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H Seo

Publications and source records attributed to H Seo.

At least 73 records · Page 4Linked to original sources

Culture in vector-averaged gravity environment in a clinostat results in detachment of osteoblastic ROS 17/2.8 cells.

Studies carried out in space flights and in altered gravitational environments have shown that exposure to altered gravity conditions results in alterations in cellular structure and function. In the present study, we used a clinostat to generate a vector-averaged gravity environment, and evaluated the responses of osteoblast-like ROS 17/2.8 cells subsequent to rotation at 50 r.p.m from 24 to 72 hr. We found that the cells started to detach during the first 24 hr of culture in clinostat, but not in stationary and horizontal rotation (the latter serving as a control for turbulence, shear forces and vibrations). At 24 hr, there was a significant decrease in the number of adherent cells under clino-rotation (2.75 +/- 0.5 x 10(5) in stationary culture versus 2.02 +/- 0.27 x 10(5) under clino-rotation), and 19.8% of adherent cells were trypan-blue positive when cultured in 2% fetal bovine serum. All the detached cells were trypan-blue positive. At 72 hr, the cells became confluent in all three groups. These results suggest that vector-averaged gravity could cause the death of osteoblasts during the first 24 hr of clino-rotation. We hypothesize that this cell death might play a role in the pathogenesis of osteoporotic bone loss as observed in actual space flight.

Animals↗

Effects of vector-averaged gravity on NF-kappa B activation in human osteoblast-like cells.

We have recently demonstrated that a transcription factor, nuclear factor kappa B (NF-kappa B), plays a key role in the production of cytokine and cell adhesion molecules in osteoblastic cells. In the present study, we investigated the effects of vector-averaged gravity (clinostat rotation) on tumor necrosis factor (TNF)-alpha-induced activation of NF-kappa B in human osteoblastic HOS-TE85 cells. After a 72-hr clinostat culture, the cells were treated with TNF-alpha for 30 min. Electrophoretic mobility shift assay using the nuclear extracts revealed that the DNA-binding activity of NF-kappa B was substantially reduced in clinostat-cultured cells compared with the stationary control. Concomitantly, the transactivation of NF-kappa B was examined by a transfection study. The cells were transfected with a plasmid expressing a luciferase reporter gene driven by multimerized NF-kappa B sites. They were cultured in the clinostat for 48-hr, followed by a 4-hr treatment with TNF-alpha. Clinostat culture resulted in a significant decrease in the luciferase activities, being consistent with the decreased binding of NF-kappa B. These results indicate that exposure of HOS-TE85 cells to vector-averaged gravity impairs NF-kappa B activation by TNF-alpha.

DNA↗

Intracellular proteolytic cleavage of 9-cis-retinoic acid receptor alpha by cathepsin L-type protease is a potential mechanism for modulating thyroid hormone action.

We previously reported that the responsiveness of hepatocytes to thyroid hormone is markedly attenuated when they were cultured as monolayers rather than spheroids. To elucidate the mechanisms underlying the altered responsiveness, thyroid hormone receptor auxiliary proteins in the hepatocytes were analyzed by electrophoretic mobility shift assay. The major thyroid hormone receptor auxiliary protein was identified as 9-cis-retinoic acid receptor alpha (RXRalpha) in the hepatocytes regardless of the culture conditions. The cytoplasmic fraction was shown to contain a protease(s) that cleaves RXRalpha at its amino terminus. The presence of the protease in the cytosol, but not in the nucleus, was ascertained by incubating full-length 35S-labeled RXRalpha with each fraction. Using various protease inhibitors, it was shown that cathepsin L-type protease could participate in the cleavage of the RXRalpha. The enzyme activity was much higher in the monolayers than the spheroids. Inhibition of this enzyme activity in the monolayer hepatocyte resulted in the increase of nuclear RXRalpha protein and the augmentation of T3-dependent induction of spot 14 mRNA. These results suggest that the changes in cathepsin L-type protease activity in the cytosol may alter the turnover of RXRalpha in the nucleus and modify the function of steroid receptor superfamilies that heterodimerize with RXRalpha.

Animals↗

Noradrenergic-specific transcription of the dopamine beta-hydroxylase gene requires synergy of multiple cis-acting elements including at least two Phox2a-binding sites.

Dopamine beta-hydroxylase (DBH) catalyzes the conversion of dopamine to noradrenaline and is selectively expressed in noradrenergic and adrenergic neurons and neuroendocrine cells. Recent data from this laboratory showed that a paired-like homeodomain (HD) protein, Phox2a, interacts with the HD-binding site residing within a composite promoter of the human DBH gene, designated domain IV, in a cell-specific manner and directly controls noradrenergic-specific DBH promoter activity. In this report, we demonstrate that three additional protein-binding sites (i.e., domains I, II, and III) between domain IV and the TATA box are critical for intact DBH promoter activity in noradrenergic cells and that they activate DBH transcription in a highly concerted manner. Transient transfection assays of mutant DBH reporter constructs indicated that domain I was active in every cell line tested, whereas domain III was preferentially active in DBH-positive cells. Remarkably, mutation of domain II was associated with inactivation of DBH promoter activity exclusively in DBH-positive cell lines, defining it as another noradrenergic-specific promoter element. The cell-specific profile of the promoter function of these sequence motifs was further supported by in vitro DNA-binding studies and Southwestern analysis. Furthermore, competition and antibody supershift assays show that transcription factors Sp1 and AP2 are the cognate nuclear factors interacting with domains I and III, respectively. Parallel evidence indicates that domain II is another Phox2a-binding site, demonstrating at least two binding sites for this factor in the upstream DBH promoter. Strikingly, four tandem copies of domain II increased the promoter activity of a minimal DBH promoter by 100- to 200-fold in DBH-positive cell lines without compromising cell specificity. Cotransfection of Phox2a-expression vector dramatically increased the activity of the multiple domain II promoter only in DBH-negative cell lines, confirming that domain II is responsive to Phox2a. Collectively, this study emphasizes a critical role of Phox2a as well as its functional synergism with other transcription factors (e.g., CREB, AP2, and Sp1) in transcriptional activation of the DBH gene.

Animals↗

Requirement of corepressor binding of thyroid hormone receptor mutants for dominant negative inhibition.

Resistance to thyroid hormone (RTH) is mainly caused by dominant negative inhibition of wild type thyroid hormone receptor (TR) function due to mutations in the ligand binding domain of the TR beta. Because no RTH mutant was identified in the hinge region of the TR, the contribution of this region for dominant negative inhibition was explored. In transient transfection assays, the dominant negative activity of a RTH-type mutant (P453X) was abolished by an introduction of a mutation into the hinge region (P214R). Although this hinge mutation did not alter homo- or heterodimerization with retinoid X receptor (RXR), its association with nuclear receptor corepressor (N-CoR) was impaired. These results indicate that association of corepressor with the RTH mutants through the hinge region is crucial for their dominant negative activity.

Binding Sites↗

Molecular cloning of sucrase-isomaltase cDNA in the house musk shrew Suncus murinus and identification of a mutation responsible for isolated sucrase deficiency.

Isolated sucrase deficiency has been demonstrated in a line of house musk shrew, Suncus murinus (laboratory name: suncus). This animal belongs to the order Insectivore and is phylogenetically different from ordinarily used laboratory animals. They are believed to have evolved with mainly animal food without sucrose. To study the molecular basis of the sucrase deficiency in suncus, we cloned 6. 0-kilobase (kb) sucrase-isomaltase (SI, EC 3.2.1.48-10) cDNA from suncus intestinal cDNA library. The cDNA clone contained a 5442-base pair (bp)-long open reading frame preceded by an in frame termination codon. The deduced 1813-amino acid sequence showed 68.6, 71.2, and 74.7% similarity with those of rat, rabbit, and human, respectively. A cleavage site between isomaltase and sucrase as well as the region surrounding the catalytic sites for sucrase and isomaltase were conserved among the species. Out of 18 potential N-linked glycosylation sites, 5 were common among all 4 species. In the connecting segment which was enriched with O-linked glycosylation sites in the other species, only two sites were present in suncus. Northern blot analysis revealed that the 6.0-kb SI mRNA was expressed in the KAT line with intact sucrase-isomaltase activity. In contrast, 3.0-kb SI mRNA was expressed in suncus of the MI line with isolated sucrase deficiency. The 3.0-kb mRNA cosegregated with sucrase deficiency phenotype as an autosomal recessive trait. Sequence analysis revealed a 2-nucleotide deletion at position 2767-2768, which results in a frameshift and an immature termination codon. The cDNA of the MI line diverged from that of the KAT line at position 2865, having an 18-bp unique sequence followed by a poly(A) tail. The mutant cDNA encodes 922 amino acid residues which preserves the region for isomaltase but lacks that for whole sucrase. While the cells transfected with the plasmids expressing SI in the KAT line showed both sucrase and isomaltase activity, the plasmids expressing MI line cDNA showed only isomaltase activity. Thus it was concluded that the mutation in the SI gene was responsible for isolated sucrase deficiency in the MI line.

Amino Acid Sequence↗

A novel approach to identify proteins associated with the inhibition of neurite growth.

In the present study, a novel combination of techniques was used to identify the genes that may be involved in the lack of axonal regeneration in the mammalian adult central nervous system (CNS). The key features of this approach are: (1) a functional assay that can be affected by antibody perturbation; (2) increased specificity of the polyclonal antiserum by adsorption; (3) the expression cloning of the genes from a lambdagt11 library; (4) amplification of the insert cDNA by PCR; and (5) the direct cycle sequencing of PCR products. In this culture assay system, neurons were plated directly on sections of the rat CNS. This assay system could be used to demonstrate the lack of neuronal attachment to or neurite extension over myelinated regions of the CNS (white matter). This prohibitive nature of the CNS sections could be masked by a rabbit polyclonal antiserum directed against rat CNS white matter. This data indicates that the anti-white matter antiserum recognizes and neutralizes inhibitory molecules on the surface of the sections. Making the assumption that the prohibitive antigen is associated with the cell membrane, the antiserum was adsorbed against a soluble protein fraction of the adult rat brain. This adsorption significantly increased the specificity of the antiserum as demonstrated by immunoblot methods. The adsorbed antiserum was then used to screen the cDNA library of the adult rat brain. The present report describes this novel combination of techniques allowing one to go from a functional tissue culture assay system to defining the molecular basis for the cellular interactions.

Adsorption↗

Effects of thyroid status on expression of voltage-gated potassium channels in rat left ventricle.

OBJECTIVE: Thyroid hormone modifies cardiac action potentials and outward potassium currents directly and indirectly e.g. through beta-adrenergic signaling pathway. We thus examined the expression of six voltage-gated potassium channel alpha-subunits in the rat left ventricle under hypo- and hyperthyroid status, and tested roles of beta-adrenergic signaling pathway in their expressions under both status. METHODS: Hypothyroidism and hyperthyroidism were induced by administration of methimazole (MMI) for 4 weeks and by injection of L-thyroxine (T4) to the MMI-treated rats for the last 7 days, respectively. To distinguish the effects of T4 and the beta-adrenergic system, propranolol (Pro) was administered to the MMI-treated rats together with T4, and isoproterenol (Iso) was injected to MMI-treated rats for the last 7 days. The mRNA levels of Kv1.2, Kv1.4, Kv1.5, Kv2.1, Kv4.2 and Kv4.3 in the left ventricles were determined by ribonuclease protection assay. RESULTS: MMI treatment induced hypothyroidism and resulted in a significant decrease in the mRNA levels of Kv1.5, Kv2.1 and Kv4.2 (19%, 77% and 61% of control value, respectively; n = 6, p < 0.05). T4 administration induced hyperthyroidism and cardiac hypertrophy, and it increased the Kv1.5 and Kv2.1 mRNA levels over the control value (212% and 140%, respectively; n = 6, p < 0.05). Kv4.2 mRNA level was restored to the control level by T4. In contrast, the Kv1.2 and Kv1.4 mRNA levels increased in hypothyroid rats (161% and 186% of control value, respectively; n = 6, p < 0.01) and decreased in hyperthyroid rats (14% and 33% of control value, respectively; n = 6, p < 0.01). The Kv4.3 mRNA level was not altered by thyroid status. Pro did not inhibit the T4-induced hypertrophy. Iso induced cardiac hypertrophy. Pro or Iso by itself did not alter Kv mRNA levels except for Kv1.2, the message of which was decreased by Iso. CONCLUSION: Thyroid hormone differentially regulates the expression of Kv1.4, Kv1.5, Kv2.1 and Kv4.2 mRNA levels in the rat left ventricle. This effect is not mediated through beta-adrenergic signaling pathway. On the other hand, the reduction in Kv1.2 mRNA level was associated with cardiac hypertrophy induced by T4 or Iso.

Adrenergic beta-Agonists↗

Identification and characterization of potential cis-regulatory elements governing transcriptional activation of the rat tyrosine hydroxylase gene.

Tyrosine hydroxylase (TH) catalyzes the conversion of L-tyrosine to 3,4-dihydroxy-L-phenylalanine, which is the first and rate-limiting step in catecholamine biosynthesis. We have previously shown that the cyclic AMP response element (CRE), an essential promoter element for both basal and cyclic AMP-inducible TH transcription, activates the promoter activity in a distance-dependent manner. To identify further cis-regulatory elements controlling TH gene expression, we analyzed the potential regulatory sequences by several approaches. First, using transient transfection assays, we examined the cell-specific promoter activities of TH-reporter gene constructs and a dopamine beta-hydroxylase (DBH)-reporter construct containing the 5' upstream sequences of the rat TH and human DBH genes, respectively, that had been shown to direct tissue-specific reporter expression in transgenic mice experiments. Second, DNase I footprinting analysis of the 503-bp proximal area of the rat TH gene identified seven footprinted regions that encompass the putative cis-regulatory motifs, including the CRE (domain 1), Sp1 (domain III), Octamer (domain IV), AP1 (domain V), AP2 (domain VI), and two potentially novel sequence motifs (domains II and VII). Footprinting patterns at these sites by nuclear proteins from TH-positive and -negative cell lines appeared to be similar. Third, site-directed mutagenesis demonstrates that domain III, but not domain II, critically contributes to the TH promoter activity. Furthermore, electrophoretic mobility shift, competition, and supershift assays demonstrate that domain III is an authentic Sp1 site and that the transcription factor Sp1 interacts with it. This and previous results suggest that the CRE and Sp1 site may synergistically activate TH transcription in a promoter context-dependent manner.

3T3 Cells↗

Paired-like homeodomain proteins, Phox2a and Phox2b, are responsible for noradrenergic cell-specific transcription of the dopamine beta-hydroxylase gene.

Recently, a murine paired-like homeobox gene, Phox2a, has been identified whose product is critical for the development of several major noradrenergic neuron populations, including the locus coeruleus. In noradrenergic neurons, dopamine beta-hydroxylase (DBH) is a hallmark protein and catalyzes the conversion of dopamine to noradrenaline. Our previous studies have shown that a composite promoter (domain IV), residing at -185 to -150 bp upstream of the transcription start site, is critical for DBH transcription and is comprised of multiple cis-acting elements, including a cyclic AMP response element, a YY1 binding site, and two core motifs of the homeodomain (HD)-binding site. Here, we show that the HD-binding site residing within domain IV is a noradrenergic-specific cis-acting element. In contrast, the cyclic AMP response element is active in all cell lines tested. We provide evidence that Phox2a is expressed only in DBH-positive cell lines and interacts with the HD-binding site. Forced expression of Phox2a robustly activates DBH promoter activity in DBH-negative cell lines (>10-fold), but increased it only marginally (<50%) in DBH-positive cell lines. Furthermore, another protein factor with an identical HD, Phox2b, also activates DBH transcription with an efficiency comparable to that of Phox2a. In contrast, neither Phox2a nor Phox2b was able to transactivate tyrosine hydroxylase transcription, indicating that these transcription factors differentially activate catecholamine-synthesizing gene transcription. Together with the Phox2a knockout experiment, the studies described here make Phox2a and Phox2b the first strong candidate transcription factors for determining a neurotransmitter phenotype in vertebrates.

Animals↗

Inductions of immediate early genes (IEGS) and ref-1 by human chorionic gonadotropin in murine Leydig cell line (MA-10).

The effect of human chorionic gonadotropin (hCG) on the expression of immediate early genes (IEGs) including all members of fos and jun family, and c-myc was studied using mouse Leydig cell line (MA-10 cells) by Northern blot analyses. In addition, the induction of ref-1 which enhances DNA binding of fos/jun proteins was also analyzed. HCG induced a rapid and transient expression of c-fos, fosB, c-jun, junB, junD and c-myc with a peak at 30 min to 1 h. In contrast, induction of fra-1 mRNA was delayed with a peak at 3 hr. However, fra-2 mRNA was immediately increased by hCG with a peak at 1 h. The ref-1 mRNA was expressed before the stimulation and its level was not altered by hCG at least for 8 hr. The differential induction of IEGs and continuous expression of ref-1 mRNA suggest an important role of their gene products on the regulation of Leydig cell function by hCG.

Animals↗

Thyroid hormone action on liver, heart, and energy expenditure in thyroid hormone receptor beta-deficient mice.

Thyroid hormone (TH) responsive genes can be both positively and negatively regulated by TH through receptors (TR) alpha and beta expressed in most body tissues. However, their relative roles in the regulation of specific gene expression remain unknown. The TR beta knockout mouse, which lacks both TR beta1 and TR beta2 isoforms, provides a model to examine the role of these receptors in mediating TH action. TR beta deficient (TR beta-/-) mice that show no compensatory increase in TR alpha, and wild-type (TR beta+/+) mice of the same strain were deprived of TH by feeding them a low iodine diet containing propylthiouracil, and were then treated with supraphysiological doses of L-T3 (0.5, 5.5, and 25 microg/day/mouse). TH deprivation alone increased the serum cholesterol concentration by 25% in TR beta+/+ mice and reduced it paradoxically by 23% in TR beta-/- mice. TH deprivation reduced the serum alkaline phosphatase (AP) concentration by 31% in TR beta+/+ mice but showed no change in the TR beta-/- mice. Treatment with L-T3 (0.5 to 25 microg/mouse/day) caused a 57% decrease in serum cholesterol and a 231% increase in serum AP in the TR beta+/+ mice. The TR beta-/- mice were resistant to the L-T3 induced changes in serum cholesterol and showed increase in AP only with the highest L-T3 dose. Basal heart rate (HR) in TR beta-/- mice was higher than that of TR beta+/+ mice by 11%. HR and energy expenditure (EE) in both TR beta+/+ and TR beta-/- mice showed similar decreases (49 and 46%) and increases (49 and 41%) in response to TH deprivation and L-T3 treatment, respectively. The effect of TH on the accumulation of messenger RNA (mRNA) of TH regulated liver genes was also examined. TH deprivation down regulated spot 14 (S14) mRNA and showed no change in malic enzyme (ME) mRNA in both TR beta+/+ and TR beta-/- mice. In contrast treatment with L-T3 produced an increase in S14 and ME but no change in TR beta-/- mice. From these results, it can be concluded that regulation of HR and EE are independent of TR beta. With the exception of serum cholesterol concentration and liver ME mRNA accumulation, all other markers of TH action examined during TH deprivation exhibited the expected responses in the absence of TR beta. Thus, as previously shown for serum TSH, TR beta is not absolutely necessary for some changes typical of hypothyroidism to occur. In contrast, except for HR and EE, the full manifestation of TH-mediated action required the presence of TR beta.

Alkaline Phosphatase↗

Activation of transcriptionally active nuclear factor-kappaB by tumor necrosis factor-alpha and its inhibition by antioxidants in rat thyroid FRTL-5 cells.

ABSTRACT Tumor necrosis factor-alpha (TNF-alpha) exerts pleiotropic effects on thyroid follicular cells. However, the intracellular signaling pathway for the TNF-alpha action has not been well elucidated. The present study examined the effects of TNF-alpha on the activation of nuclear factor-kappa B (NF-kappaB) and on the expression of interleukin (IL)-6 gene in rat thyroid FRTL-5 cells. The treatment of the cells with TNF-alpha resulted in the nuclear translocation of p65-p50 heterodimer as well as p50-p50 homodimer NF-kappaBs. The treatment with the antioxidants 20 mM N-acetyl-L-cysteine (NAC) and 10 microM pyrrolidine dithiocarbamate (PDTC) inhibited the TNF-alpha-dependent activation of p65-p50 heterodimer but not the p50-p50 homodimer, indicating that generation of oxidants is required for the activation of the heterodimer NF-kappaB. When the plasmid containing the multimerized NF-kappaB sites upstream of a luciferase reporter gene was transfected into FRTL-5 cells, the treatment with NAC or PDTC prevented the TNF-alpha-dependent increase in the luciferase activities, indicating that the p65-p50 heterodimer is a transcriptionally active NF-kappaB. Accordingly, the TNF-alpha-dependent increase in IL-6 messenger RNA and in secretion of the protein was prevented by the treatment with NAC. These results strongly suggest that TNF-alpha increases the IL-6 gene expression through the activation of NF-kappaB in the thyroid cells, and that antioxidants suppress the TNF-alpha-dependent IL-6 expression by inhibiting the activation of the transcriptionally active NF-kappaB.

Animals↗

Diagnostic approach in exercise testing to detect a significant narrowing of the left anterior descending coronary artery in inferior vs posterior myocardial infarction.

To detect a significant narrowing of the left anterior descending artery in patients with inferior/posterior myocardial infarction, 200 patients underwent standard exercise testing. Age, gender, and grade of stenosis of the left anterior descending artery were similar in 138 patients with inferior myocardial infarction and 62 with posterior myocardial infarction. In patients with left anterior descending artery stenosis, there were more lateral leads with ST-segment depression (1.8+/-1.0 vs 1.1+/-1.1; p<0.01) and fewer anterior leads with ST-segment depression (2.1+/-1.4 vs 2.9+/-1.4; p=0.02) in those with inferior myocardial infarction than in those with posterior myocardial infarction. Applying the criterion of exercise-induced ST-segment depression > or = 0.1 mV, sensitivities and specificities in detecting left anterior descending artery stenosis were 98% and 21% respectively in inferior myocardial infarction and 94% and 26% respectively in posterior myocardial infarction. In contrast, discriminant analysis revealed sensitivities and specificities of 77% and 91% respectively in inferior myocardial infarction and 71% and 81% respectively in posterior myocardial infarction using the variables related to severity of inducible ischemia and lateral and anterior lead ST-segment depression. These results indicate that a multivariate approach underscoring the site of myocardial infarction can help in identifying stenosis of the left anterior descending artery in patients with inferior/posterior myocardial infarction.

Adult↗

TNF-alpha increases expression of IL-6 and ICAM-1 genes through activation of NF-kappaB in osteoblast-like ROS17/2.8 cells.

Tumor necrosis factor-alpha (TNF-alpha) plays a key role in inflammatory diseases such as rheumatoid arthritis and in postmenopausal osteoporosis. In various tissues, TNF-alpha action is mediated by a transcription factor, nuclear factor-kappa B (NF-kappaB). However, little is known about how TNF-alpha exerts its action in osteoblasts. We thus examined the effect of TNF-alpha on the activation of NF-kappaB in rat osteoblast-like osteosarcoma cells (ROS17/2.8). Electrophoretic mobility shift assay revealed that the activation of the p50-p65 heterodimer NF-kappaB was induced by TNF-alpha as early as 15 minutes followed by a persistent activation for 48 h. When the binding activity of NF-kappaB in cytosol was examined using detergents that dissociate NF-kappaB from an inhibitory protein IkappaB, it decreased during the initial 30 minutes and then increased to the unstimulated level. Northern blot analysis revealed a marked increase in the mRNA levels of p105, a precursor of p50, 6 h after TNF-alpha and a gradual increase in p65 mRNA levels during the initial 1 h. Significant increase in both mRNA levels continued until 24 h after TNF-alpha. These results suggest that the rapid activation of NF-kappaB by TNF-alpha is mainly due to the nuclear translocation of NF-kappaB pre-existing in cytosol, and that the subsequent increase in the expression of p50 and p65 may result in the persistent activation of NF-kappaB during TNF-alpha stimulation. TNF-alpha also increased the mRNA levels of interleukin-6 (IL-6) and intercellular adhesion molecule-1 (ICAM-1). An antioxidant, N-acetyl-L-cysteine, significantly attenuated the TNF-alpha-dependent increase in these mRNAs, and simultaneously reduced the activation of NF-kappaB by TNF-alpha, indicating that NF-kappaB mediates the TNF-alpha-dependent expression of IL-6 and ICAM-1 in ROS17/2.8 cells. These results suggest that the activation of NF-kappaB by TNF-alpha may play an important role in the production of cytokines and cell adhesion molecules from osteoblasts, leading to the promotion of bone resorption and inflammation.

Acetylcysteine↗

[Blood pressure and diastolic function in the elderly].

To evaluate the relation between blood pressure and diastolic function in the elderly, 28 apparently healthy volunteers underwent blood pressure measurements, echocardiographic examinations, and radionuclide angiography acquired in list mode. Casual blood pressure did not correlate with diastolic indices measured either by echocardiography or by a radionuclide method, except for peak filling rate during atrial contraction assessed by radionuclide angiography (r = 0.39, p < 0.05). Ambulatory blood pressure monitoring revealed significant correlations between peak filling rate during atrial contraction assessed by radionuclide angiography and blood pressure measured over 24 hours, while awake and during sleep. The time to peak filling rate and the velocity of early diastolic filling were found to correlate with blood pressure, but the best correlation was between blood pressure during sleep and peak filling rate during atrial contraction (r = 0.53, p < 0.005). These results show a direct relation between blood pressure and diastolic function in the elderly, which is stronger during sleep than during wakefulness.

Aged↗