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Aging and in vitro vascular responses to endothelin-1 in several rat strains.

https://arctichealth.org/en/permalink/ahliterature11658
Source
Pharmacol Res. 1993 Oct-Nov;28(3):193-202
Publication Type
Article
Author
A. Filippelli
A. Palla
E. Lampa
F. Rossi
Author Affiliation
Institute of Pharmacology and Toxicology, Faculty of Medicine and Surgery, 2nd University of Naples, Italy.
Source
Pharmacol Res. 1993 Oct-Nov;28(3):193-202
Language
English
Publication Type
Article
Keywords
Aging - physiology
Animals
Aorta, Thoracic - drug effects
Blood Pressure - drug effects - physiology
Endothelins - pharmacology
Hyperlipidemia - blood - physiopathology
In Vitro
Lipids - blood
Muscle, Smooth, Vascular - drug effects
Norepinephrine - pharmacology
Rats
Rats, Inbred BN
Rats, Inbred SHR
Rats, Inbred Strains
Rats, Inbred WKY
Species Specificity
Abstract
The endothelins are a recently discovered family of potent contractile peptides produced by endothelial cells. These peptides have been suggested to play an important role in the pathogenesis of hypertension, myocardial infarction, cardiogenic shock, and so on. The aim of our study was to compare the responses to endothelin-1 (ET-1) with those to L-noradrenaline (NA) in aortic rings from rats of different strains and ages. Thoracic aorta rings from spontaneously hypertensive (SHR), Wistar Kyoto (WKY), Brown Norway (BN) and spontaneously hyperlipemic (Yoshida, YOS) rats 2-4 (young), 6-8 (adult) and 20-25 (old) months old were used. There were no changes in the pD2 values for ET-1 and NA between WKY and SHR rats at the ages studied. The ET-1 and NA Emax in adult SHR rats was significantly lower than in the age-matched WKY animals. Old age reduced the ET-1 and NA Emax in both SHR and WKY rats abolishing the difference observed at 6-8 months in the same groups. The reactivity to ET-1 and NA of BN and YOS rats was modified only in young rats. In YOS strain aging did not modify the ET-1 and NA responses as the pD2 and Emax values remained unchanged. Our findings demonstrate that ET-1 is a more potent vasoconstrictor than NA and that this potency remains unchanged throughout the ages and the pathologies studied. In contrast, the pD2 of NA decreases with old age in SHR and WKY rats. We conclude that rat strain but not hypertension or hyperlipemia can modify the response to ET-1 or NA in old age. We suppose that this functional change may involve alterations in the responsiveness of vascular smooth muscle.
PubMed ID
8108309 View in PubMed
Less detail

Apelin, the novel endogenous ligand of the orphan receptor APJ, regulates cardiac contractility.

https://arctichealth.org/en/permalink/ahliterature9913
Source
Circ Res. 2002 Sep 6;91(5):434-40
Publication Type
Article
Date
Sep-6-2002
Author
István Szokodi
Pasi Tavi
Gábor Földes
Sari Voutilainen-Myllylä
Mika Ilves
Heikki Tokola
Sampsa Pikkarainen
Jarkko Piuhola
Jaana Rysä
Miklós Tóth
Heikki Ruskoaho
Author Affiliation
Department of Pharmacology and Toxicology, Biocenter Oulu, University of Oulu, Oulu, Finland.
Source
Circ Res. 2002 Sep 6;91(5):434-40
Date
Sep-6-2002
Language
English
Publication Type
Article
Keywords
Animals
Animals, Genetically Modified
Calcium Channels - physiology
Carrier Proteins - genetics - metabolism - pharmacology
Dose-Response Relationship, Drug
Endothelin-1 - pharmacology
Gene Expression Regulation
Heart Ventricles - cytology - drug effects - physiology
In Vitro
Isoproterenol - pharmacology
Ligands
Male
Membrane Potentials - drug effects
Myocardial Contraction - drug effects
Peptides - pharmacology
Potassium Channels - physiology
RNA, Messenger - genetics - metabolism
Rats
Rats, Inbred SHR
Rats, Inbred WKY
Rats, Sprague-Dawley
Receptors, Dopamine D2 - genetics - metabolism
Receptors, G-Protein-Coupled
Research Support, Non-U.S. Gov't
Sodium-Calcium Exchanger - metabolism
Sodium-Hydrogen Antiporter - metabolism
Stress, mechanical
Time Factors
Abstract
The orphan receptor APJ and its recently identified endogenous ligand, apelin, exhibit high levels of mRNA expression in the heart. However, the functional importance of apelin in the cardiovascular system is not known. In isolated perfused rat hearts, infusion of apelin (0.01 to 10 nmol/L) induced a dose-dependent positive inotropic effect (EC50: 33.1+/-1.5 pmol/L). Moreover, preload-induced increase in dP/dt(max) was significantly augmented (P
PubMed ID
12215493 View in PubMed
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Brain corticotropin-releasing factor immunoreactivity and receptors in five inbred rat strains: relationship to forced swimming behaviour.

https://arctichealth.org/en/permalink/ahliterature46408
Source
Brain Res. 1997 Mar 7;750(1-2):285-92
Publication Type
Article
Date
Mar-7-1997
Author
A. Lahmame
D E Grigoriadis
E B De Souza
A. Armario
Author Affiliation
Departament de Biologia Cellular i de Fisiologia, Facultat de Ciències, Universitat Autònoma de Barcelona, Spain.
Source
Brain Res. 1997 Mar 7;750(1-2):285-92
Date
Mar-7-1997
Language
English
Publication Type
Article
Keywords
Animals
Brain - metabolism
Corticotropin-Releasing Hormone - metabolism
Depression
Hippocampus - metabolism
Medulla Oblongata - metabolism
Organ Specificity
Pons - metabolism
Prefrontal Cortex - metabolism
Rats
Rats, Inbred BN
Rats, Inbred F344
Rats, Inbred Lew
Rats, Inbred SHR
Rats, Inbred WKY
Receptors, Corticotropin-Releasing Hormone - metabolism
Research Support, Non-U.S. Gov't
Restraint, Physical
Species Specificity
Stress, Psychological
Swimming
Abstract
In the present work we studied the relationship between behaviour in the forced swimming test (FST), a test that presumably measures depressive-like behaviour in rodents, and central corticotropin-releasing factor (CRF) concentration and binding in five strains of rats. The strains were: Brown-Norway (BN), Fisher (FIS) 344, Lewis (LEW), spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). The FST data corresponding to the pretest showed significant inter-strain differences in both struggling and immobility: BN and WKY rats displayed lower levels of struggling and longer periods of immobility, LEW and SHR rats showed intermediate levels, and FIS rats were the most active. The results of the pretest were roughly similar to those observed in the test, the activity of WKY being extremely low. The CRF binding revealed significant inter-strain differences in prefrontal cortex and hippocampus, but not in cerebellum, pons-medulla or hypothalamus: in the prefrontal cortex, BN and FIS rats showed greater CRF binding than LEW, SHR and WKY rats; in the hippocampus BN rats showed higher levels of CRF binding than the other strains. The study of CRF content in various brain areas revealed inter-strain differences in prefrontal cortex and pons-medulla, but not in parietal-temporal cortex or in hypothalamus (CRF concentrations in the hippocampus were not detectable): CRF content in the prefrontal cortex was higher in BN than in the other strains, although the differences with FIS were not statistically significant; in the pons-medulla, FIS and LEW showed significantly higher CRF content than the other strains. From the present results it appears that BN and WKY rats were more prone to adopt passive strategies in the FST, but they did not show higher brain CRF immunoreactivity or down-regulation of CRF receptors. Hence, although there were inter-strains differences in all variables studied, no evidence for a relationship between the FST behaviour and central CRF activity was found.
PubMed ID
9098554 View in PubMed
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Brain natriuretic peptide in plasma, atria, and ventricles of vasopressin- and phenylephrine-infused conscious rats.

https://arctichealth.org/en/permalink/ahliterature11547
Source
Endocrinology. 1994 Jun;134(6):2505-15
Publication Type
Article
Date
Jun-1994
Author
J. Magga
M. Marttila
P. Mäntymaa
O. Vuolteenaho
H. Ruskoaho
Author Affiliation
Department of Pharmacology and Toxicology and Physiology, University of Oulu, Finland.
Source
Endocrinology. 1994 Jun;134(6):2505-15
Date
Jun-1994
Language
English
Publication Type
Article
Keywords
Animals
Argipressin - pharmacology
Heart Atria - metabolism
Heart Ventricles - metabolism
Hypertension - metabolism
Male
Myocardium - metabolism
Natriuretic Peptide, Brain
Nerve Tissue Proteins - blood - genetics - metabolism
Phenylephrine - pharmacology
RNA, Messenger - metabolism
Rats
Rats, Inbred SHR
Rats, Inbred WKY
Research Support, Non-U.S. Gov't
Abstract
To evaluate the mechanisms of brain natriuretic peptide (BNP) gene expression, we determined the effect of acute cardiac overload (from 30 min to 4 h) on atrial and ventricular BNP mRNA levels in normal and hypertrophied myocardium. Arginine8 vasopressin (AVP; 0.05 microgram/kg.min) and l-phenylephrine (PHE; 20 micrograms/kg.min) were infused iv to increase cardiac workload in conscious spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats. At the age of 10-22 months, during the established phase of ventricular hypertrophy, baseline BNP synthesis was increased in the hypertrophic ventricular cells of SHR, as reflected by about 2-fold (P
PubMed ID
8194476 View in PubMed
Less detail

Catecholamines in pericardial fluid of normotensive, spontaneously hypertensive and reserpine-treated rats.

https://arctichealth.org/en/permalink/ahliterature10702
Source
Acta Physiol Scand. 1999 Mar;165(3):293-7
Publication Type
Article
Date
Mar-1999
Author
R. Klemola
P. Huttunen
M. Laine
M. Weckström
J. Hirvonen
Author Affiliation
Department of Physiology, University of Oulu, Finland.
Source
Acta Physiol Scand. 1999 Mar;165(3):293-7
Date
Mar-1999
Language
English
Publication Type
Article
Keywords
Animals
Antihypertensive Agents - pharmacology
Heart - physiopathology
Hypertension - drug therapy - metabolism - physiopathology
Male
Norepinephrine - blood - metabolism - secretion
Pericardial Effusion - metabolism - physiopathology
Rats
Rats, Inbred SHR
Rats, Inbred WKY
Rats, Sprague-Dawley
Research Support, Non-U.S. Gov't
Reserpine - pharmacology
Abstract
In this study our aims were to investigate the presence and source of catecholamines in pericardial fluid of normotensive, reserpine-treated and spontaneously hypertensive rats. We found that noradrenaline is the only detectable catecholamine present in rat pericardial fluid. The effect of reserpine 6, 12, and 214 h after pre-treatment with 5 mg kg(-1) (8.2 micromol kg(-1)) i.p. shows that the concentration of noradrenaline in pericardial fluid reflects the amount of noradrenaline released within the heart rather than the amount of noradrenaline in plasma. Using spontaneously hypertensive rats (SHR) as a model for primary hypertension we could show that the level of pericardial noradrenaline is approximately threefold in the pericardial fluid of the SHRs when compared to respective values of age-matched normotensive Wistar-Kyoto rats (WKY), suggesting that there was an increased noradrenaline overflow in the hearts of the SHRs. In conclusion, determination of the noradrenaline concentration in the pericardial fluid might provide a new method for estimating the release of noradrenaline in the heart.
PubMed ID
10192179 View in PubMed
Less detail

[Characteristics of neuronal activity in nucleus accumbens in spontaneously hypertensive rats]

https://arctichealth.org/en/permalink/ahliterature77713
Source
Fiziol Zh. 2007;53(1):16-23
Publication Type
Article
Date
2007
Author
Lukhanina O P
Pil'kevych N O
Source
Fiziol Zh. 2007;53(1):16-23
Date
2007
Language
Ukrainian
Publication Type
Article
Keywords
Action Potentials - drug effects - physiology
Adrenergic beta-Agonists - administration & dosage - pharmacology
Animals
Hypertension - metabolism - physiopathology
Iontophoresis
Isoproterenol - administration & dosage - pharmacology
Microelectrodes
Neurons - drug effects - metabolism - physiology
Nucleus Accumbens - drug effects - metabolism - physiopathology
Rats
Rats, Inbred SHR
Rats, Wistar
Abstract
Spontaneously hypertensive rats (SHR) are generally considered as genetic model both for essential hypertension and attention-deficit hyperactivity syndrome. Neuroanatomical substrates and mechanisms of neural disorders in the SHR have not been elucidated. This study aimed to determine if the background impulse activity of Nucleus accumbens, core (NAc) neurons and their reactions evoked by amigdala stimulation in the SHR differ from those of normotensive Wistar rats (WR). Besides that we investigated the influence of microiontophoretic beta-adrenergic receptors agonist isoproterenol administration (5 mM solution; pH 5.0; 10-30 nA) on the NAc neuronal activity. Single unit extracellular recordings were performed under urethane anesthesia. These results showed that percentage of the NAc neurons with bursting discharge pattern of the background impulse activity is significantly (P
PubMed ID
17500198 View in PubMed
Less detail

Congenic strains provide evidence that four mapped loci in chromosomes 2, 4, and 16 influence hypertension in the SHR.

https://arctichealth.org/en/permalink/ahliterature90547
Source
Physiol Genomics. 2009 Mar 3;37(1):52-7
Publication Type
Article
Date
Mar-3-2009
Author
Aneas Ivy
Rodrigues Mariliza V
Pauletti Bianca A
Silva Gustavo J J
Carmona Renata
Cardoso Leandro
Kwitek Anne E
Jacob Howard J
Soler Julia M P
Krieger Jose E
Author Affiliation
Heart Institute (InCor), University of São Paulo Medical School, São Paulo, SP, Brazil.
Source
Physiol Genomics. 2009 Mar 3;37(1):52-7
Date
Mar-3-2009
Language
English
Publication Type
Article
Keywords
Animals
Animals, Congenic
Blood Pressure - drug effects - genetics
Chromosome Mapping
Chromosomes, Mammalian - genetics
Crosses, Genetic
Female
Hypertension - genetics - physiopathology
Male
Models, Genetic
Phenotype
Quantitative Trait Loci - genetics
Rats
Rats, Inbred SHR
Sodium Chloride, Dietary - administration & dosage - pharmacology
Systole - drug effects
Abstract
To dissect the genetic architecture controlling blood pressure (BP) regulation in the spontaneously hypertensive rat (SHR) we derived congenic rat strains for four previously mapped BP quantitative trait loci (QTLs) in chromosomes 2, 4, and 16. Target chromosomal regions from the Brown Norway rat (BN) averaging 13-29 cM were introgressed by marker-assisted breeding onto the SHR genome in 12 or 13 generations. Under normal salt intake, QTLs on chromosomes 2a, 2c, and 4 were associated with significant changes in systolic BP (13, 20, and 15 mmHg, respectively), whereas the QTL on chromosome 16 had no measurable effect. On high salt intake (1% NaCl in drinking water for 2 wk), the chromosome 16 QTL had a marked impact on SBP, as did the QTLs on chromosome 2a and 2c (18, 17, and 19 mmHg, respectively), but not the QTL on chromosome 4. Thus these four QTLs affected BP phenotypes differently: 1) in the presence of high salt intake (chromosome 16), 2) only associated with normal salt intake (chromosome 4), and 3) regardless of salt intake (chromosome 2c and 2a). Moreover, salt sensitivity was abrogated in congenics SHR.BN2a and SHR.BN16. Finally, we provide evidence for the influence of genetic background on the expression of the mapped QTLs individually or as a group. Collectively, these data reveal previously unsuspected nuances of the physiological roles of each of the four mapped BP QTLs in the SHR under basal and/or salt loading conditions unforeseen by the analysis of the F2 cross.
PubMed ID
19126752 View in PubMed
Less detail

Contrast-enhanced MRI with gadodiamide injection in rat disease models.

https://arctichealth.org/en/permalink/ahliterature22688
Source
J Vet Med Sci. 1996 Apr;58(4):291-5
Publication Type
Article
Date
Apr-1996
Author
K. Yamada
K. Miyahara
H. Sato
W. Nakayama
M. Sato
T. Hirose
H. Kato
H. Ikehira
Y. Tateno
H. Sugihara
K. Furuhama
Author Affiliation
Department of Veterinary Clinical Radiology, Obihiro University of Agriculture and Veterinary Medicine, Japan.
Source
J Vet Med Sci. 1996 Apr;58(4):291-5
Date
Apr-1996
Language
English
Publication Type
Article
Keywords
Animals
Arterial Occlusive Diseases - diagnosis - pathology
Carcinogens
Cerebral Arterial Diseases - diagnosis - pathology
Cerebrovascular Disorders - diagnosis - pathology
Contrast Media
Diethylnitrosamine
Gadolinium - administration & dosage - diagnostic use
Gadolinium DTPA
Hydronephrosis - diagnosis - pathology
Injections, Intravenous
Liver Neoplasms, Experimental - chemically induced - diagnosis - pathology
Magnetic Resonance Imaging - methods - veterinary
Male
Organometallic Compounds - administration & dosage - diagnostic use
Pentetic Acid - administration & dosage - analogs & derivatives - diagnostic use
Rats
Rats, Inbred F344
Rats, Inbred SHR
Rats, Sprague-Dawley
Abstract
The present study was designed to confirm the usefulness of contrast-enhanced magnetic resonance imaging (MRI) in diagnosing strokes of stroke-prone spontaneously hypertensive rats (SHRSP) and middle cerebral artery (MCA) occlusion, hepatocellular carcinoma and hydronephrosis of each experimental rat model. Male Sprague-Dawley rats (250-500 g), male SHRSP (ca. 250 g) and male F344 rats (ca. 300 g) were used for the investigation. Gadodiamide injection (Omniscan, Daiichi Pharmaceutical Co., Ltd. and Nycomed AS, Norway) was administered intravenously as the contrast agent at a dose of 0.1 mmol/kg except in hydronephrosis, where a dose of 0.05 mmol/kg was used. Magnetic resonance (MR) images were obtained with a 1.5T or a 2.0T magnetic field strength MRI unit. The signal intensity of the stroke lesions was increased after administration of gadodiamide injection in SHRSP and MCA-occluded rats. Hepatocellular carcinoma was undetectable without the use of the contrast agent, but the signal intensity of the tumor increased after administration of the gadodiamide injection, allowing the lesions to be detected. The signal intensity of the renal medulla increased in the non-ligated kidney, but not in the hydronephrotic kidney. The information given by the post-contrast images were superior to those obtained from the pre-contrast images in all the models. Contrast effects in SHRSP and MCA-occluded rats were related to differences in capillary permeability, those in rats with hepatocellular carcinoma depended on differences in vascularity, and those in hydronephrotic rats depended on blood flow and permeability.
PubMed ID
8741259 View in PubMed
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Differential regulation of cardiac adrenomedullin and natriuretic peptide gene expression by AT1 receptor antagonism and ACE inhibition in normotensive and hypertensive rats.

https://arctichealth.org/en/permalink/ahliterature54153
Source
J Hypertens. 1999 Nov;17(11):1543-52
Publication Type
Article
Date
Nov-1999
Author
J. Magga
J. Kalliovalkama
H. Romppanen
O. Vuolteenaho
I. Pörsti
M. Kähönen
J P Tolvanen
H. Ruskoaho
Author Affiliation
Department of Pharmacology and Toxicology, University of Oulu, Finland.
Source
J Hypertens. 1999 Nov;17(11):1543-52
Date
Nov-1999
Language
English
Publication Type
Article
Keywords
Angiotensin-Converting Enzyme Inhibitors - pharmacology
Animals
Atrial Natriuretic Factor - genetics
Blood Pressure - drug effects
Cardiomegaly - pathology
Enalapril - pharmacology
Gene Expression - drug effects
Heart - physiopathology
Hypertension - genetics - physiopathology
Losartan - pharmacology
Male
Natriuretic Peptide, Brain
Peptides - genetics
Rats
Rats, Inbred SHR
Rats, Inbred WKY
Receptor, Angiotensin, Type 1
Receptor, Angiotensin, Type 2
Receptors, Angiotensin - antagonists & inhibitors
Reference Values
Research Support, Non-U.S. Gov't
Abstract
OBJECTIVE: To study the effects of long-term treatment with the type 1 angiotensin (AT1) receptor antagonist losartan and the angiotensin-converting enzyme (ACE) inhibitor enalapril, on cardiac adrenomedullin (ADM), atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) gene expression. METHODS: Spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats were given losartan (15 mg/kg per day) or enalapril (4 mg/kg per day) orally for 10 weeks. The effects of drugs on systolic blood pressure, cardiac hypertrophy, ANP, BNP and ADM mRNA and immunoreactive-ANP (IR)-ANP, IR-BNP and IR-ADM levels in the left ventricle and atria were compared. RESULTS: Losartan and enalapril treatments completely inhibited the increase of systolic blood pressure occurring with ageing in SHR. The ratio of heart to body weight was reduced in both losartan- and enalapril-treated SHR and WKY rats. Treatment with losartan or enalapril reduced left ventricular ANP mRNA and IR-ANP in both strains, and ventricular BNP mRNA levels in SHR rats. Inhibition of ACE, AT1 receptor antagonism, changes in blood pressure or cardiac mass had no effect on left ventricular ADM gene expression in SHR and WKY rats. In addition, atrial IR-ANP and IR-ADM levels increased in SHR whereas IR-BNP levels decreased in WKY and SHR rats in response to drug treatments. CONCLUSIONS: Our results show that ventricular ADM synthesis is an insensitive marker of changes in haemodynamic load or cardiac hypertrophy. Furthermore, the expression of ADM, ANP and BNP genes is differently regulated both in the left ventricle and atria in response to AT1 receptor antagonism and ACE inhibition.
PubMed ID
10608466 View in PubMed
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Distinct upregulation of extracellular matrix genes in transition from hypertrophy to hypertensive heart failure.

https://arctichealth.org/en/permalink/ahliterature53166
Source
Hypertension. 2005 May;45(5):927-33
Publication Type
Article
Date
May-2005
Author
Jaana Rysä
Hanna Leskinen
Mika Ilves
Heikki Ruskoaho
Author Affiliation
Department of Pharmacology and Toxicology, Biocenter Oulu, University of Oulu, Oulu, Finland.
Source
Hypertension. 2005 May;45(5):927-33
Date
May-2005
Language
English
Publication Type
Article
Keywords
Animals
Blood pressure
Cardiac Output, Low - etiology - genetics - metabolism
Echocardiography
Extracellular Matrix - metabolism
Gene Expression
Hypertension - complications - metabolism - physiopathology
Hypertrophy, Left Ventricular - etiology - genetics - metabolism - ultrasonography
Male
Oligonucleotide Array Sequence Analysis
Rats
Rats, Inbred SHR
Rats, Inbred WKY
Research Support, Non-U.S. Gov't
Up-Regulation
Abstract
Cardiac hypertrophy in response to pressure overload is initially beneficial but eventually leads to heart failure, a major cause of morbidity and mortality in the Western countries. Although abnormalities in left ventricular (LV) diastolic filling are early features associated with pressure overload-induced LV hypertrophy, the molecular mechanisms regulating transition to diastolic heart failure are poorly understood. We analyzed global changes in gene expression in 12-, 16-, and 20-month-old spontaneously hypertensive rats (SHR) and their age-matched controls, Wistar Kyoto rats, using DNA microarrays. In SHR, a progressive LV hypertrophy was associated with increased expression of hypertrophy-associated genes including contractile protein and natriuretic peptide genes. Echocardiography indicated that 16-month-old SHR had features of diastolic dysfunction leading to diastolic failure at age 20 months without significant changes in LV systolic function. Comparison analysis revealed that the extracellular matrix genes strikingly dominated the list of altered genes after transition to the heart failure, whereas there was no major shift in gene expression patterns involved in calcium homeostasis and neurohumoral activation, as well as myofilament contractile and cytoskeletal proteins. The microarray analysis also revealed differential gene expression of several novel factors, such as thrombospondin-4 and matrix Gla protein, as well as unknown expressed sequence tags. Our data show that transition from LV hypertrophy to diastolic hypertensive heart failure is almost exclusively associated with progressive remodeling of the extracellular matrix and provide new insights into the pathogenesis of hypertrophy by suggesting existence of novel regulators of LV remodeling.
PubMed ID
15837839 View in PubMed
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47 records – page 1 of 5.