
Hyperoxic Exposure ◽  
Essential Components ◽  
Oxide Synthase

In humans, the hypoxic ventilatory response (HVR) is augmented when preceded by a short hyperoxic exposure (Y. Honda, H. Tani, A. Masuda, T. Kobayashi, T. Nishino, H. Kimura, S. Masuyama, and T. Kuriyama. J. Appl. Physiol. 81: 1627–1632, 1996). To examine whether neuronal nitric oxide synthase (nNOS) is involved in such hyperoxia-induced HVR potentiation, 17 male Sprague-Dawley adult rats underwent hypoxic challenges (10% O2-5% CO2-balance N2) preceded either by 10 min of room air (−O2) or of 100% O2(+O2). At least 48 h later, similar challenges were performed after the animals received the selective nNOS inhibitor 7-nitroindazole (25 mg/kg ip). In −O2 runs, minute ventilation (V˙e) increased from 121.3 ± 20.5 (SD) ml/min in room air to 191.7 ± 23.8 ml/min in hypoxia ( P< 0.01). After +O2,V˙e increased from 114.1 ± 19.8 ml/min in room air to 218.4 ± 47.0 ml/min in hypoxia (+O2 vs. −O2: P < 0.005, ANOVA). After 7-nitroindazole administration, HVR was not affected in the −O2 treatment group withV˙e increasing from 113.7 ± 17.8 ml/min in room air to 185.8 ± 35.0 ml/min in hypoxia ( P < 0.01). However, HVR potentiation in +O2-exposed animals was abolished (111.8 ± 18.0 ml/min in room air to 184.1 ± 35.6 ml/min in hypoxia; +O2 vs. −O2: P not significant). We conclude that in the conscious rat nNOS activation mediates essential components of the HVR potentiation elicited by a previous short hyperoxic exposure.

scholarly journals Ventilatory responses to ozone are reduced in immature rats

2000 ◽  
Vol 88 (6) ◽  
pp. 2023-2030 ◽  
Author(s):  
S. A. Shore ◽  
J. H. Abraham ◽  
I. N. Schwartzman ◽  
G. G. Krishna Murthy ◽  
J. D. Laporte
Keyword(s):  
Bronchoalveolar Lavage ◽  
Ventilatory Response ◽  
Minute Ventilation ◽  
Sprague Dawley ◽  
Adult Rats ◽  
Ventilatory Responses ◽  
Sprague Dawley Rats ◽  
Immature Rats ◽  
Old Rats ◽  
Induced Changes

During ozone (O3) exposure, adult rats decrease their minute ventilation (V˙e). To determine whether such changes are also observed in immature animals, Sprague-Dawley rats, aged 2, 4, 6, 8, or 12 wk, were exposed to O3(2 ppm) in nose-only-exposure plethysmographs. BaselineV˙e normalized for body weight decreased with age from 2.1 ± 0.1 ml ⋅ min−1⋅ g−1in 2-wk-old rats to 0.72 ± 0.03 ml ⋅ min−1⋅ g−1in 12-wk-old rats, consistent with the higher metabolic rates of younger animals. In adult (8- and 12-wk-old) rats, O3caused 40–50% decreases in V˙e that occurred primarily as the result of a decrease in tidal volume. In 6-wk-old rats, O3-induced changes inV˙e were significantly less, and in 2- and 4-wk-old rats, no significant changes inV˙e were observed during O3exposure. The increased baseline V˙e and the smaller decrements in V˙e induced by O3in the immature rats imply that their delivered dose of O3is much higher than in adult rats. To determine whether these differences in O3dose influence the extent of injury, we measured bronchoalveolar lavage protein concentrations. The magnitude of the changes in bronchoalveolar lavage induced by O3was significantly greater in 2- than in 8-wk-old rats (267 ± 47 vs. 165 ± 22%, respectively, P < 0.05). O3exposure also caused a significant increase in PGE2in 2-wk-old but not in adult rats. The results indicate that the ventilatory response to O3is absent in 2-wk-old rats and that lack of this response, in conjunction with a greater specific ventilation, leads to greater lung injury.

scholarly journals Sex-specific constitutive expression of the pre-neoplastic marker glutathione S-transferase, YfYf, in mouse liver

1987 ◽  
Vol 245 (2) ◽  
pp. 399-406 ◽  
Author(s):  
L I McLellan ◽  
J D Hayes
Keyword(s):  
Mouse Liver ◽  
Constitutive Expression ◽  
Strain Differences ◽  
Inbred Strains ◽  
Glutathione S Transferase ◽  
Enzyme Form ◽  
Apparent Homogeneity ◽  
Different Strains ◽  
The Individual ◽  
A Minor

Hepatic glutathione S-transferase isoenzyme content has been investigated in both sexes of three inbred strains of mice (DBA/2, C3H/He, C57BL6). A polypeptide (Mr 24,800), which is immunologically related to Yf purified from rat lung, was found to be expressed as a major form in all male mouse livers but represented only a minor enzyme form in female mouse liver. Glutathione S-transferases comprising subunits with molecular masses of 25,800 (Ya) or 26,400 (Yb) were present in males and females of the three strains under investigation. Cytosolic isoenzymes from all strains and sexes were purified to apparent homogeneity and no significant inter-strain differences in the properties of the individual forms were observed. In addition, no differences were detected in the microsomal glutathione S-transferase content of the different strains or sexes.

GENETIC VARIATION IN ADRENAL STRUCTURE: QUANTITATIVE MEASUREMENTS ON THE CORTEX AND MEDULLA IN HYBRID MICE

1970 ◽  
Vol 48 (3) ◽  
pp. 419-431 ◽  
Author(s):  
J. G. M. SHIRE
Keyword(s):  
Genetic Variation ◽  
Adrenal Cortex ◽  
Strain Difference ◽  
Natural Populations ◽  
Strain Differences ◽  
Inbred Strains ◽  
Zona Fasciculata ◽  
Testis Weight ◽  
Cortical Volume ◽  
Cba Mice

SUMMARY The volumes of the adrenal cortex and medulla were measured for young adult male mice from the A/Cam and CBA/FaCam strains and from five hybrid generations produced by crossing these inbred strains. The hybrid stocks were the reciprocal F1's, the F2 and the backcrosses to both parental strains. Two independent sets of measurements were made. The second set confirmed and extended the results of the first. Both the adrenal cortex and the adrenal medulla were significantly larger in the CBA mice than they were in the A mice. It seems likely that the observed difference between the strains in cortical volume was determined by genetic variation either at a single locus or, at most, at two loci. The difference in medullary volume was determined by variation at at least two gene loci. In all cases the alleles found in the CBA mice showed dominance. The problems of deciding whether four separate loci were involved or whether all the differences were due to pleiotropic effects of fewer genes is discussed. In the first experiment measurements of the volume and number of cells in the zona fasciculata were made in addition to those of medullary and cortical volume. These measurements confirmed the existence of genetic variation in these characters which had been suggested by earlier findings of significant strain differences in them. The results of the second experiment also showed that the significant strain difference between A and CBA mice in testis weight was brought about by genes other than those causing the adrenal differences. The relation between the differences in adrenal structure described in this paper and those known to exist between these two strains in other aspects of the adrenal glands and in their target organs are discussed, as is the relation between findings on inbred strains and those to be expected in natural populations.

Abstract P089: Assessment Of Sensorimotor Function To Establish A Clinically Relevant Animal Model Of Intracerebral Hemorrhage (ICH) Using The Hypertensive Transgenic Rat (mRen2)27

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Nicholas J Contillo ◽  
Anthony Anzalone ◽  
Nathan McMullen ◽  
Keyan Peterson ◽  
Christine Tschoe ◽  
...  
Keyword(s):  
Animal Model ◽  
Strong Predictor ◽  
Strain Difference ◽  
Strain Differences ◽  
Uncontrolled Hypertension ◽  
Transgenic Rat ◽  
Sprague Dawley ◽  
Relevant Animal Model ◽  
Inflammatory State ◽  
Poor Outcomes

Uncontrolled hypertension is the leading cause of spontaneous ICH and elevated SBP is a strong predictor of poor outcomes in ICH patients. An animal model of the chronically hypertensive, metabolically dysfunctional and pro-inflammatory state of the ICH patient population is needed to advance clinically-relevant ICH research. Transgenic (mRen2)27 rats overexpress the murine Ren2 gene and develop hypertension and metabolic syndrome by 12-14 weeks of age. Indices of diastolic and systolic cardiac function are in decline in (mRen2)27 males by 30 weeks of age, but are preserved in females at this age. To establish whether (mRen2)27 rats exhibit sensorimotor dysfunction as compared with control Sprague Dawley (SD) rats, male and female (mRen2)27 rats underwent corner turn (CT), vibrissae evoked forelimb placing (VEF), cage wire hang (CWH), and open-field (OF) testing for five consecutive weeks starting at 20-weeks of age (n=16; female=8; each strain). Despite the significant between-strain difference in SBP [189 ± 3 mmHg in (mRen2)27 and 119 ± 3 mmHg in SD; p<0.001], there were no significant between-strain differences in sensorimotor testing at weeks 20, 22, 23, and 24 (Table 1). At week 21, a significant between-strain difference was identified isolated to the VEF test (p<0.01). As sensorimotor testing is critical to assess the effect of experimentally-induced ICH in rodent models, the lack of strain differences supports the viability of (mRen2)27 rats as a clinically relevant model for the comparison of ICH superimposition in the two strains at this age without consistent baseline sensorimotor deficits. (Cardiovascular Sci. and Hypertension & Vasc. Res. Ctrs; Neurosurgery)

scholarly journals Postnatal developmental changes in CO2 sensitivity in rats

2006 ◽  
Vol 101 (4) ◽  
pp. 1097-1103 ◽  
Author(s):  
S. E. Davis ◽  
G. Solhied ◽  
M. Castillo ◽  
M. Dwinell ◽  
D. Brozoski ◽  
...  
Keyword(s):  
Pulmonary Ventilation ◽  
Strain Differences ◽  
Developmental Changes ◽  
Brown Norway ◽  
Sprague Dawley ◽  
Dependent Plasticity ◽  
Co2 Sensitivity ◽  
Age Dependent ◽  
High Degree ◽  
Physiological Systems

Ventilatory sensitivity to CO2 in awake adult Brown Norway (BN) rats is 50–75% lower than in adult Sprague-Dawley (SD) and salt-sensitive Dahl S (SS) rats. The purpose of the present study was to test the hypothesis that this difference would be apparent during the development of CO2 sensitivity. Four litters of each strain were divided into four groups such that rats were exposed to 7% inspired CO2 for 5 min in a plethysmograph every third day from postnatal day (P) 0 to P21 and again on P29 and P30. From P0 to P14, CO2 exposure increased pulmonary ventilation (V̇e) by 25–50% in the BN and SD strains and between 25 to over 200% in the SS strain. In all strains beginning around P15, the response to CO2 increased progressively reaching a peak at P19–21 when V̇e during hypercapnia was 175–225% above eucapnia. There were minimal changes in CO2 sensitivity between P21 and P30, and at both ages there were minimal between-strain differences. At P30, the response to CO2 in the SS and SD strains was near the adult response, but the response in the BN rats was 100% greater at P30 than in adults. We conclude that 1) CO2-sensing mechanisms, and/or mechanisms downstream from the chemoreceptors, change dramatically at the age in rats when other physiological systems are also maturing (∼P15), and 2) there is a high degree of age-dependent plasticity in CO2 sensitivity in rats, which differs between strains.

scholarly journals Strain differences in the activities of rat liver enzymes

1969 ◽  
Vol 114 (4) ◽  
pp. 877-879 ◽  
Author(s):  
L. V. Eggleston ◽  
H. A. Krebs
Keyword(s):  
Pyruvate Kinase ◽  
Rat Liver ◽  
Liver Enzymes ◽  
Strain Differences ◽  
Soluble Carbohydrate ◽  
Sprague Dawley ◽  
Major Strain ◽  
Glycerophosphate Dehydrogenase ◽  
Glyceraldehyde Phosphate Dehydrogenase ◽  
Different Strains

1. The activities of four enzymes of glycolysis were assayed in the liver of five different strains of rats (four ‘Wistar-derived’, one Sprague–Dawley) kept on three different but very similar diets. 2. Major strain differences were found for the activities of pyruvate kinase (3-fold), α-glycerophosphate dehydrogenase (5-fold), glyceraldehyde phosphate dehydrogenase (3-fold) and triokinase (1·5-fold). 3. Although the initial activities of pyruvate kinase differed greatly the percentage responses to starvation or a diet high in soluble carbohydrate were of the same order in two strains. 4. The importance of considering strain differences is emphasized when making comparisons of measurements carried out in different laboratories.

Myocardial lesions in rats fed rapeseed oil. I. Influence of strain of rats

1977 ◽  
Vol 55 (2) ◽  
pp. 258-264 ◽  
Author(s):  
H. W. Hulan ◽  
J. K. G. Kramer ◽  
A. H. Corner
Keyword(s):  
Fatty Acid Composition ◽  
Rapeseed Oil ◽  
Corn Oil ◽  
The Other ◽  
Sprague Dawley ◽  
High Incidence ◽  
Two Factors ◽  
Ad Libitum ◽  
Different Strains ◽  
Myocardial Lesions

The influence of strain of rat on the development of myocardial lesions was investigated in an experiment which included two factors: strain (Wistar, Sherman, Chester Beatty (Hooded), and Sprague–Dawley from two sources designated Sprague–Dawley A, Sprague–Dawley C) and diet (5% corn oil, 20% corn oil, and 20% Brassica napus var. Zephyr rapeseed oil). Groups of 30 rats, housed 2 per cage, from each of three different strains of rats and groups of 10 rats, housed 2 per cage, from one strain of rats (Hooded) were fed semisynthetic diets containing the test oils for 16 weeks on an ad libitum basis. Rats of the Hooded strain consumed considerably less feed and grew at a significantly (P < 0.01) slower rate than did rats of the Sprague–Dawley C strain, which in turn ate less and grew significantly (P < 0.01) slower than rats of the other three strains. No marked differences were observed in the fatty acid composition of total cardiac lipids among strains. Rats from all strains except Hooded fed the diet containing 20% Zephyr RSO had a significantly (P < 0.001) higher incidence of myocardial lesions than rats fed the 20% corn oil diet which in turn had a significantly (P < 0.001) higher incidence than rats fed 5% corn oil. Similarly, significantly (P < 0.05) more Sprague–Dawley C rats had myocardial lesions than Sprague–Dawley A rats regardless of diet. None of the Hooded rats fed the diet containing 20% Zephyr RSO developed myocardial lesions whereas all other strains fed this diet developed a high incidence of myocardial lesions.

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