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1.
Microvasc Res ; 136: 104165, 2021 07.
Article in English | MEDLINE | ID: mdl-33845105

ABSTRACT

Phototherapy has been tried for treating cardiovascular diseases. In particular, ultraviolet and blue visible lights were suggested to be useful due to their nitric oxide (NO)-production ability in the skin. However, the effects of blue light on the arterial contractility are controversial. Here, we hypothesized that appropriate protocol of blue laser can induce selective vasorelaxation by activating vasodilating signaling molecules in arteries. Using organ chamber arterial mechanics, NO assay, Matrigel assay, and microarray, we showed that a 200-Hz, 300-µs, 445-nm pulsed-laser (total energy of 600 mJ; spot size 4 mm) induced selective vasorelaxation, without vasocontraction in rat mesenteric arteries. The laser stimulation increased NO production in the cord blood-endothelial progenitor cells (CB-EPCs). Both the laser-induced vasorelaxation and NO production were inhibited by a non-selective, pan-NO synthase inhibitor, L-NG-Nitro arginine methyl ester. Microarray study in CB-EPCs suggested up-regulation of cryptochrome (CRY)2 as well as NO synthase (NOS)1 and NOSTRIN (NOS trafficking) by the laser. In conclusion, this study suggests that the 445-nm blue puled-laser can induce vasorelaxation possibly via the CRY photoreceptors and NOSs activation. The blue laser-therapy would be useful for treating systemic hypertension as well as improving local blood flow depending on the area of irradiation.


Subject(s)
Endothelial Progenitor Cells/radiation effects , Lasers , Low-Level Light Therapy/instrumentation , Mesenteric Arteries/radiation effects , Nitric Oxide Synthase/metabolism , Nitric Oxide/metabolism , Vasodilation/radiation effects , Animals , Cells, Cultured , Endothelial Progenitor Cells/enzymology , Enzyme Activation , Fetal Blood/cytology , Gene Expression Regulation , Humans , Male , Mesenteric Arteries/enzymology , Nitric Oxide Synthase/genetics , Rats, Sprague-Dawley , Signal Transduction
2.
Probl Radiac Med Radiobiol ; 25: 321-337, 2020 Dec.
Article in English, Ukrainian | MEDLINE | ID: mdl-33361844

ABSTRACT

OBJECTIVE: in the experiment, to investigate the effect of Quercetin on the NO-dependent reactions of isolated vessels involving endothelium and perivascular adipose tissue (PVAT) after a single X-ray irradiation of rats at a sublethal dose. In a clinical study, to investigate the effect of long-term use of Quercetin on the functional state of themicrovascular endothelium in the elderly patients with metabolic syndrome (MS). MATERIAL AND METHODS: Experimental studies were performed on vascular fragments obtained from adult male rats(7-8 months) of the control group, in animals exposed to a single R-irradiation at a dose of 7 Gy and animals irradiated in the same dose, which received Quercetin orally for 14 days three times a week based on 10 mg/kg bodyweight. Fragments of the thoracic aorta (TA) and mesenteric artery (MA) were cleaned of perivascular adipose tissue (PVAT-) or left uncleaned (PVAT+), and then were cut into rings (up to 2 mm). The amplitude of the contractionof the rings TA and MA under the influence of phenylephrine (PE, 3 x 10-6 M), the amplitude of the contraction of therings TA and MA in the presence of a competitive blocker of NO-synthase methyl ester of N-nitro-L-arginine(L-NAME, 10-5 M), the amplitude of relaxation of the rings TA and MA in the presence of N-acetylcysteine (NAC, 10-4 M)were measured. The clinical study examined 110 patients with MS criteria in accordance with ATP III (2001).Patients in the main group for 3 months received Quercetin from the same manufacturer, 80 mg three times a day,patients in the control group received placebo. RESULTS: Single R-irradiation disrupts the regulation of the contractile function of TA and MA, which is evidenced bychanges in the contractile reactions of isolated fragments of these vessels as a response to the action of vasoactivecompounds. Course use of Quercetin in irradiated rats leads to the normalization of contractile and dilatory vascular responses due to partial correction of NO metabolism in the endothelium and PVAT. For the majority of patients(69 %) who received Quercetin, a post-occlusive hyperemia test showed a statistically significant increase of maximal volumetric velocity of the skin blood flow rate and duration of the recovery period to the baseline, which indicates about improvement of vasomotor vascular endothelial function. CONCLUSIONS: Course use of Quercetin improves the functional state of the microvascular endothelium among theelderly people with MS, normalizes contractile and dilatory vascular responses in irradiated rats due to partial correction of NO metabolism in the endothelium and PVAT.


Subject(s)
Aorta, Thoracic/drug effects , Blood Flow Velocity/drug effects , Endothelium, Vascular/drug effects , Mesenteric Arteries/drug effects , Metabolic Syndrome/drug therapy , Quercetin/pharmacology , Acetylcysteine/pharmacology , Adipose Tissue/drug effects , Adipose Tissue/metabolism , Adipose Tissue/radiation effects , Aged , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Animals , Aorta, Thoracic/metabolism , Aorta, Thoracic/radiation effects , Aspirin/therapeutic use , Blood Flow Velocity/physiology , Blood Flow Velocity/radiation effects , Case-Control Studies , Endothelium, Vascular/metabolism , Endothelium, Vascular/radiation effects , Female , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Male , Mesenteric Arteries/metabolism , Mesenteric Arteries/radiation effects , Metabolic Syndrome/metabolism , Metabolic Syndrome/pathology , Middle Aged , NG-Nitroarginine Methyl Ester/pharmacology , Phenylephrine/pharmacology , Rats , Tissue Culture Techniques , X-Rays
3.
Biochem Pharmacol ; 180: 114102, 2020 10.
Article in English | MEDLINE | ID: mdl-32562786

ABSTRACT

Radiation enteritis (RE) is a common side effect after radiotherapy for abdominal cancer. RE pathogenesis is complicated, with no drugs available for prevention or treatments. Intestinal ischemia is a key factor in the occurrence and development of enteritis. The effect of ionizing radiation (IR) on intestinal ischemia is unknown. Deficiency of tetrahydrobiopterin (BH4) produced by GTP-cyclohydrolase 1 (Gch1) is important in ischemic diseases. This study focused on the relationship of Gch1/BH4 between intestinal ischemia in radiation enteritis. BH4 levels were analyzed by high-performance liquid chromatography in humans and rats after radiotherapy. Intestinal blood perfusion was measured by laser doppler flow imaging. Vascular ring tests determined the diastolic functions of rat mesenteric arteries. Gene, protein, and immunohistochemical staining experiments and inhibitor interventions were used to investigate Gch1 and endothelial NOS (eNOS) in rat mesenteric arteries and endothelial cells. The results showed that IR decreased BH4 levels in patients and rats after radiotherapy and decreased intestinal blood perfusion in rats. The degree of change in intestinal ischemia was consistent with intestinal villus injury. Gch1 mRNA and protein levels and nitric oxide (NO) production significantly decreased, while eNOS uncoupling in arterial and vascular endothelial cells strongly increased. BH4 supplementation improved eNOS uncoupling and NO levels in vascular endothelia after IR. The results of this study showed that downregulation of Gch1 in intestinal blood vessels after IR is an important target in RE. BH4 supplementation may prevent intestinal ischemia and improve vascular endothelial function after IR. These findings have clinical significance for the prevention and treatment of RE.


Subject(s)
Enteritis/prevention & control , GTP Cyclohydrolase/genetics , Intestines/blood supply , Phenylketonurias/blood , Radiation Injuries/prevention & control , Radiotherapy/adverse effects , Aged , Aged, 80 and over , Animals , Biopterins/analogs & derivatives , Biopterins/pharmacology , Down-Regulation , Endothelium, Vascular/drug effects , Endothelium, Vascular/radiation effects , Enteritis/blood , Enteritis/genetics , Enteritis/pathology , Female , GTP Cyclohydrolase/antagonists & inhibitors , Human Umbilical Vein Endothelial Cells , Humans , Male , Mesenteric Arteries/drug effects , Mesenteric Arteries/radiation effects , Middle Aged , Nitric Oxide Synthase Type III/metabolism , Phenylketonurias/etiology , Radiation Injuries/blood , Radiation Injuries/genetics , Radiation Injuries/pathology , Radiation Injuries, Experimental/blood , Radiation Injuries, Experimental/genetics , Radiation Injuries, Experimental/prevention & control , Rats , Rats, Sprague-Dawley , Vasodilation/drug effects , Vasodilation/radiation effects
5.
J Pharmacol Exp Ther ; 311(1): 411-9, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15205450

ABSTRACT

The present study investigated the effects of different classes of cannabinoid (CB) receptor ligands on sensory neurotransmission in the rat isolated mesenteric arterial bed. Electrical field stimulation of the mesenteric bed evoked frequency-dependent vasorelaxation due to the activation of capsaicin-sensitive sensory nerves and release of calcitonin gene-related peptide (CGRP). The CB(1)/CB(2) cannabinoid agonists WIN55,212 [(R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl)pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl]-1-naphthalenylmethanone] and CP55,940 [(-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4-(3-hydroxypropyl) cyclohexanol] (0.01-1 microM) attenuated sensory neurogenic relaxation in a concentration-dependent manner. At 0.1 microM, WIN55,212 and CP55,940 were largely ineffective in the presence of the CB(1) antagonists SR141716A [N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichloro phenyl)-4-methyl-3-pyrazole-carboxamide] and LY320135 [[6-methoxy-2-(4-methoxyphenyl)benzo[b]-thien-3-yl][4-cyanophenyl] methanone] (1 microM), but their inhibitory actions remained in the presence of the CB(2)-selective antagonist SR144528 [N-[1S)-endo-1,3,3,-trimetyl bicyclo [2.2.1]heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide] (1 microM). The CB(1)/CB(2) agonist Delta(9)-tetrahydrocannabinol (THC) (1 microM) attenuated sensory neurogenic relaxations, as did the CB(2) agonist JWH-015 [(2-methyl-1-propyl-1H-indol-3-yl)-1-naphthalenylmethanone]. The inhibitory actions of both THC and JWH-015 were still evident in the presence of SR141716A (1 microM) and SR144528 (1 microM). None of the cannabinoid agonists investigated had an effect on vasorelaxation elicited by exogenous CGRP, indicating a prejunctional mechanism. These data demonstrate that different classes of cannabinoid agonists attenuate sensory neurotransmission via a prejunctional site and provide evidence for mediation by a CB(1) and/or a non-CB(1)/CB(2) receptor.


Subject(s)
Cannabinoids/pharmacology , Electric Stimulation , Mesenteric Arteries/radiation effects , Vasodilation/radiation effects , Animals , Benzofurans/pharmacology , Benzoxazines , Calcitonin Gene-Related Peptide/pharmacology , Camphanes/pharmacology , Capsaicin/pharmacology , Cyclohexanols/pharmacology , Cyclohexanols/toxicity , Dronabinol/pharmacology , Indoles/pharmacology , Male , Mesenteric Arteries/drug effects , Mesenteric Arteries/physiology , Morpholines/pharmacology , Naphthalenes/pharmacology , Piperidines/pharmacology , Pyrazoles/pharmacology , Rats , Rats, Wistar , Receptors, Cannabinoid/physiology , Rimonabant , Vasodilation/drug effects
6.
Lasers Surg Med ; 28(5): 461-8, 2001.
Article in English | MEDLINE | ID: mdl-11413559

ABSTRACT

BACKGROUND AND OBJECTIVE: To study the impact of laser pulses on animal microvasculature as a model for laser treatment of port wine stains. STUDY DESIGN/MATERIALS AND METHODS: Rat mesenteric blood vessels were irradiated with a laser pulse (585 nm, 0.2-0.6 ms pulse duration, 0.5-30 J/cm(2) radiant exposure). Video microscopy was used to assess vessel dilation, formation of intravascular thrombi, bubble formation, and vessel rupture. Changes in reflection during a laser pulse were measured by simultaneously recording the temporal behavior of the incident and reflected signals. RESULTS: A threshold radiant exposure of approximately 3 J/cm(2) was found for changes in optical properties of blood in vivo, confirming previous in vitro results. Often, laser exposure induced a significant increase in vessel diameter, up to three times the initial diameter for venules and four times for arterioles, within 200 ms after laser exposure. Arterioles were more likely to dilate than venules. Sometimes, immediately after the pulse, round structures, interpreted as being gas bubbles, were seen within the vessel lumen. CONCLUSIONS: A variety of phenomena can occur when blood vessels of sizes comparable to those in port wine stains are irradiated with laser pulses as used in port wine stain treatment. Thrombus formation and vessel rupture have been described before from histological sections of laser-irradiated port wine stains. However, vessel dilation and formation of non-transient gas bubbles as found in this study have not been described before.


Subject(s)
Lasers , Mesenteric Arteries/radiation effects , Mesenteric Veins/radiation effects , Port-Wine Stain/surgery , Animals , In Vitro Techniques , Laser Therapy , Mesenteric Arteries/pathology , Mesenteric Veins/pathology , Rats , Thrombosis/etiology
7.
Thromb Res ; 100(3): 167-77, 2000 Nov 01.
Article in English | MEDLINE | ID: mdl-11108904

ABSTRACT

Controversy still exists about the pro- or antithrombotic side effects of contrast media used in daily medical practice. Recent reports have shown that various contrast media, including ionic compounds, have deleterious prothrombotic actions. A new evaluation of these adverse side effects is reported here, with the study of the dose-effect relationship. Two ionic (ioxaglate and diatrizoate) and two non-ionic contrast media (iopamidol and iohexol) were studied. Experiments were done on 22 groups of 5 Wistar male rats each, using a Laser Argon-induced thrombosis model in mesenteric microvessels. Three parameters were studied: the number of laser beams needed to induce platelet thrombus formation, the number of emboli, and the duration of embolization. Platelet count and platelet aggregation also were determined. Iopamidol and iohexol induced a significant rise in both the number of emboli and the duration of embolization in mesenteric microvessels at doses up to 1 mL/kg. Ioxaglate and diatrizoate also significantly increased these parameters at doses up to 2 mL/kg. All the products tested decreased platelet count, inducing a -17 to -30% variation from control values. Diatrizoate and ioxaglate inhibited platelet aggregation, while iopamidol and Iohexol behaved as activators. All non-ionic, and to a lesser extent, all ionic contrast media demonstrated prothrombotic properties.


Subject(s)
Contrast Media/adverse effects , Thrombophilia/chemically induced , Thrombosis/chemically induced , Animals , Diatrizoate/adverse effects , Disease Models, Animal , Dose-Response Relationship, Drug , Iohexol/pharmacology , Iopamidol/pharmacology , Ioxaglic Acid/adverse effects , Lasers/adverse effects , Leukocyte Count , Male , Mannitol/pharmacology , Mesenteric Arteries/drug effects , Mesenteric Arteries/radiation effects , Microcirculation/drug effects , Microcirculation/radiation effects , Platelet Aggregation/drug effects , Rats , Rats, Wistar , Sodium Chloride/pharmacology
10.
Nihon Geka Gakkai Zasshi ; 94(5): 494-500, 1993 May.
Article in Japanese | MEDLINE | ID: mdl-8332123

ABSTRACT

For the treatment of pancreatic head cancer, pancreatoduodenectomy is followed by the intraoperative radiation therapy (IORT). The present dose adopted ranged 20 to 30 Gy, however the dose is believed to be insufficient for local control of adenocarcinoma cells. In this study, high dose IORT was performed using rabbit, so histological and nutritional changes were evaluated. Rabbits were divided in three groups; 30 Gy, 50 Gy, 80 Gy. The radiation was performed with electrons focusing base of cranial mesenteric artery (SMA in human). The rabbits were sacrificed at intervals ranging from immediately after to 4 weeks following irradiation. The earliest evidence of histological changes was the loss of endothel, although it was repaired within 1 week. Fragmentation and reduplication of internal elastic lamina were observed after 1 week, however the degree was not dose dependent. Damages of the media was observed in 50 and 80 Gy groups. That is, focal degeneration of smooth muscle cell was demonstrated in 50 Gy group and medial necrosis in 80 Gy group. Degeneration of ganglion cells was observed and its severity was dose dependent. In 80 Gy group, diarrhea occurred more frequently compared with the other groups and body weight loss couldn't recover within 4 weeks. It is concluded that, since necrosis of aortic media and marked degeneration of ganglion cells are inevitable in 80 Gy group, IORT dose should be increased within 50 Gy.


Subject(s)
Intraoperative Care , Pancreatic Neoplasms/radiotherapy , Pancreatic Neoplasms/surgery , Animals , Aorta, Abdominal/pathology , Aorta, Abdominal/radiation effects , Combined Modality Therapy , Ganglia/physiology , Mesenteric Arteries/pathology , Mesenteric Arteries/radiation effects , Necrosis , Nerve Degeneration/radiation effects , Pancreatic Neoplasms/pathology , Rabbits , Radiotherapy Dosage
11.
Doc Ophthalmol ; 79(3): 221-39, 1992.
Article in English | MEDLINE | ID: mdl-1600840

ABSTRACT

Haemostasis was effected in vessels of melanin-rich (MR: choroid) and melanin-free (MF: mesentery) rabbit tissue irradiated with a cw-Nd:YAG laser. The following parameters were employed: - pulse duration: 200 ms (MR) and 100 ms (MF); focal spot diameter: 200 microns (MR) and 80 microns (MF); pulse energies: 100-250 mJ (MR) and 0.5-1 J (MF); irradiances: 1.6-4.0 kW cm-2 (MR) and 1-2 x 10(2) kW cm-2 (MF). In melanin-rich tissue, laser energy is absorbed principally by melanin granules contained within the stromal melanocytes. The heat generated in these structures radiates into the surrounding tissue where it is dissipated. The damage thus incurred by the endothelium of blood vessels encompassed within this field triggers the haemostatic mechanism whereby blood flow is arrested. This effect is realized by the formation of an occluding plug of platelets, which is stabilized by the deposition of fibrin, particularly in capillaries, and to a lesser degree in larger vessels of the vascular lamina. In melanin-free tissue, haemoglobin serves as the primary site of energy absorption, which is thus shifted from the stroma to the vessel lumen. Irradiation of vessels in such tissue leads to thermocoagulation of plasma proteins and consequent stasis of blood flow.


Subject(s)
Choroid/blood supply , Hemostasis/radiation effects , Light Coagulation , Melanins/radiation effects , Mesenteric Arteries/radiation effects , Animals , Blood Coagulation/physiology , Choroid/radiation effects , Choroid/ultrastructure , Endothelium, Vascular/radiation effects , Endothelium, Vascular/ultrastructure , Melanins/metabolism , Mesenteric Arteries/ultrastructure , Rabbits
12.
Thromb Haemost ; 65(1): 87-95, 1991 Jan 23.
Article in English | MEDLINE | ID: mdl-2024243

ABSTRACT

cw-Nd:YAG laser radiation was effective in producing blood flow stasis within arteries (35-40 microns in diameter) of pigmented rabbit mesentery (beam spot size: 80 microns; fluence: 2 x 10(4) J cm-2) and choroid (beam spot size: 200 microns; fluence: 6 x 10(2) J cm-2). However, the mechanism by which this was achieved differed in each case, and depended upon the energy absorbing structures present in the irradiated tissue. In non-pigmented tissue, such as the mesentery, haemoglobin represents the primary absorption centre, and the temperature attained within the vessel lumen (as inferred from morphological changes) is sufficient to denature plasma proteins, in particular fibrinogen, which consequently occlude the vessel lumen and arrest bleeding. In pigmented tissue, such as the choroid, melanocyte granules represent the primary absorption centre, which is thus shifted from the vessel lumen to the stroma. The temperature rise achieved within the vessel lumen is consequently lower, as evidenced by the absence of plasma protein denaturation. Blood flow stasis nonetheless occurs, but is triggered according to the normal haemostatic mechanism.


Subject(s)
Choroid/blood supply , Hemostasis/radiation effects , Laser Therapy , Mesenteric Arteries/radiation effects , Animals , Arteries/radiation effects , Arteries/ultrastructure , Capillaries/radiation effects , Capillaries/ultrastructure , Mesenteric Arteries/ultrastructure , Rabbits , Skin Pigmentation/physiology
13.
Biochem Biophys Res Commun ; 169(1): 129-35, 1990 May 31.
Article in English | MEDLINE | ID: mdl-1972015

ABSTRACT

It was demonstrated that precontracted strips from different bovine mesenteric arteries showed variation in sensitivity to ultraviolet radiation (366 nm). Some strips relaxed when they were exposed to ultraviolet light, others showed no sensitivity at all and, finally, some showed contraction. However, all arteries relaxed when they were irradiated with UV-light in the presence of 10 microM NaNO2. Ultraviolet radiation (366 nm) increased the activity of guanylate cyclase in crude homogenate from bovine mesenteric arteries by about 20-fold in the presence of NaNO2, while UV-light in the absence of sodium nitrite had no effect on the guanylate cyclase activation. These results support the notion that nitrite may be essential for vascular smooth muscle relaxation by UV-light, possibly through the release of nitric oxide.


Subject(s)
Guanylate Cyclase/metabolism , Muscle, Smooth, Vascular/radiation effects , Nitrites/pharmacology , Sodium Nitrite/pharmacology , Ultraviolet Rays , Animals , Cattle , Enzyme Activation/drug effects , Enzyme Activation/radiation effects , Mesenteric Arteries/drug effects , Mesenteric Arteries/enzymology , Mesenteric Arteries/radiation effects , Muscle Relaxation/drug effects , Muscle Relaxation/radiation effects , Muscle, Smooth, Vascular/drug effects , Muscle, Smooth, Vascular/enzymology , Phenylephrine/pharmacology
14.
Biull Eksp Biol Med ; 105(3): 279-81, 1988 Mar.
Article in Russian | MEDLINE | ID: mdl-3349166

ABSTRACT

Serotonin content and accumulation in platelets and its release from them, as well as changes in thrombus formation in mesenteric arterioles and venules of the small intestine have been investigated in control rats and rats with spontaneous hypertension (SHR). Serotonin accumulation in platelets was determined upon its incubation with platelets. Disodium ADP salt was used as an inductor of release. Laser-induced thrombosis was caused by microvessels exposure to impulse laser irradiation. The control animals revealed a significant difference between the initial serotonin platelet level and serotonin level upon incubation and release; in values, the values of basic thrombus-forming parameters were higher than in arterioles. In SHR there is a decrease in biogenic amine content in platelets, a depression in its accumulation and release, an increase in the time of thrombus growth, its size up to the separation of the first embolus and its length along the vascular wall. It is concluded that spontaneous hypertension is characterized by decreased functional activity of platelets and depressed resistance of arterioles and venules to thrombus formation.


Subject(s)
Blood Platelets/metabolism , Hemostasis , Hypertension/blood , Serotonin/blood , Animals , Hypertension/complications , Lasers/adverse effects , Male , Mesenteric Arteries/radiation effects , Mesenteric Vascular Occlusion/blood , Mesenteric Vascular Occlusion/etiology , Mesenteric Veins/radiation effects , Microcirculation/metabolism , Microcirculation/radiation effects , Rats , Rats, Inbred SHR , Thrombosis/blood , Thrombosis/etiology
15.
Article in English | MEDLINE | ID: mdl-2876013

ABSTRACT

Strips of bovine mesenteric arteries, brought to sustained contraction by addition of 3.0 microM phenylephrine, relaxed during exposure to shortwave light. The action spectrum of the photorelaxation was characterized by most effectiveness of relaxation in the range of 360 to 400 nm; on the contrary, shortwave light of 280 to 300 nm increased the tension. The photo-induced relaxation was accompanied by an increase in the cGMP level, measured 30 sec after the onset of radiation, and the action spectrum of the increase in cGMP seemed to coincide fairly well with the action spectrum of relaxation. Both the increase in cGMP and relaxation in response to increasing light intensity at 400 nm fitted the rectangular hyperbolic equation. The K values (the intensity which gave half maximal response) for cGMP increase and relaxation, respectively, obtained by non-linear least square regression analysis, were found to assume very close values (1.3 mW/cm2 for cGMP increase and 1.5 mW/cm2 for relaxation). The action spectrum of the crude soluble guanylate cyclase (GC) activity displayed a peak around 400 nm. Our results suggest that there is a close association between photo-induced increase in cGMP and relaxation, probably as a result of interaction between shortwave light and the heme moiety of GC.


Subject(s)
Cyclic GMP/radiation effects , Muscle Contraction/radiation effects , Muscle Relaxation/radiation effects , Muscle, Smooth, Vascular/radiation effects , 3',5'-Cyclic-GMP Phosphodiesterases/radiation effects , Animals , Cattle , Cyclic GMP/metabolism , Enzyme Activation/radiation effects , Guanylate Cyclase/radiation effects , In Vitro Techniques , Light , Mesenteric Arteries/physiology , Mesenteric Arteries/radiation effects , Muscle, Smooth, Vascular/physiology , Spectrophotometry , Ultraviolet Rays
16.
Life Sci ; 34(16): 1555-63, 1984 Apr 16.
Article in English | MEDLINE | ID: mdl-6144030

ABSTRACT

Strips of bovine mesenteric arteries brought to sustained contraction by the addition of 3.0 microM phenylephrine relaxed when exposed to ultraviolet radiation (366 nm). The relaxation was reversible and associated with a rapid increase in the cGMP content. After termination of the radiation the cGMP level rapidly decreased below the basal level. The crude soluble guanylate cyclase from the artery was stimulated about 8-fold by ultraviolet radiation (366 nm). Neither the cGMP-phosphodiesterase activity nor the cAMP level were found to be changed during irradiation. The ultraviolet light-induced relaxation was not dependent on an intact intimal surface. Furthermore, the relaxing effect was found to be enhanced and accompanied by a larger increase of the cGMP level in nitroglycerin-tolerant arteries. The present results show that the ultraviolet light-induced relaxation in bovine mesenteric arteries is associated with a rapid increase in the cGMP content and that ultraviolet light and nitrocompounds may exert their relaxing actions through a common substance.


Subject(s)
Cyclic GMP/metabolism , Muscle, Smooth, Vascular/radiation effects , Ultraviolet Rays , 3',5'-Cyclic-GMP Phosphodiesterases/metabolism , Animals , Cattle , Guanylate Cyclase/metabolism , In Vitro Techniques , Mesenteric Arteries/metabolism , Mesenteric Arteries/radiation effects , Muscle Contraction/radiation effects , Muscle, Smooth, Vascular/metabolism
17.
Arch Fr Pediatr ; 41(2): 135-8, 1984 Feb.
Article in French | MEDLINE | ID: mdl-6326705

ABSTRACT

Pancreatic, hepatic and intestinal troubles occurred in a 8 year-old acrogeria girl who was treated for Wilm's tumor by cobalt therapy at 2 1/2 years. Complete obstruction of the coeliac trunk and proximal superior mesenteric artery was shown, associated with hypoplasia of the abdominal aorta and its collaterals in the irradiated areas. Acrogeria might enhance the toxic effects of radiotherapy on vessels.


Subject(s)
Celiac Artery/radiation effects , Kidney Neoplasms/radiotherapy , Mesenteric Vascular Occlusion/etiology , Radiation Injuries/etiology , Wilms Tumor/radiotherapy , Child , Child, Preschool , Digestive System Diseases/etiology , Female , Humans , Mesenteric Arteries/radiation effects , Progeria/complications , Vascular Diseases/etiology
18.
Strahlentherapie ; 157(3): 208-12, 1981 Mar.
Article in English | MEDLINE | ID: mdl-6111139

ABSTRACT

A beta-blocker, propranolol, was infused to control and irradiated rats the 1st and 3rd day after 2-kR X-ray irradiation. Blood pressure and mesenteric blood flow were recorded during infusion of biogenic amines (noradrenaline, dopamine, serotonin, acetylcholine and histamine). After beta-blockade, there was intensified increase in pressure and decrease in flow with increased overshoot after infusion of noradrenaline, no effect on the increase in pressure and flow after dopamine, but an enhanced increase in pressure and decrease in flow after serotonin. No effect on the decrease in pressure and flow was seen after acetylcholine, and a greater decrease in pressure and flow, after histamine. Irradiation altered the vascular reactivity, mainly for noradrenaline, serotonin and histamine.


Subject(s)
Adrenergic beta-Antagonists/pharmacology , Blood Pressure/drug effects , Mesenteric Arteries/drug effects , Propranolol/pharmacology , Radiation Effects , Acetylcholine/pharmacology , Animals , Dopamine/pharmacology , Histamine/pharmacology , Mesenteric Arteries/radiation effects , Norepinephrine/pharmacology , Rats , Regional Blood Flow/drug effects , Serotonin/pharmacology
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