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At least 307 records · Page 17Linked to original sources
PubMed1998

Monkey leptin receptor mRNA: sequence, tissue distribution, and mRNA expression in the adipose tissue of normal, hyperinsulinemic, and type 2 diabetic rhesus monkeys.

OBJECTIVE: We have cloned the rhesus monkey leptin receptor and examined its mRNA expression levels in the adipose tissue of monkeys to investigate the regulation of gene expression of the leptin receptor. RESEARCH METHODS AND PROCEDURES: Monkey leptin receptor cDNA was cloned by reverse transcriptase-polymerase chain reaction (RT-PCR). Tissue distribution of monkey leptin receptor was examined by Northern blot analysis and RT-PCR. The mRNA levels of monkey leptin receptor in adipose tissue of normal (n=10), hyperinsulinemic obese (n=8), and type 2 diabetic monkeys (n=8) were measured by quantitative RT-PCR. RESULTS: Monkey leptin receptor cDNA had at least two alternatively spliced isoforms (long and short forms). The long form of the leptin receptor mRNA was expressed relatively highly in liver, adipose tissue, hypothalamus, and choroid plexus, whereas the total leptin receptors were expressed in every tissue examined. The mRNA levels of the long form of the leptin receptor in adipose tissue were not correlated to body weight, fasting plasma insulin, plasma glucose, or plasma leptin levels. The mRNA levels of the long form of the leptin receptor were highly correlated to that of the total leptin receptor (long and short form). DISCUSSION: The long form of leptin receptor mRNA existed in adipose tissue as well as in liver and hypothalamus, suggesting that the leptin receptor in adipose tissue may be functional in adipose tissue. The expression of the leptin receptor mRNA in adipose tissue is not affected by obesity, hyperinsulinemia, or diabetes.

Adipose Tissue↗
PubMed2001

Isolation of Escherichia coli mRNA and comparison of expression using mRNA and total RNA on DNA microarrays.

Bacterial messenger RNA (mRNA) is not coherently polyadenylated, whereas mRNA of Eukarya can be separated from stable RNAs by virtue of polyadenylated 3'-termini. We have developed a method to isolate Escherichia coli mRNA by polyadenylating it in crude cell extracts with E. coli poly(A) polymerase I and purifying it by oligo(dT) chromatography. Differences in lacZRNA levels were similar with purified mRNA and total RNA in dot blot hydridizations for cultures grown with or without gratuitous induction of the lactose operon. More broadly, changes in gene expression upon induction were similar when cDNAs primed from mRNA or total RNA with random hexanucleotides were hydridized to DNA microarrays for the E. coli genome. Comparable signal intensities were obtained with only 1% as much oligo(dT)-purified mRNA as total RNA, and hence in vitro poly(A) tailing appears to be selective for mRNA. These and additional studies of genome-wide expression with DNA microarrays provide evidence that in vitro poly(A) tailing works universally for E. coli mRNAs.

Cell Extracts↗
PubMed1999

Endometrial ISG17 mRNA and a related mRNA are induced by interferon-tau and localized to glandular epithelial and stromal cells from pregnant cows.

The interferon stimulated gene product, ISG17, conjugates to bovine uterine proteins in response to conceptus-derived interferon (IFN)-tau. The objectives of the present experiments were to examine induction of ISG17 (0.65 kb) and a related 2.5 kb mRNA in response to IFN-tau and pregnancy using Northern blotting procedures, and to determine cell types in the endometrium that expressed ISG17 mRNA using in situ hybridization. RNA was isolated from endometrial explants or from bovine endometrial (BEND) cells cultured in the absence (control) or presence of 25 nM recombinant (r) bolFN-tau for 0, 3, 6, 12, 24, or 48 h. The major ISG17 0.65 kb mRNA and a minor 2.5 kb mRNA were induced (p<0.05) after 6 h (explants) or 3 h (BEND cells) treatment with rboIFN-tau. Both mRNAs were present in endometrium from day 18 pregnant cows, but were absent in endometrium from nonpregnant cows. The ISG17 mRNA was localized to stromal and glandular epithelial cells on d 18 of pregnancy. The 2.5 kb mRNA may encode a novel ISG17 homolog, or a unique polyISG17 repeat that is similar in structure to the polyubiquitin genes. Because ISG17 mRNA is induced in stromal and glandular epithelial cells, it could be assumed that ISG17 has a role in regulating intracellular proteins in both cell types.

Animals↗
PubMed2005

Effect of exercise on the expression of adiponectin mRNA and GLUT4 mRNA in type 2 diabetic rats.

To investigate the impact of exercise on the expression of adiponectin and GLUT4 mRNA in type 2 diabetic rats, type 2 diabetic rat model was made. The diabetic rats were treated with swimming training for 8 weeks. The expression of adiponectin mRNA in perirenal fat and GLUT4 mRNA in skeletal muscles were assessed by reverse transcription polymerase chain reaction (RT-PCR) and the levels of blood glucose, serum insulin, and blood lipid were measured. Our results showed that the expression of adiponectin mRNA and GLUT4 mRNA in diabetic model group was decreased by 45% (P < 0.01), 43% (P < 0.01) respectively. The gene expression of adiponectin and GLUT4 was increased significantly in swimming group (P < 0.05 and P < 0.01, respectively). Compared with the model group, fasting insulin, TG, TC and FFA were decreased significantly in the training group (P < 0.05 or P < 0.01) as compared with model group. It is concluded that exercise can promote the expression of adiponectin mRNA and GLUT4 mRNA in type 2 diabetic rats, which may be one of the mechanisms responsible for the amelioration of insulin resistance in the rats.

Adiponectin↗
PubMed2005

A new splicing acceptor site and poly(A)+ sequence signal within DQA1*0401 and DQA1*0501 mRNA 3'UTR contribute to increase the extraordinary diversity of mRNA isoforms.

In this paper, we have analysed the diversity of mRNA species generated by DQA1*0501 and DQA1*0401 alleles in homozygous B-lymphoblastoid cell lines. As we previously reported, six mRNA isoforms that differ in the 3'UTR have been identified in these cells. This diversity of mRNA species results both from the alternative use of two acceptor spliced sites and the differential selection of two poly(A)+ sequence signals by the processing machinery. In this report we describe a new acceptor sequence signal that allows generation of a new alternative spliced mRNA species. This acceptor sequence signal was also present in all of the seven DQA1 homozygous cell lines analysed. In addition, we have identified a previously undetected, non-conventional but functional, poly(A)+ sequence signal that lacks an identifiable AATAAA hexamer, one of the most important element of the core. This sequence signal allows the generation of two additional mRNA isoforms both in DQA1*0501 and DQA1*0401 homozygous cell lines but not in the others. We show that DQA1*0501 and DQA1*0401 primary transcripts can be processed into nine mRNA isoforms that differ in the 3'UTR. Finally, we summarized all the DQA1 mRNA species deriving from DQA1*0101, DQA1*0102, DQA1*0103, DQA1*0201, DQA1*0301, DQA1*0401 and DQA1*0501 alleles and shown in B-lymphoblastoid cell lines.

3' Untranslated Regions↗
PubMed1993

Intracerebroventricular administration of corticotropin-releasing factor induces c-fos mRNA expression in brain regions related to stress responses: comparison with pattern of c-fos mRNA induction after stress.

Centrally administered corticotropin-releasing factor (CRF) produces a number of physiological and behavioral changes akin to those elicited by exposure to acute stress. However, the specific brain site of action responsible for the centrally activating property of CRF has not been precisely determined. In this study, we used in situ hybridization histochemistry for c-fos mRNA to map potential neuronal structures activated after intracerebroventricular (i.c.v.) injection of CRF and compared the distribution of c-fos mRNA with that after stress. Wistar male rats were sacrificed 30, 60, 120 and 180 min after the i.c.v. injection of 1 microgram ovine CRF or vehicle alone. Another group of rats was exposed to immobilization stress for 60 min or electrical foot-shock stress (1.5 mA, 1-s duration, 30 x) for 15 min and sacrificed before and 30, 60, 120 and 180 min after the beginning of stress. Centrally administered CRF rapidly (30-60 min) induced c-fos mRNA expression in most of the areas that showed hybridization signals for c-fos after stress: the limbic structures, including the piriform cortex, cingulate cortex, the lateral septal nucleus, the hippocampus, the anterior corticomedial and the medial amygdaloid nuclei, the hypothalamic nuclei, such as the paraventricular nucleus, the supraoptic nucleus (SO) and the dorsomedial nucleus (DMD), and some brainstem nuclei like the pontine nucleus, the locus ceruleus (LC) and Barrington's nucleus. The granular layer of the cerebellum, some thalamic nuclei and the habenula also showed hybridization signals after i.c.v. injection of CRF and stress. However, c-fos induction in the bed nucleus of the stria terminalis, the central nucleus of the amygdala (CeA) and the nucleus tractus solitarius (SOL) was seen only after i.c.v. administration of CRF; in the septo-hypothalamic nucleus and the superior olive, however, c-fos mRNA expression was observed only after stress. There were no differences in the pattern of c-fos mRNA expression between the two stress paradigms. In contrast, i.c.v. injection of saline-induced expression of c-fos mRNA in the piriform cortex, neocortex, cingulate cortex and the amygdala was much less than that seen after i.c.v.-administered CRF as evident in the intensity of the signals. These results suggest that CRF produces c-fos mRNA expression in the brain areas related to stress response, and that CRF may induce behavioral and neuroendocrine responses through activating these brain structures, such as the limbic system and the hypothalamic nuclei.(ABSTRACT TRUNCATED AT 400 WORDS)

Analysis of Variance↗
PubMed1989

Mechanism of interferon action. Activation of the human P1/eIF-2 alpha protein kinase by individual reovirus s-class mRNAs: s1 mRNA is a potent activator relative to s4 mRNA.

The ability of pure viral and cellular single-strand (ss) RNAs to activate the interferon-induced, double-stranded (ds) RNA-dependent P1/eIF-2 protein kinase purified from human amnion U cells was examined. In addition to the well-established activation of P1 kinase autophosphorylation in vitro by reovirus genome dsRNA, the P1 kinase was also efficiently activated by certain reovirus ssRNAs. The reovirus s1 mRNA was a potent activator of the kinase. By contrast, the reovirus s4 mRNA was a poor activator of the kinase. Likewise, adenovirus VAI RNA, transfer RNA, 5 S ribosomal RNA, and rabbit globin mRNA were not activators or were very poor activators of the purified P1/eIF-2 protein kinase. Analysis of hybrid ssRNAs produced between the reovirus s1 and s4 mRNAs revealed that both the 5' and the 3' portions of the s1 mRNA possessed nucleotide sequences capable of mediating kinase activation. Subsequent deletion analysis of the 5' portion of the s1 mRNA identified a 161-nucleotide region located between positions 416 and 576 which was sufficient for P1 kinase activation. Treatment of reovirus s1 mRNA transcripts with either ssRNA- or dsRNA-specific ribonucleases, but not with heat, destroyed the ability of s1 mRNA transcripts to activate the kinase. These results suggest that P1 kinase autophosphorylation in vitro may be selectively activated by individual ssRNAs in a differential manner, and that a secondary or higher-ordered ssRNA structure(s) may be important in mediating the activation.

DNA Mutational Analysis↗
PubMed1992

Neural cell adhesion molecule (NCAM) and N-cadherin mRNA during development and aging: selective reduction in the 7.4-kb and 6.7-kb NCAM mRNA levels in the hippocampus of adult and old rats.

By examining the time course, from E15 to 720 days of age, for changes in the prevalence of mRNAs coding for neural cell adhesion molecule (NCAM), N-cadherin and alpha-tubulin in rat hippocampus and forebrain, it was concluded that (i) the NCAM 7.4-, 6.7-, 5.2-, 4.3- and 2.9-kb mRNAs are differentially regulated during development and aging; (ii) the 7.4- and 6.7-kb mRNA are drastically reduced starting from day 21 onward; (iii) the E15- and day-1-specific mRNA of 4.3 kb is replaced with the 5.2-kb mRNA starting with 21 days, thereafter the 5.2-kb message remained relatively constant over the entire life-span studied. Likewise, the 2.9-kb mRNA, which was very abundantly expressed at E15 and early postnatal stages, remained relatively constant between 180 days and 720 days; (iv) postnatal rat brains showed both qualitative and quantitative changes in N-cadherin 4.3- and 4.0-kb transcripts. The 4.3-kb mRNA was relatively abundant at 1 and 21 days postnatal stages, thereafter the signal remained very low over the entire life-span studied. The 4.0-kb message, which was specific for the E15 stage, was replaced with the 4.3-kb message; (v) as expected, the 1.8-kb mRNA coding for embryonic alpha-tubulin decreased dramatically after 1 day, but became stabilized at moderate levels during the subsequent developmental stages. At least for the NCAM gene, the regulation seems to occur post-transcriptionally, possibly at the level of RNA processing while the N-cadherin mRNA expression seems to be transcriptionally regulated.

Aging↗
PubMed1981

Unstable beta-globin mRNA in mRNA-deficient beta o thalassemia.

The molecular defect in four Kurdish Jews with homozygous, mRNA-deficient beta zero thalassemia was investigated. Electrophoretic profiles of pulse-labeled alpha- and beta-globin RNAs are similar to those of non-thalassemics; therefore, at least one of the thalassemic beta-globin alleles is transcribed. During a 30 min actinomycin D chase, most of the alpha- and beta-globin mRNA precursors and processing intermediates are converted to mRNA-sized RNA. Thalassemic and non-thalassemic beta-globin RNAs are indistinguishable, as determined by S1 nuclease mapping and RNA blotting. Non-thalassemic beta-globin mRNA is stable during a 30 min actinomycin chase, but 30%-75% of the thalassemic mRNA-sized molecules is degraded during that period. We conclude that the absence of beta-globin mRNA in this disease results from rapid turnover of beta-globin mRNA-sized molecules.

Adolescent↗
PubMed1991

Astrocytic apolipoprotein E mRNA and GFAP mRNA in hippocampus after entorhinal cortex lesioning.

Entorhinal cortex lesions (ECL) that damage the perforant path to the hippocampus induce rapid increases of apolipoprotein E (apo E) mRNA in the hippocampus. Apo E mRNA was localized in astrocytes by in situ hybridization in combination with immunocytochemistry for glial fibrillary acidic protein (GFAP). Unilateral ECL also increased hippocampal GFAP mRNA, with increases preceding those of apo E mRNA. The apo E mRNA and GFAP mRNA responses were transiently bilateral in non-denervated zones. The timing of response in apo E mRNA to deafferentation supports suggestions that apo E has roles in membrane remodelling during responses to neuron injury.

Animals↗
PubMed1993

Decreased tyrosine hydroxylase mRNA but not cholecystokinin mRNA in the pars compacta of the substantia nigra and ventral tegmental area of aged rats.

Quantitative in situ hybridization histochemistry was used to determine the age-related changes in tyrosine hydroxylase (TH) mRNA and cholecystokinin (CCK) mRNA in the ventral tegmental area (VTA) and substantia nigra pars compacta (SNc) of the rat. Coronal sections (10 microns) were cut in a cryostat through the VTA and SNc of brains from 3 months and 33 month old Sprague-Dawley rats and immediately adjacent sections hybridized with 35S-labelled 45-mer oligonucleotide probes specific for either the rat TH or CCK genes. The mRNA levels of each gene were estimated by computerised densitometric analysis of the signal on X-ray film autoradiograms and estimation of the number of mRNA expressing cells as well as the density of expression per cell (grain density) was made from high resolution emulsion autoradiograms. Analysis of the TH mRNA on X-ray film autoradiograms indicated that the levels averaged 25% lower in the SNc (P < 0.01) and 18% lower in the VTA (P < 0.05) of the old rats. However, analysis of the emulsion autoradiograms showed that this reduction in TH mRNA in the VTA and SNc in the old rats was not due to a loss of TH mRNA expressing cells but due to a reduction in the hybridization signal per expressing cell.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1994

A single administration of ethanol simultaneously increases c-fos mRNA and reduces c-jun mRNA in the hypothalamus and hippocampus.

We have previously demonstrated that a single administration of ethanol induces the expression of c-fos mRNA in the hypothalamic paraventricular nucleus (PVN). However, Fos protein must interact with a member of the Jun family to form functional heterodimers. To determine whether ethanol may have differential effects on c-fos and c-jun expression, we injected male rats acclimated to a 25 degrees C environment with ethanol (3 g/kg b.wt.) or saline. Using in situ hybridization histochemistry with oligonucleotide probes, we found that ethanol increased c-fos mRNA in the PVN, but decreased c-jun mRNA both in the PVN and in hippocampus. Considering that ethanol produces hypothermia and that the PVN contains neurons activated during hypothermia, we evaluated the effect of cold on c-fos and c-jun mRNA. Both cold and ethanol increased c-fos mRNA, and the effects were additive. However, c-jun mRNA levels in both PVN and hippocampus were unaffected by temperature. Finally, c-jun mRNA levels in the hippocampus were significantly reduced by chronic ethanol exposure, and this trend was also observed in the PVN. These findings demonstrate that a single injection of ethanol has opposite effects on the expression of nuclear transcription factors which interact to regulate gene expression in the nervous system.

Alcoholism↗
PubMed1989

Developmental expression of proenkephalin A mRNA and phenylethanolamine N-methyltransferase mRNA in foetal sheep adrenal medulla.

The ontogenic expression of proenkephalin A (ProEnk A) mRNA and phenylethanolamine N-methyltransferase (PNMT) mRNA was examined in the foetal sheep adrenal medulla by the use of specific oligodeoxyribonucleotide probes. Northern blot analysis of RNA extracts from foetal adrenals demonstrated that ProEnk A mRNA was expressed as early as 60 days of gestation, a time at which the foetal adrenal is not functionally innervated. In situ hybridization on sections of foetal adrenals revealed that at 110-140 days gestation ProEnk A mRNA was expressed in chromaffin cells at the outer margin of the adrenal medulla but at earlier stages of gestation (e.g. 95 days) appeared to be expressed homogeneously throughout the whole of the adrenal medulla. In comparison, PNMT mRNA was expressed preferentially in cells at the outer margin of the adrenal medulla from the earliest stage detectable. Both PNMT mRNA and ProEnk A mRNA co-localized in cells at the outer margin of foetal adrenal of late gestations (110-140 days), a similar pattern to that seen in the adult adrenal medulla. These results indicate that, as with adult animals, in foetuses of late gestation, adrenal enkephalins are co-stored within adrenaline cells. It is likely therefore that enkephalins are co-released from the foetal adrenal with adrenaline in response to intra-uterine stress.

Adrenal Medulla↗
PubMed2005

mRNA transfection of dendritic cells: synergistic effect of ARCA mRNA capping with Poly(A) chains in cis and in trans for a high protein expression level.

The occurrence of translation mechanism in the cytosol offers advantages to mRNA transfer over DNA-based transfection in non-dividing cells. Here, we sought to optimize mRNA constructs allowing a high level of protein upon lipofection. We found that luciferase into mouse dendritic cells (JAWSII cells) was approximately 20-fold higher when the luciferase mRNA was capped with 3'-O-methyl-m7(5')Gppp5'G (anti-reverse cap analogue; ARCA) than with m7(5')Gppp5'G (CAP). Adding a Poly(A) tail of 100 instead of 64 adenosines in cis increased by approximately 35-fold more the protein level. Finally, ARCA-Luc-mRNA-A100 construct was 700-fold better efficient than the CAP-Luc-mRNA-A64 one. Moreover, co-transfection with free Poly(A) chains in trans enhanced by 100% the luciferase level. The efficiency of ARCA-mRNA-A100 construct was validated in immature and mature human CD34-derived dendritic cells. Such mRNA construct was also successful to obtain high level of MART-1 tumor antigen.

Animals↗
PubMed2005

Decreased relative expression level of trefoil factor 3 mRNA to galectin-3 mRNA distinguishes thyroid follicular carcinoma from adenoma.

The expression level of trefoil factor 3 (TFF3) mRNA is a marker for distinguishing thyroid follicular adenomas from carcinomas. However, when measuring the expression level of TFF3 mRNA in fine needle aspiration biopsies, an appropriate internal control mRNA, of which expression is restricted in thyroid epithelial--derived cells, is necessary, since they are often contaminated with a considerable number of blood cells, which do not express TFF3 mRNA. In this study, we evaluated the efficiency of molecular-based diagnosis of thyroid follicular carcinoma by measuring the relative expression of TFF3 mRNA by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) using galectin-3 mRNA as an internal control. The TFF3/galectin-3 mRNA ratio (T/G ratio) was measured in 54 follicular adenomas and 29 follicular carcinomas. It was markedly decreased in 7 follicular carcinomas of widely invasive type and with evident distant metastases. When the cutoff point was set at 16.0 by a receiver operator characteristic curve, the TG ratio showed good agreement with the pathological diagnosis [kappa=0.55; 95% confidence interval (CI), 0.34-0.77]. This agreement was better when the pathologically questionable cases were excluded (kappa=0.72; 95% CI, 0.49-0.95). Quantification of the T/G ratio may be a useful tool for the distinction between follicular adenomas and carcinomas, which is the most difficult in thyroid pathology.

Adenocarcinoma, Follicular↗
PubMed2005

Transcript copy number of genes for DNA repair and translesion synthesis in yeast: contribution of transcription rate and mRNA stability to the steady-state level of each mRNA along with growth in glucose-fermentative medium.

We quantitated the copy number of mRNAs (NTG1, NTG2, OGG1, APN1, APN2, MSH2, MSH6, REV3, RAD30) encoding different DNA repair enzymes and translesion-synthesis polymerases in yeast. Quantitations reported examine how the steady-state number of each transcript is modulated in association with the growth in glucose-fermentative medium, and evaluate the respective contribution of the rate of mRNA degradation and transcription initiation to the specific mRNA level profile of each gene. Each transcript displayed a unique growth-related profile, therefore altering the relative abundance of mRNAs coding for proteins with similar functions, as cells proceed from exponential to stationary phase. Nonetheless, as general trend, they exhibited maximal levels when cells proliferate rapidly and minimal values when cells cease proliferation. We found that previous calculations on the stability of the investigated mRNAs might be biased, in particular regarding those that respond to heat shock stress. Overall, the mRNAs experienced drastic increments in their stabilities in response to gradual depletion of essential nutrients in the culture. However, differences among the mRNA stability profiles suggest a dynamic modulation rather than a passive process. As general rule, the investigated genes were much more frequently transcribed during the fermentative growth than later during the diauxic arrest and the stationary phase, this finding conciliating low steady-state levels with increased mRNA stabilities. Interestingly, while the rate at which each gene is transcribed appeared as the only determinant of the number of mRNA copies at the exponential growth, later, when cell growth is arrested, the rate of mRNA degradation becomes also a key factor for gene expression. In short, our results raise the question of how important the respective contribution of transcription and mRNA stability mechanisms is for the steady-state profile of a given transcript, and how this contribution may change in response to nutrient-availability.

Cell Division↗
PubMed2003

Digoxin up-regulates multidrug resistance transporter (MDR1) mRNA and simultaneously down-regulates steroid xenobiotic receptor mRNA.

A steroid xenobiotic receptor (SXR) is involved in the induction of MDR1/P-glycoprotein. MDR1 up-regulation by digoxin was previously demonstrated in human colon adenocarcinoma Caco-2 cells, but the participation of SXR remains unclear. Herein, the participation of SXR in MDR1 up-regulation was examined using reverse transcription-polymerase chain reaction in Caco-2 cells, and digoxin-tolerant cells (Caco/DX) as well as human colon carcinoma LS180 cells, which expressed SXR. MDR1 mRNA expression in Caco-2 or LS180 cells was increased by exposure to 1 microM digoxin for 24h, in a concentration-dependent manner, but SXR mRNA decreased concentration-dependently and was undetectable or significantly lower at 1 microM digoxin, indicating antithetical changes in MDR1 and SXR mRNA expression. Moreover, the MDR1 mRNA level was higher in Caco/DX cells than Caco-2 cells, whereas the SXR mRNA level was lower in Caco/DX cells. Consequently, digoxin was demonstrated to up-regulate MDR1 mRNA and simultaneously down-regulate SXR mRNA expression.

Adenocarcinoma↗
PubMed1998

Pulmonary and cardiac expression of preproendothelin-1 mRNA are increased in heart failure after myocardial infarction in rats. Localization of preproendothelin-1 mRNA and endothelin peptide.

OBJECTIVES: Recent reports indicate that endothelin (ET) plays an important pathophysiological role in congestive heart failure (CHF). However, existing data on local cardiopulmonary ET production are few. No studies have hitherto examined the specific anatomic localization of cardiopulmonary ET synthesis in CHF. Thus, the aims of the present study were to examine whether cardiopulmonary preproET-1 mRNA synthesis is upregulated in CHF and to determine the anatomic localization of preproET-1 mRNA and the mature peptide. METHODS: CHF was induced in rats by occluding the left coronary artery. Only animals with a left ventricular end-diastolic pressure above 15 mmHg after one week were included (n = 28). Sham-operated animals served as controls (n = 24). Hearts and lungs were examined by mRNA slot blot analyses, in situ hybridization (ISH) and immunohistochemistry (IHC). RESULTS: In CHF-rats, slot blot analyses revealed a 3.5 +/- 1.1-fold and a 6.4 +/- 0.8-fold upregulation of preproET-1 mRNA in the noninfarcted and the infarcted area of the left ventricles, respectively (p < 0.05 for both). ISH revealed that the preproET-1 mRNA was localized predominantly over the granulation tissue in the infarcted region. The ET peptide was predominantly localized to inflammatory cells and remaining cardiomyocytes in the infarcted region as determined by IHC. Lungs from CHF-rats showed a 1.5 +/- 0.1-fold upregulation of preproET-1 mRNA (p = 0.01). The most abundant preproET-1 mRNA and ET-1-like-immunoreactivity (ET-1-ir) was seen over inflammatory cells and over airway epithelial cells. Some ET-1-ir was also located to bronchial and vascular smooth muscle cells. CONCLUSION: Increased cardiopulmonary ET synthesis strongly suggest a pathophysiological role for ET in CHF.

Animals↗