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C Lenz

Publications and source records attributed to C Lenz.

At least 19 recordsLinked to original sources
PubMed2001

Molecular cloning of a functional allatostatin gut/brain receptor and an allatostatin preprohormone from the silkworm Bombyx mori.

The cockroach-type or A-type allatostatins are inhibitory insect neuropeptides with the C-terminal sequence Tyr/Phe-X-Phe-Gly-Leu-NH(2). Here, we have cloned an A-type allatostatin receptor from the silkworm Bombyx mori (BAR). BAR is 361 amino acid residues long, has seven transmembrane domains, shows 60% amino acid residue identity with the first Drosophila allatostatin receptor (DAR-1), and 48% identity with the second Drosophila allatostatin receptor (DAR-2). The BAR gene has two introns and three exons. These two introns coincide with and have the same intron phasing as two introns in the DAR-1 and DAR-2 genes, showing that the three receptors are not only structurally but also evolutionarily related. Furthermore, we have cloned a Bombyx allatostatin preprohormone that contains eight different A-type allatostatins. Chinese hamster ovary cells permanently transfected with BAR DNA react on the addition of 4 x 10(-9)M Bombyx A-type allatostatins with a second messenger cascade (measured as bioluminescence), showing that BAR is a functional A-type allatostatin receptor. Southern blots suggest that Bombyx has at least one other BAR-related gene in addition to the BAR gene described in this paper. Northern blots and quantitative reverse transcriptase-polymerase chain reaction of different larval tissues show that BAR mRNA is mainly expressed in the gut and to a much lesser extent in the brain. To our knowledge, this is the first report on the molecular cloning and functional expression of an insect gut/brain peptide hormone receptor.

Amino Acid Sequence↗
PubMed2001

Identification of four Drosophila allatostatins as the cognate ligands for the Drosophila orphan receptor DAR-2.

The allatostatins are generally inhibitory insect neuropeptides. The Drosophila orphan receptor DAR-2 is a G-protein-coupled receptor, having 47% amino acid residue identity with another Drosophila receptor, DAR-1 (which is also called dros. GPCR, or DGR) that was previously shown to be the receptor for an intrinsic Drosophila A-type (cockroach-type) allatostatin. Here, we have permanently expressed DAR-2 in CHO cells and found that it is the cognate receptor for four Drosophila A-type allatostatins, the drostatins-A1 to -A4. Of all the drostatins, drostatin-A4 (Thr-Thr-Arg-Pro-Gln-Pro-Phe-Asn-Phe-Gly-Leu-NH(2)) is the most effective in causing a second messenger cascade (measured as bioluminescence; threshold, 10(-9) M; EC(50), 10(-8) M), whereas the others are less effective and about equally potent (EC(50), 8 x 10(-8) M). Northern blots showed that the DAR-2 gene is expressed in embryos, larvae, pupae, and adult flies. In adult flies, the receptor is more strongly expressed in the thorax/abdomen than in the head parts, suggesting that DAR-2 is a gut receptor. This is confirmed by Northern blots from 3rd instar larvae, showing that the DAR-2 gene is mainly expressed in the gut and only very weakly in the brain. The Drosophila larval gut also contains about 20-30 endocrine cells, expressing the gene for the drostatins-A1 to -A4. We suggest, therefore, that DAR-2 mediates an allatostatin (drostatin)-induced inhibition of gut motility. This is the first report on the permanent and functional expression of a Drosophila gut neurohormone receptor.

Amino Acid Sequence↗
PubMed2001

Influence of the small leader exons 2 and 3 on human immunodeficiency virus type 1 gene expression.

The human immunodeficiency virus type 1 (HIV-1) uses an elaborate alternative splicing pattern for the generation of both the 1.8-kb as well as the 4-kb classes of mRNA. An additional diversity of transcripts in both classes is created by the optional inclusion of the small exons 2 and 3 in the leader sequence. To analyze a possible influence of these leader exons on HIV-1 gene expression, several series of expression vectors with different leaders were constructed, expressing either Rev and Env or a heterologous coding sequence, i.e., the chloramphenicol acetyl transferase (CAT) ORF. Transfection experiments of HeLa-T4(+) cells revealed for all series of constructs that mRNA as well as protein expression was stimulated by the presence of exon 2 and reduced by exon 3. The function of the leader exons 2 and 3 is neither dependent on the regulatory proteins Tat or Rev nor on viral coding sequences. Neither transcription rates nor stability of polyadenylated RNAs were found to be responsible for the different levels of steady-state mRNA. When either exon 2 or 3 was inserted into a heterologous intron, processing of the primary transcripts generated identical mRNA species while maintaining the differences in exon 2/3-dependent mRNA steady-state levels. These results may be explained by exon-specific nuclear RNA degradation rates, as also indicated by results from an in vitro degradation assay using a HeLa nuclear extract.

Alternative Splicing↗
PubMed2001

Molecular cloning, genomic organization, and expression of a C-type (Manduca sexta-type) allatostatin preprohormone from Drosophila melanogaster.

The insect allatostatins are a diverse group of neuropeptides that obtained their names by their inhibitory actions on the corpora allata (two endocrine glands near the insect brain), where they block the biosynthesis of juvenile hormone (a terpenoid important for development and reproduction). Chemically, the allatostatins can be subdivided into three different peptide groups: the large group of A-type (cockroach-type) allatostatins, which have the common C-terminal sequence Y/FXFGLamide; the B-type (cricket-type) allatostatins, which have the C-terminal sequence W(X(6))Wamide in common; and a single allatostatin that we now call C-type allatostatin that was first discovered in the moth Manduca sexta, and which has a nonamidated C terminus, and a structure unrelated to the A- and B-type allatostatins. We have previously cloned the preprohormones for the A- and B-type allatostatins from Drosophila melanogaster. Here we report on the cloning of a Drosophila C-type allatostatin preprohormone (DAP-C). DAP-C is 121 amino acid residues long and contains one copy of a peptide sequence that in its processed form has the sequence Y in position 4) from the Manduca sexta C-type allatostatin. The DAP-C gene has three introns and four exons and is located at position 32D2-3 on the left arm of the second chromosome. Northern blots show that the gene is strongly expressed in larvae and adult flies, but less in pupae and embryos. In situ hybridizations of larvae show that the gene is expressed in various neurons of the brain and abdominal ganglia and in endocrine cells of the midgut. This is the first publication on the structure of a C-type allatostatin from insects other than moths and the first report on the presence of all three types of allatostatins in a representative of the insect order Diptera (flies).

Amino Acid Sequence↗
PubMed2001

Effect of testosterone on plaque development and androgen receptor expression in the arterial vessel wall.

BACKGROUND: -Recent studies have suggested that testosterone has a protective effect in the arterial vascular system. However, little is known about the molecular aspects of the mechanism(s) involved in these processes. The aim of the present study was to investigate the effect of testosterone on neointimal plaque development and on the expression of the vascular androgen receptor. Methods and Results-Neointimal plaque formation was induced by endothelial denudation in the aortas of male New Zealand White rabbits. Aortic ring segments were cultured for 21 days after endothelial denudation. Testosterone was applied to the culture medium in different doses. Compared with the non-hormone-treated control group, a significant inhibition of neointimal plaque development (expressed as the intima/media ratio) was found at testosterone concentrations of 10 ng/mL (P:=0.037) and 100 ng/mL (P:=0.012; intima/media ratios: median of controls, 0.25; median of 10 ng/mL testosterone group, 0.15; median of 100 ng/mL testosterone group, 0.16). Associated with this inhibitory effect on plaque size was a 50% increase of the amount of androgen receptor mRNA in the arterial segments treated with testosterone. CONCLUSION: -The beneficial effects of testosterone on postinjury plaque development underlines, at least in males, the important role of androgens in the vascular system. As our data suggest, the vascular androgen receptor is probably involved in these processes. Further studies are required to characterize the androgen receptor-dependent pathways in the vascular system.

Animals↗
PubMed2001

Molecular cloning, genomic organization, and expression of a B-type (cricket-type) allatostatin preprohormone from Drosophila melanogaster.

The insect allatostatins obtained their names because they block the biosynthesis of juvenile hormone (a terpenoid) in the corpora allata (two endocrine organs near the insect brain). Chemically, the allatostatins can be subdivided into three different peptide groups: the A-type allatostatins, first discovered in cockroaches, which have the C-terminal sequence Y/FXFGLamide in common; the B-type allatostatins, first discovered in crickets, which all have the C-terminal sequence W(X)(6)Wamide; and the C-type allatostatins, first discovered in the moth Manduca sexta, which have an unrelated and nonamidated C terminus. We have previously reported the structure of an A-type allatostatin preprohormone from the fruitfly Drosophila melanogaster. Here we describe the molecular cloning of a B-type prepro-allatostatin from Drosophila (DAP-B). DAP-B is 211 amino acid residues long and contains one copy each of the following putative allatostatins: AWQSLQSSWamide (drostatin-B1), AWKSMNVAWamide (drostatin-B2), <EAQGWNKFRGAWamide (drostatin-B3), EPTWNNLKGMWamide (drostatin-B4), and DQWQKLHGGWamide (drostatin-B5). All five drostatins are novel peptide structures. The DAP-B gene has one intron and two exons and is located at position 74B1 on the left arm of the third chromosome. The gene is expressed in all developmental stages, but weakly in embryos and strongly in larvae. In situ hybridizations of larvae showed that neurons in the brain and abdominal ganglia and endocrine cells in the gut expressed DAP-B. This is the first published report of a B-type allatostatin preprohormone in insects, and the first paper describing the presence of B-type allatostatins in a representative of the insect order Diptera (flies).

Amino Acid Sequence↗
PubMed2001

17beta-estradiol, gender independently, reduces atheroma development but not neointimal proliferation after balloon injury in the rabbit aorta.

The aim of the present study was to investigate anti-proliferative and anti-atherogenic properties of 17beta-estradiol in balloon injured female and male rabbit aortae. Thirty-two female and 32 male New Zealand White rabbits where gonadectomised. Vascular injury was performed with a balloon catheter in the lower abdominal aorta. Male and female rabbits were randomised into four groups of eight animals each. Only two of four groups received a 0.5% cholesterol-enriched diet. One cholesterol-diet group and one normal-diet group received intramuscular injections of estradiol valerate (1 mg/kg body weight/week). After 28 days, the denuded part of the abdominal aorta was excised and analysed by morphometry and immunohistochemistry. Estrogen treatment did not show an inhibitory effect on neointimal proliferation in normo-cholesterolemic male or female rabbits. A gender independent inhibitory effect of 17beta-estradiol was seen on atheroma development in cholesterol-fed female and male rabbits, while plasma total cholesterol levels were significantly reduced in male rabbits only. The 17beta-estradiol treatment was associated with a significantly decreased number of luminal endothelial cells in normo and hyper-cholesterolemic female rabbits, as evaluated by immunohistochemical staining for 'von Willebrand factor'. Staining for Ki-67-positive proliferating cells after 28 days showed a statistically significant increased proliferative activity in the neointima of hyper-cholesterolemic female rabbits. The neointimal content of macrophages increased significantly in all hyper-cholesterolemic rabbits. Under 17beta-estradiol treatment, the number of macrophages was increased in female and decreased in male rabbits by tendency. Additionally, the 'classical' vascular estrogen receptor was present in both female and male rabbit aortae without statistically significant differences. In conclusion, 17beta-estradiol did not reduce post-injury neointima formation in normo-cholesterolemic rabbits. However, in hyper-cholesterolemic rabbits, 17beta-estradiol reduced atheroma development gender independently. This effect cannot be explained by lowering of plasma cholesterol levels or endothelium-mediated pathways, and requires further investigation on, for example, antioxidative, antiproliferative or estrogen receptor mediated effects.

Actins↗
PubMed2001

Further isoflavonoid metabolites from Millettia griffoniana (Bail).

Three new isoflavonoids, griffonianone A (1), B (2) and C (4) were isolated from the root bark of Millettia griffoniana, along with the known maximaisoflavone G (5) and 7-hydroxy-6-methoxy-3',4'-methylenedioxyisoflavone (6). Their structures were assigned on the basis of spectroscopic data and chemical transformations.

Fabaceae↗
PubMed2001

Lack of hypercapnic increase in cerebral blood flow at high blood viscosity in conscious blood-exchanged rats.

BACKGROUND: The hypothesis of a compensatory dilation of cerebral vessels to maintain cerebral blood flow at a high blood viscosity was tested during hypercapnia in the study after replacement of blood by hemoglobin solutions of defined viscosities. If compensatory vasodilation exists at normocapnia at a high blood viscosity, vasodilatory mechanisms may be exhausted when hypercapnia is added, resulting in a lack of increase in cerebral blood flow at hypercapnia. METHODS: In conscious rats, blood was replaced by ultrapurified cross-linked hemoglobin solutions that had defined and shear rate-independent low or high viscosities (low- and high-viscosity groups). Blood viscosity differed threefold between both groups (1.2 vs. 3.6 mP x s). Thereafter, rats inhaled either a normal or an increased concentration of carbon dioxide in air. Cerebral blood flow was determined by the iodo[14C]antipyrine method. RESULTS: During normocapnia, global and local cerebral blood flows did not differ between both groups. With increasing degrees of hypercapnia, global and local cerebral blood flows were gradually elevated in the low-viscosity group (2.8 ml x mmHg(-1) CO2 x 100 g(-1) x min(-1)), whereas they remained unchanged in the high-viscosity group. CONCLUSIONS: Changes in blood viscosity do not result in changes of cerebral blood flow as long as cerebral vessels can compensate for these changes by vasodilation or vasoconstriction. However, such vascular compensatory adjustments may be exhausted in their response to further pathophysiologic conditions in blood vessels that have already been dilated or constricted as a result of changes in blood viscosity.

Animals↗
PubMed2001

Oxygen delivery at high blood viscosity and decreased arterial oxygen content to brains of conscious rats.

We addressed the question to which extent cerebral blood flow (CBF) is maintained when, in addition to a high blood viscosity (Bvis) arterial oxygen content (CaO2) is gradually decreased. CaO2) was decreased by hemodilution to hematocrits (Hct) of 30, 22, 19, and 15% in two groups. One group received blood replacement (BR) only and served as the control. The second group received an additional high viscosity solution of polyvinylpyrrolidone (BR/PVP). Bvis was reduced in the BR group and was doubled in the BR/PVP. Despite different Bvis, CBF did not differ between BR and BR/PVP rats at Hct values of 30 and 22%, indicating a complete vascular compensation of the increased Bvis at decreased CaO2. At an Hct of 19%, local cerebral blood flow (LCBF) in some brain structures was lower in BR/PVP rats than in BR rats. At the lowest Hct of 15%, LCBF of 15 brain structures and mean CBF were reduced in BR/PVP. The resulting decrease in cerebral oxygen delivery in the BR/PVP group indicates a global loss of vascular compensation. We concluded that vasodilating mechanisms compensated for Bvis increases thereby maintaining constant cerebral oxygen delivery. Compensatory mechanisms were exhausted at a Hct of 19% and lower as indicated by the reduction of CBF and cerebral oxygen delivery.

Animals↗
PubMed2000

Molecular cloning and genomic organization of an allatostatin preprohormone from Drosophila melanogaster.

The insect allatostatins are neurohormones, acting on the corpora allata (where they block the release of juvenile hormone) and on the insect gut (where they block smooth muscle contraction). We screened the "Drosophila Genome Project" database with electronic sequences corresponding to various insect allatostatins. This resulted in alignment with a DNA sequence coding for some Drosophila allatostatins (drostatins). Using PCR with oligonucleotide primers directed against the presumed exons of this Drosophila allatostatin gene and subsequent 3'- and 5'-RACE, we were able to clone its cDNA. The Drosophila allatostatin preprohormone contains four amino acid sequences that after processing would give rise to four Drosophila allatostatins: Val-Glu-Arg-Tyr-Ala-Phe-Gly-Leu-NH(2) (drostatin-1), Leu-Pro-Val-Tyr-Asn-Phe-Gly-Leu-NH(2) (drostatin-2), Ser-Arg-Pro-Tyr-Ser-Phe-Gly-Leu-NH(2) (drostatin-3), and Thr-Thr-Arg-Pro-Gln-Pro-Phe-Asn-Phe-Gly-Leu-NH(2) (drostatin-4). Drostatin-2 is identical to helicostatin-2 (11-18) and drostatin-3 to helicostatin-3, two neurohormones previously isolated from the moth Helicoverpa armigera. Furthermore, drostatin-3 has previously been isolated from Drosophila itself. Drostatins-1 and -4 are novel members of the insect allatostatin neuropeptide family. The Drosophila allatostatin preprohormone gene contains two introns and three exons. The gene is located on the right arm of the third chromosome, position 96A-B. The existence of at least four different Drosophila allatostatins opens the possibility of a differential action of some of these hormones on the two recently cloned Drosophila allatostatin receptors, DAR-1 and -2. This is the first report on an allatostatin preprohormone from Drosophila.

Amino Acid Sequence↗
PubMed2000

Molecular cloning and genomic organization of a second probable allatostatin receptor from Drosophila melanogaster.

We (C. Lenz et al. (2000) Biochem. Biophys. Res. Commun. 269, 91-96) and others (N. Birgül et al. (1999) EMBO J. 18, 5892-5900) have recently cloned a Drosophila receptor that was structurally related to the mammalian galanin receptors, but turned out to be a receptor for a Drosophila peptide belonging to the insect allatostatin neuropeptide family. In the present paper, we screened the Berkeley "Drosophila Genome Project" database with "electronic probes" corresponding to the conserved regions of the four rat (delta, kappa, mu, nociceptin/orphanin FQ) opioid receptors. This yielded alignment with a Drosophila genomic database clone that contained a DNA sequence coding for a protein having, again, structural similarities with the rat galanin receptors. Using PCR with primers coding for the presumed exons of this second Drosophila receptor gene, 5'- and 3'-RACE, and Drosophila cDNA as template, we subsequently cloned the cDNA of this receptor. The receptor cDNA codes for a protein that is strongly related to the first Drosophila receptor (60% amino acid sequence identity in the transmembrane region; 47% identity in the overall sequence) and that is, therefore, most likely to be a second Drosophila allatostatin receptor (named DAR-2). The DAR-2 gene has three introns and four exons. Two of these introns coincide with two introns in the first Drosophila receptor (DAR-1) gene, and have the same intron phasing, showing that the two receptor genes are clearly evolutionarily related. The DAR-2 gene is located at the right arm of the third chromosome, position 98 D-E. This is the first report on the existence of two different allatostatin receptors in an animal.

Amino Acid Sequence↗
PubMed2000

Molecular cloning and genomic organization of a novel receptor from Drosophila melanogaster structurally related to mammalian galanin receptors.

We screened the Berkeley "Drosophila Genome Project" database with "electronic probes" corresponding to conserved amino acid sequences from the five known rat somatostatin receptors. This yielded alignment with a Drosophila genomic clone that contained a DNA sequence coding for a protein, having amino acid sequence identities with the rat galanin receptors. Using PCR with Drosophila cDNA as a template, and oligonucleotide probes coding for the exons of the presumed Drosophila gene, we were able to clone the cDNA for this receptor. The Drosophila receptor has most amino acid sequence identity with the three mammalian galanin receptors (37% identity with the rat galanin receptor type-1, 32% identity with type-2, and 29% identity with type-3). Less sequence identity exists with the mammalian opioid/nociceptin-orphanin FQ receptors (26% identity with the rat micro opioid receptor), and mammalian somatostatin receptors (25% identity with the rat somatostatin receptor type-2). The novel Drosophila receptor gene contains ten introns and eleven exons and is located at the distal end of the X chromosome.

Amino Acid Sequence↗
PubMed2000

Functional expression of a multisubstrate deoxyribonucleoside kinase from Drosophila melanogaster and its C-terminal deletion mutants.

The occurrence of a deoxyribonucleoside kinase in Drosophila melanogaster (Dm-dNK) with remarkably broad substrate specificity has recently been indicated (Munch-Petersen, B., Piskur, J., and Søndergaard, L. (1998) J. Biol. Chem. 273, 3926-3931). To prove that the capacity to phosphorylate all four deoxyribonucleosides is in fact associated to one polypeptide chain, partially sequenced cDNA clones, originating from the Berkeley Drosophila genome sequencing project, were searched for homology with human deoxyribonucleoside kinases. The total sequence of one cDNA clone and the corresponding genomic DNA was determined and expressed in Escherichia coli as a glutathione S-transferase fusion protein. The purified and thrombin cleaved recombinant protein phosphorylated the four deoxyribonucleosides with high turnover and K(m) values similar to those of the native Dm-dNK, as well as the four ribonucleosides and many therapeutical nucleoside analogs. Dm-dNK has apparently the same origin as the mammalian kinases, thymidine kinase 2, deoxycytidine kinase, deoxyguanosine kinase, and the herpes viral thymidine kinases, but it has a unique C terminus that seems to be important for catalytic activity and specificity. The C-terminal 20 amino acids were dispensable for phosphorylation of deoxyribonucleosides but necessary for full activity with purine ribonucleosides. Removal of the C-terminal 20 amino acids increased the specific activity 2-fold, but 99% of the activity was lost after removal of the C-terminal 30 amino acids.

Amino Acids↗
PubMed2000

[Detection of numerical chromosome aberrations in leukoplakia and squamous epithelial carcinomas of the head-neck area using fluorescence in situ hybridization].

The tumorigenesis of head and neck squamous cell carcinoma (HNSCC) has been proposed to represent a multistep process characterized by an accumulation of genetic alterations. To study numerical chromosomal aberrations and chromosomal imbalances, biopsies of 11 malignant tumours and biopsies of 16 oral premalignant lesions (leukoplakias) were analyzed by fluorescence in situ hybridization (FISH) using centromeric probes for chromosomes, 1, 7, 9, 10 and 17. The comparison of the alterations observed in simple leukoplakias (group 1, n = 8), dysplastic leukoplakias (group 2, n = 8) and malignant tumours (group 3, n = 11) by the Cochran-Armitage Trend Test revealed an increasing number of numerical chromosomal abberations. This difference was statistically highly significant (p < 0.001). The data open up the possibility that FISH analysis might help to better characterize the progression of premalignant oral leukoplakias.

Biopsy↗
PubMed2000

[The effects of estrogen in the cardiovascular system].

Estrogen replacement therapy (ERT) has been established for the treatment of perimenopausal symptoms and postmenopausal prevention of osteoporosis. Clinical (not randomized) cohort studies have shown an association of a significantly reduced cardiovascular mortality with ERT. However, a first randomized, double-blind and placebo-controlled study (HERS) could not support these findings. However, this study is limited by the use of (heterogeneous) conjugated estrogens and combined progestin treatment because animal experiments demonstrated an inhibition of protective estrogen effects by progesterone. On the other hand, experimental and clinical findings demonstrated beneficial estrogen effects on lipid metabolism, lipid-peroxidation, smooth-muscle-cell proliferation, hemostasis, and vasomotion. Actually, several authors are discussing the mediation of estrogen's effects by vascular estrogen receptors. Recent findings on different subtypes of estrogen receptors (ER-alpha and ER-beta) may explain some antagonistic effects as proliferation in the one (endometrium) and anti-proliferation in the other (vascular wall) tissue. In this context, the exact detection of the mechanism(s) of estrogen action may probably lead to new approaches in the treatment of coronary artery disease.

Animals↗
PubMed2000

Incidence of intimal proliferation and apoptosis following balloon angioplasty in an atherosclerotic rabbit model.

OBJECTIVE: The aim of this study was to determine the occurrence of apoptosis in relation to the proliferative response in the intimal layer after experimental balloon angioplasty of a pre-existing plaque. METHODS: After induction of an intimal plaque in the right carotid artery by electrical stimulation, 26 rabbits underwent balloon angioplasty. Twelve animals served as a control group without performance of angioplasty after plaque induction. To study the time course of intimal apoptosis and cell proliferation the vessels were excised on day 7, 14 and 28 after balloon angioplasty. For in situ detection of apoptosis, the TUNEL-technique (TdT-mediated d-UTP fluorescein nick end labeling) was used. In addition, bromodeoxyuridine labeling in all animals allowed the determination of the percentage of cells undergoing DNA synthesis in the neointimal area. Additionally, smooth muscle cells were detected by immunostaining of alpha-actin and macrophages by a specific antibody (RAM 11). RESULTS: Within 28 days of balloon angioplasty, the number of cells undergoing apoptosis remained at a very low level and was not significantly different to the control group without interventional treatment (controls: 0.1 +/- 0.15%; 7 days: 0.44 +/- 0.68%; 14 days: 0.13 +/- 0.11%; 28 days: 0.1 +/- 0.1%). In contrast, the number of cells undergoing DNA synthesis was significantly increased at day 7 after angioplasty (3.72 +/- 2.0% vs. 0.51 +/- 0.29% in controls), resulting in an increase of the total intimal area from 0.088 +/- 0.037 mm2 in the control animals up to 0.256 +/- 0.172 mm2 at day 28 following balloon dilatation. CONCLUSIONS: Our data showed that significant changes in the occurrence of apoptosis are not involved in the regulation of cellular turnover during the examined time period after vessel wall injury. The lacking up-regulation of apoptosis in comparison to the increased cell proliferation in order to maintain the tissue balance is perhaps an important regulatory mechanism leading to intimal hyperplasia after vascular injury in this animal model. Overall, we suggest that there may be a delicate balance between cell proliferation and apoptosis in smooth muscle cells of the vessel wall, and only small shifts in this balance could account for both cellular accumulation in restenotic lesions as well as cell death in mature atheroma.

Analysis of Variance↗