BACKGROUND: Proliferation of vascular smooth muscle cells(VSMC) is a critical event in the development of atherosclerosis. Endothelin-1(ET-1), a vasoconstrictor peptide produced by endothelial cells and VSMC, might play a role in vascular remodeling. To investigate the proposed 'mitogenic' potential of ET-1, we examined the effects of ET-1 on the proliferation if cultured porcine aortic VSMC and on the potential synergism with platelet-derived growth factor(PDGF). MATERIALS AND METHODS: VSMC were obtained from porcine aorta and cultured in Dulbecco's modified Eagle medium supplmented with 10% fetal bovine serum(FBS). VSMC grown subconfluently in 12-well plate were stimulated by ET-1, PDGF, and ET-1 & PDGF and DNA synthesis was determined as the uptake of 3H-thymidine into cell cultures. We also examined the effects of BQ123, a selective ETA receptor antagonist, and NG-methyl-L-arginine(NMLA), a nitric oxide synthase (NOS) inhibitor. RESULTS: ET-1 elicited a 2.5-fold increase of cultured VSMC DNA synthesis, comparing with basal medium, and PDGF elicited a 4.8-fold increase, whereas ET-1 and PDGF elicited a 8.8-fold increase, showing synergistic effect. Proliferative activity of ET-1 on VSMC was blocked(39%) by BQ123, however, the synergistic effect of ET-1 and PDGF was not blocked by BQ123. The synergistic effect of ET-1 and PDGF was increased when co-stimulated with NMLA. CONCLUSION: ET-1 is a co-mitogen for VSMC from porcine aorta, whose proliferative activity requires serum or other growth factors such as PDGF for its maximal activity. The proliferative activity of ET-1 is considered to be transduced partly by selective activation of the ETA receptor, however, the synergistic effect of of ET-1 and PDGF is to be stimulated by non-ETA receptor.
Aorta ; Atherosclerosis ; Cell Culture Techniques ; Cell Proliferation* ; DNA ; Eagles ; Endothelial Cells ; Endothelin-1* ; Intercellular Signaling Peptides and Proteins ; Muscle, Smooth, Vascular* ; Nitric Oxide Synthase

BACKGROUND: Many studies reported that endothelium-dependent vasodilator response is impaired in patients with congestive heart failure. But the opposite results also were reported. The aim of this study was to determine the presence of endothelial dysfunction and its characteristics. METHODS AND MATERIALS: Forearm blood flow was measured in 12 patients with congestvie heart failure (7 males and 5 females, mean age 53+/-11 years old) and 10 normal control subjects (5 males and 5 females, mean age 41+/-10 years old) using strain-gauge plethysmography. The endothelium-dependent vasodilators were acetylcholine (7.5, 15, and 30 microgram/min), which uses a pertussis toxin-sensitive signal transduction pathway, and bradykinin (100, 200, and 400 ng/min), which uses a pertussis toxin-insensitive signal transduction pathway to activate nitric oxide production. Sodium nitroprusside (0.8, 1.6, and 3.2 microgram/min) was used as an endothelium-independent vasodilator. All drugs were infused into the brachial artery with random order. RESULTS: The basal forearm blood flow was similar between both groups. The maximum flow in response to acetylcholine, bradykinin, and sodium nitroprusside was also similar in two groups. CONCLUSIONS: Patients with congestive heart failure showed normal endothelium-dependent vasodilator responses to both acetylcholine and to bradykinin. This finding indicates that the endothelial vasodilator function is normal in the patients with heart failure.
Acetylcholine ; Brachial Artery ; Bradykinin ; Endothelium ; Endothelium-Dependent Relaxing Factors ; Estrogens, Conjugated (USP)* ; Female ; Forearm ; Heart Failure* ; Humans ; Male ; Nitric Oxide ; Nitroprusside ; Plethysmography ; Signal Transduction ; Vasodilation* ; Whooping Cough

No abstract available.
Heart Septal Defects, Ventricular* ; Thorax*

No abstract available.
Pneumothorax* ; Thorax*

Isolated rat thoracic aorta which is pharmacologically precontracted by phenylephrine induces photorelaxation when exposed to long wave length UV-light. The aim of the present study was to characterize the mechanism of UV-light induced by photorelaxation in the rat aorta. 1. UV light relaxed both endothelium-intact and -denuded rat aortic rings contracted by phenylephrine. The magnitude of relaxation on UV light was dependent on the exposure time and slightly greatly in endothelium-denuded rings than in endothelium-intact preparations. 2. L-NAME (10 nM-100 uM) but not D-NAME completely inhibited the photorelaxation in a concentration dependent manner. 3. The UV-induced relaxation was inhibited by methylene blue (1 -100 uM), and verapamil (100 nM), and removal of extracellular Ca2+. In contrast, UV-light induced photorelaxation was potentiated by N(w)-nitro-Larginine (L-NOARG) treatment. 4. In immunocytochemical analysis of UV-light induced iNOS and eNOS expression in rat aortas, at which expression levels were increased in a time-dependent manner on UV-irradiation in aortic endothelium and smooth muscle, respectively. These results suggest that UV light-induced photorelaxation may be due to nitric oxide from exogenously administered L-arginine as well as endogenous nitric oxide donors such as amino acid and arginine derivatives. Additional suggestion is that UV light stimulates the expression of nitric oxide synthases, and its activity for nitric oxide generation is dependent on cytosolic Ca2+ originated from extracellular space.
Acetylcholine/pharmacology ; Animals ; Aorta, Thoracic/drug effects/*physiology/radiation effects ; Calcium Channel Blockers/pharmacology ; Cholinergic Agents/pharmacology ; Endothelium, Vascular/drug effects/physiology/radiation effects ; Enzyme Inhibitors/pharmacology ; Female ; Male ; Methylene Blue/pharmacology ; NG-Nitroarginine Methyl Ester/pharmacology ; Nitric Oxide Synthase/antagonists & inhibitors/metabolism ; Phenylephrine/pharmacology ; Rats ; Rats, Sprague-Dawley ; *Ultraviolet Rays ; Vasoconstrictor Agents/pharmacology ; Vasodilation/drug effects/*radiation effects ; Vasodilator Agents/pharmacology ; Verapamil/pharmacology

No Abstract Available.
DNA* ; Interleukin-12* ; Mycobacterium tuberculosis* ; Mycobacterium*

No abstract available.
Esophageal Neoplasms*

To clarify the mechanism of the protective effect of hemodialysis on lipid peroxidation in RBC membrane structures, the level of malondialdehyde (MDA) which is the lipid peroxidation product, and the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase, and glutathione peroxidase (GSH-Px) were determined before and after hemodialysis in the RBCs from 20 patients with end stage renal disease (ESRD), and from 14 healthy subjects. Before dialysis, MDA levels in the RBCs from the patients with ESRD were higher than those from healthy controls. SOD and catalase activities in the RBCs were lower. After hemodialysis, MDA, SOD, and catalase in the RBCs from the patients with ESRD were normalized. These results indicate that hemodialysis treatment is helpful to protect the peroxidative darnage through normalizing the activities of antioxidant enzymes.
Catalase ; Dialysis ; Erythrocytes* ; Glutathione Peroxidase ; Humans ; Kidney Failure, Chronic* ; Lipid Peroxidation ; Malondialdehyde* ; Membranes ; Renal Dialysis* ; Superoxide Dismutase

No abstract available.
Humans

The role of the periosteum on osteointegration of Bio-Oss(R)(Geistlich, Wolhusen/Switzerland) was studied in rabbit calvarial defect. 12 New Zealand white male rabbits between 2.8 and 4 kg were included in this randomized, blinded, prospective study. Each rabbit was anesthetized with Ketamine HCl(5 mg/kg) and Xylazine HCl(1.5 ml/kg). An incision was made to the bony cranium and the periosteum was reflected. Using a 6-mm trephine bur(3i. USA), four 8-mm defects were created with copious irrigation. The defects were classified into barrier membrane(Tefgen(R), Lifecore Biomedical, Inc, U.S.A.) only group as a control, Bio-Oss(R) with barrier membrane group, Bio-Oss(R) with periosteum covering group, and Bio-Oss(R) without periosteum covering group. There were 2 rabbits in each group. The wound was closed with resorbable suture materials. Rabbits were sacrificed using phentobarbital(100 mg/kg) intravenously at 1, 2, and 4 weeks after surgery. The samples were fixed in 4% paraformaldehyde, and decalcified in hydrochloric acid decalcifying solution(Fisher Scientific, Tustin, CA) at 4degrees C for 2-4 weeks. It was embedded in paraffin and cut into 6 micrometer thickness. The sections were stained with H & E and observed by optical microscope. The results were as follows; 1. The periosteum played an important role in osteointegration of Bio-Oss(R) in bone defects. 2. When the periosteum remained intact and Bio-Oss(R) was placed on the defect, Bio-Oss(R) with periosteum covering has been incorporated into the newly formed bone from 2-week postoperatively. 3. When the periosteum was removed at the surgical procedure, invasion of connective tissue took place among the granules, and new bone formation was delayed compared to periosteum covering group. Therefore, when the bone grafting was performed with periosteal incision procedure to achieve tension-free suture, the integrity of the overlying periosteum should be maintained to avoid fibrous tissue ingrowth.
Bone Regeneration* ; Bone Transplantation ; Connective Tissue ; Humans ; Hydrochloric Acid ; Ketamine ; Male ; Membranes ; New Zealand ; Osteogenesis ; Paraffin ; Periosteum* ; Prospective Studies ; Rabbits ; Skull ; Sutures ; Wounds and Injuries ; Xylazine