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Obara K, Yoshioka K, Tanaka Y. [Platelet-activating Factor (PAF) in Urinary Bladder Smooth Muscle (UBSM): Its Novel Role as a Potential Inducer of Detrusor Overactivity and the Mechanisms Underlying Its Effects in Enhancing UBSM Mechanical Activities]. YAKUGAKU ZASSHI 2024; 144:997-1007. [PMID: 39496432 DOI: 10.1248/yakushi.24-00136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2024]
Abstract
Platelet-activating factor (PAF), a phospholipid mediator, was discovered in 1972 as an inducer of platelet aggregation. Subsequent studies have revealed that PAF has a variety of biological functions, such as its role as a potent proinflammatory mediator. Additionally, PAF regulates the contractile functions of various types of smooth muscle (SM), such as the (1) endothelium-dependent relaxation of vascular SM; (2) contraction and epithelium-dependent relaxation of airway SM; (3) contraction of gastrointestinal SM; and (4) contraction of uterine SM, which occurs more strongly in pregnant females. PAF is produced in platelets, monocytes, neutrophils, and macrophages, which are cells related to thrombus formation and inflammation/immune responses. Furthermore, PAF is produced in various other cells throughout the body. Interestingly, recent studies have focused on the urinary bladder (UB) as a PAF-producing organ since the accumulation of this phospholipid is enhanced in patients with bladder cancer and interstitial cystitis/bladder pain syndrome, especially those who smoke. Therefore, in UB tissue, PAF may play a substantial role as an inducer or enhancer of cancers and inflammatory diseases. However, the effects of PAF on the immediate mechanical activities of UBSM have not been investigated to date. In this regard, we recently discovered that PAF strongly enhances mechanical activities (muscle tone and spontaneous contractile activity) in UBSM tissues isolated from guinea pigs and mice. In this review article, we present our data on these PAF effects together with the possible underlying mechanisms. We also discuss the potential pathophysiological roles of this phospholipid in UB diseases and disorders.
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Affiliation(s)
- Keisuke Obara
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Kento Yoshioka
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
| | - Yoshio Tanaka
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, Toho University
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Thongprayoon C, Cheungpasitporn W, Chewcharat A, Mao MA, Thirunavukkarasu S, Kashani KB. Impacts of admission serum albumin levels on short-term and long-term mortality in hospitalized patients. QJM 2020; 113:393-398. [PMID: 31747010 DOI: 10.1093/qjmed/hcz305] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 10/19/2019] [Indexed: 12/14/2022] Open
Abstract
AIM The aim of this study is to assess the association between admission serum albumin and short- and long-term mortality in all hospitalized patients. DESIGN A single-center cohort study. METHODS A retrospective cohort of all adult hospitalized patients at a tertiary referral hospital between January 2009 and December 2013 were analysed. Admission serum albumin was stratified into six groups: ≤2.4, 2.5-2.9, 3.0-3.4, 3.5-3.9, 4.0-4.4 and ≥4.5 g/dl. The outcomes of interest were in-hospital mortality, length of hospital stay and 1-year mortality. Serum albumin of 4-4.4 g/dl was selected as a reference group for outcome comparison. RESULTS A total of 14 075 patients were studied. Admission serum albumin of ≥4.5 g/dl had the lowest in-hospital and 1-year mortality with progressively increased in-hospital mortality observed with decreased admission serum albumin. In adjusted analysis, compared with serum albumin of 4.0-4.4 g/dl, serum albumin of ≤2.4, 2.5-2.9, 3.0-3.4 and 3.5-3.9 were significantly associated with increased in-hospital and 1-year mortality. In contrast, serum albumin of ≥4.5 g/dl was significantly associated with lower 1-year mortality but not in-hospital mortality. Admission serum albumin <4.0 g/dl was significantly associated with a prolonged hospital stay, while admission serum albumin of ≥4.5 g/dl was significantly associated with shorter hospital stay, compared with serum albumin of 4.0-4.4 g/dl. CONCLUSION Low albumin level at admission was progressively associated with increased short- and long-term mortality in all hospitalized patients even when albumin level was considered in normal range.
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Affiliation(s)
- C Thongprayoon
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Rochester, MN 55905
| | - W Cheungpasitporn
- Division of Nephrology, Department of Internal Medicine, University of Mississippi Medical Center, Jackson, MS 39216
| | - A Chewcharat
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Rochester, MN 55905
| | - M A Mao
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Jacksonville, FL 32224
| | - S Thirunavukkarasu
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Rochester, MN 55905
| | - K B Kashani
- Division of Nephrology and Hypertension, Department of Medicine, Mayo Clinic, Rochester, MN 55905
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Mayo Clinic, Rochester, MN 55905, USA
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Shin KH, Han SB. Early postoperative hypoalbuminemia is a risk factor for postoperative acute kidney injury following hip fracture surgery. Injury 2018; 49:1572-1576. [PMID: 29908852 DOI: 10.1016/j.injury.2018.05.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 05/02/2018] [Indexed: 02/02/2023]
Abstract
INTRODUCTION Acute kidney injury (AKI) is a common and serious complication after hip fracture surgery in older adults. Hypoalbuminemia is a known independent risk factor for AKI. However, few studies have investigated the relationship between early postoperative hypoalbuminemia and AKI after hip fracture surgery. Therefore, we sought to determine the incidence of and risk factors for AKI and the effects of early postoperative hypoalbuminemia on AKI incidence after surgery for hip fractures, especially intertrochanteric fractures of the proximal femur. PATIENTS AND METHODS In this retrospective cohort study from a single center, we reviewed the medical records of 481 consecutive patients (>60 years) who underwent surgery for intertrochanteric fracture of the proximal femur. Multiple logistic regression was performed to identify independent risk factors for AKI. After determining the cut-off value of the minimal level of postoperative serum albumin during the first two postoperative days, we divided the patients into two groups: group 1 included 251 patients whose minimal early postoperative serum albumin level was <2.9 g/dL during the first two postoperative days; and group 2 included 230 patients whose minimal early postoperative serum albumin level was ≥2.9 g/dL. The incidence of AKI was analyzed using inverse probability of treatment weighting (IPTW), propensity score matching (PSM), and propensity score matching weighting (PSMW) analyses. RESULTS The incidence of AKI, defined based on the Kidney Disease Improving Global Outcomes criteria, was 11.8% (n = 57). Chronic kidney disease and the minimal early postoperative serum albumin level <2.9 g/dL at any point during the first two postoperative days were independent risk factors for AKI. The IPTW, PSM, and PSMW analyses comparing the incidence of AKI between the two groups revealed that the minimal early postoperative serum albumin level <2.9 g/dL was significantly associated with AKI development (P < 0.001, P = 0.025, and P = 0.011, respectively). CONCLUSION The incidence of postoperative AKI was 11.8%. Our findings demonstrate that early postoperative hypoalbuminemia is an independent risk factor for AKI in patients undergoing surgery for intertrochanteric fracture of the proximal femur.
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Affiliation(s)
- Kyun-Ho Shin
- Department of Orthopaedic Surgery, Anam Hospital, Korea University College of Medicine, Seoul, South Korea
| | - Seung-Beom Han
- Department of Orthopaedic Surgery, Anam Hospital, Korea University College of Medicine, Seoul, South Korea.
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U-shape association of serum albumin level and acute kidney injury risk in hospitalized patients. PLoS One 2018; 13:e0199153. [PMID: 29927987 PMCID: PMC6013099 DOI: 10.1371/journal.pone.0199153] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 06/03/2018] [Indexed: 12/31/2022] Open
Abstract
Background While an association between hypoalbuminemia and increased risk of acute kidney injury (AKI) is well-established, the risk of AKI development and its severity among patients with elevated serum albumin is unclear. The aim of this study was to evaluate the risk of AKI in hospitalized patients stratified by various admission serum albumin levels. Methods This single-center retrospective study was conducted at a tertiary referral hospital. All adult hospitalized patients who had admission albumin levels available between January 2009 and December 2013 were enrolled. Admission albumin was categorized based on its distribution into six groups (≤2.4, 2.5–2.9, 3.0–3.4, 3.5–3.9, 4.0–4.4, and ≥4.5 mg/dL). The primary outcome was the incidence of hospital-acquired AKI (HAKI). Logistic regression analysis was performed to obtain the odds ratio of AKI for various admission albumin strata using the albumin 3.5 to 3.9 mg/dL (lowest incidence of AKI) as the reference group. Results Of the total 9,552 studied patients, HAKI occurred in 1,556 (16.3%) patients. The incidence of HAKI among patients with admission albumin ≤2.4, 2.5–2.9, 3.0–3.4, 3.5–3.9, 4.0–4.4, and ≥4.5 mg/dL was 18.3%, 14.3%, 15.5%, 14.2%, 16.7%, and 26.0%, respectively. After adjusting for potential confounders, admission serum albumin levels ≤2.4 and ≥4.5 mg/dL were associated with an increased risk of HAKI with odds ratios of 1.52 (95% CI 1.18–1.94) and 2.16 (95% CI 1.74–2.69), respectively. While stage 1 HAKI was significantly more frequent among patients with admission albumin ≥4.5 mg/dL (23.0% vs. 11.6%, P<0.001), incidence of stage 3 HAKI was higher in those with albumin ≤2.4 mg/dL (2.8% vs 0.3%, P<0.001). Conclusion Admission serum albumin levels ≤2.4 and ≥4.5 mg/dL were associated with an increased risk for HAKI. Patients with admission albumin ≥4.5 mg/dL had HAKI with a lower intensity when compared with those who had admission albumin levels ≤2.4 mg/dL.
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Yu MY, Lee SW, Baek SH, Na KY, Chae DW, Chin HJ, Kim S. Hypoalbuminemia at admission predicts the development of acute kidney injury in hospitalized patients: A retrospective cohort study. PLoS One 2017; 12:e0180750. [PMID: 28723973 PMCID: PMC5516984 DOI: 10.1371/journal.pone.0180750] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 06/20/2017] [Indexed: 02/03/2023] Open
Abstract
Background Development of acute kidney injury (AKI) is common and is associated with poor outcomes. We aimed to determine whether hypoalbuminemia (HA) at admission could be a risk factor for the development of AKI and mortality in hospitalized patients. Methods We enrolled patients who were admitted to Seoul National University Bundang Hospital from January 2013 to December 2013. HA at admission was defined as a serum albumin level < 3.4 mg/dL measured within two days after admission. AKI was defined as an increase in the serum creatinine level by ≥0.3 mg/dL or ≥1.5 times of the baseline value during the hospital stay. Results A total of 19,472 patients were enrolled and divided into HA and normoalbuminemia (NA) groups at admission. The incidence of AKI was 10.7% (340/3179) in the HA group and 4.1% (662/16293) in the NA group (adjusted odds ratio [OR], 1.243; 95% confidence interval [CI], 1.069–1.445; P = 0.005). The hazard ratios for the 30-day, 90-day, and 1-year mortality were 1.873 (95% CI, 1.383–2.537; P < 0.001), 1.710 (95% CI, 1.410–2.072; P < 0.001), and 1.372 (95% CI, 1.214–1.551; P < 0.001), compared to the NA group. In patients with AKI, albumin replacement improved renal recovery (OR, 2.605; 95% CI, 1.450–4.681; P = 0.001). The mortality rate was not different according to albumin replacement. Conclusions HA is associated with the development of AKI and high mortality in hospitalized patients. Replacement of albumin after the development of AKI may contribute to renal recovery. Further clinical trials are warranted.
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Affiliation(s)
- Mi-Yeon Yu
- Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea
| | - Sung Woo Lee
- Department of Internal Medicine, Eulji General Hospital, Seoul, Korea
| | - Seon Ha Baek
- Department of Internal Medicine, Hallym University Dongtan Sacred Heart Hospital, Gyeonggi-do, Korea
| | - Ki Young Na
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Dong-Wan Chae
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Ho Jun Chin
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
| | - Sejoong Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
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Wiedermann CJ, Dunzendorfer S, Gaioni LU, Zaraca F, Joannidis M. Hyperoncotic colloids and acute kidney injury: a meta-analysis of randomized trials. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2010; 14:R191. [PMID: 21029460 PMCID: PMC3219298 DOI: 10.1186/cc9308] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 10/15/2010] [Accepted: 10/28/2010] [Indexed: 02/06/2023]
Abstract
Introduction It has been hypothesized that hyperoncotic colloids might contribute to acute kidney injury (AKI). However, the validity of this hypothesis remains unclear. Methods A meta-analysis was conducted of randomized controlled trials evaluating AKI after infusion of hyperoncotic albumin and hydroxyethyl starch (HES) solutions. Mortality was a secondary endpoint. Eligible trials were sought by multiple methods, and the pooled odds ratios (OR) for AKI and death and 95% confidence intervals (CI) were computed under a random effects model. Results Eleven randomized trials with a total of 1220 patients were included: 7 evaluating hyperoncotic albumin and 4 hyperoncotic HES. Clinical indications were ascites, surgery, sepsis and spontaneous bacterial peritonitis. Hyperoncotic albumin decreased the odds of AKI by 76% (OR, 0.24; CI, 0.12-0.48; P < 0.0001), while hyperoncotic HES increased those odds by 92% (OR, 1.92; CI, 1.31-2.81; P = 0.0008). Parallel effects on mortality were observed, with hyperoncotic albumin reducing the odds of death by 48% (OR, 0.52; CI, 0.28-0.95; P = 0.035) and hyperoncotic HES raising those odds by 41% (OR, 1.41; CI, 1.01-1.96; P = 0.043). Conclusions This meta-analysis does not support the hypothesis that hyperoncotic colloid solutions per se injure the kidney. Renal effects appear instead to be colloid-specific, with albumin displaying renoprotection and HES showing nephrotoxicity.
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Affiliation(s)
- Christian J Wiedermann
- Department of Internal Medicine, Central Hospital of Bolzano, Lorenz Böhler Street 5, 39100 Bolzano, Italy.
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Wiedermann CJ, Wiedermann W, Joannidis M. Hypoalbuminemia and acute kidney injury: a meta-analysis of observational clinical studies. Intensive Care Med 2010; 36:1657-1665. [PMID: 20517593 PMCID: PMC7728653 DOI: 10.1007/s00134-010-1928-z] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Accepted: 05/03/2010] [Indexed: 12/20/2022]
Abstract
Purpose To test the hypothesis that hypoalbuminemia is independently associated with increased risk of acute kidney injury (AKI). Methods A meta-analysis was performed of observational clinical studies evaluating the relationship between serum albumin level and the occurrence of AKI by multivariate methods. Additionally, the impact was assessed of lower serum albumin on mortality in patients who developed AKI. Eligible studies were sought by multiple methods, and adjusted odds ratios (OR) were quantitatively combined using a random effects model. Results Seventeen clinical studies with 3,917 total patients were included: 11 studies (6 in surgical or intensive care unit patients and 5 in other hospital settings) evaluating the influence of serum albumin on AKI incidence and 6 studies describing the relationship between serum albumin and mortality among patients who had developed AKI. Lower serum albumin was an independent predictor both of AKI and of death after AKI development. With each 10 g L−1 serum albumin decrement, the odds of AKI increased by 134%. The pooled OR for AKI was 2.34 with a 95% confidence interval (CI) of 1.74–3.14. Among patients who had developed AKI, the odds of death rose 147% (pooled OR 2.47, 95% CI 1.51–4.05) with each 10 g L−1 serum albumin decrement. Conclusions This meta-analysis provides evidence that hypoalbuminemia is a significant independent predictor both of AKI and of death following AKI development. Serum albumin determinations may be of utility in identifying patients at increased risk for AKI or for death after AKI. Controlled studies are warranted to assess interventions aimed at correcting hypoalbuminemia.
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Affiliation(s)
- Christian J Wiedermann
- Division of Internal Medicine, Central Hospital of Bolzano, Lorenz Böhler Street 5, 39100 Bolzano, Italy.
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Ivanov AI, Patel S, Kulchitsky VA, Romanovsky AA. Platelet-activating factor: a previously unrecognized mediator of fever. J Physiol 2003; 553:221-8. [PMID: 14565987 PMCID: PMC2343477 DOI: 10.1113/jphysiol.2003.055616] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Lipopolysaccharide (LPS)-induced systemic inflammation is accompanied by either hypothermia (prevails when the ambient temperature (Ta) is subneutral) or fever (prevails when Ta is neutral or higher). Because platelet-activating factor (PAF) is a proximal mediator of LPS inflammation, it should mediate both thermoregulatory responses to LPS. That PAF possesses hypothermic activity and mediates LPS-induced hypothermia is known. We asked whether PAF possesses pyrogenic activity (Expt 1) and mediates LPS fever (Expt 2). The study was conducted in Long-Evans rats implanted with jugular catheters. A complex with bovine serum albumin (BSA) was infused as a physiologically relevant form of PAF; free (aggregated) PAF was used as a control. In Expt 1, either form of PAF caused hypothermia when infused (83 pmol kg-1 min-1, 60 min, i.v.) at a subneutral Ta of 20 degrees C, but the response to the PAF-BSA complex (-4.5 +/- 0.5 degrees C, nadir) was ~4 times larger than that to free PAF. At a neutral Ta of 30 degrees C, both forms caused fever preceded by tail skin vasoconstriction, but the febrile response to PAF-BSA (1.0 +/- 0.1 degrees C, peak) was > 2 times higher than that to free PAF. Both the hypothermic (at 20 degrees C) and febrile (at 30 degrees C) responses to PAF-BSA started when the total amount of PAF infused was extremely small, < 830 pmol kg-1. In Expt 2 (conducted at 30 degrees C), the PAF receptor antagonist BN 52021 (29 micromol kg-1, i.v.) had no thermal effect of itself. However, it strongly (~2 times) attenuated the febrile response to PAF (5 nmol kg-1, i.v.), implying that this response involves the PAF receptor and is not due to a detergent-like effect of PAF on cell membranes. BN 52021 (but not its vehicle) was similarly effective in attenuating LPS (10 microg kg-1, i.v.) fever. It is concluded that PAF is a highly potent endogenous pyrogenic substance and a mediator of LPS fever.
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Affiliation(s)
- Andrei I Ivanov
- Systemic Inflammation Laboratory, Trauma Research, St Joseph's Hospital and Medical Center, Phoenix, AZ 85013, USA
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Matsuda Y, Shibamoto T, Hayashi T, Saeki Y, Yamaguchi Y, Tanaka S, Koyama S. Renal vascular and sympathetic nerve responses to hypotension induced by platelet-activating factor in anesthetized dogs. Eur J Pharmacol 1993; 250:341-7. [PMID: 8112393 DOI: 10.1016/0014-2999(93)90019-e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
This experiment was designed to determine renal sympathetic and renal vascular responses to platelet-activating factor (PAF)-induced hypotension in anesthetized dogs with and without systemic baroreceptor denervation. The left kidney was perfused at a constant flow, and renal perfusion pressure and efferent left renal sympathetic nerve activity were measured simultaneously. Intrarenal injection of PAF (1.25-5.0 x 10(-2) micrograms/kg, n = 6) produced a dose-dependent increase in renal perfusion pressure without any change in systemic blood pressure. An intravenous injection of PAF (10 micrograms/kg) to intact animals (n = 7) caused an initial increase in renal nerve activity (157 +/- 14%) followed by a gradual reduction below baseline (72 +/- 7%) with concomitant systemic hypotension (from 116 +/- 7 to 46 +/- 6 mmHg). Renal perfusion pressure increased significantly from 84 +/- 2 to 161 +/- 33 mmHg concomitant with an increase in renal nerve activity at 1 min and was maintained at this elevated level throughout the experiment. Similar responses of renal nerve activity and renal perfusion pressure were found in animals with complete systemic baroreceptor denervation (n = 7). These results suggest that renal vascular response during PAF-induced hypotension may presumably be mediated by a direct vasoconstrictor effect of PAF on the renal vasculature and that baroreceptor reflex is not involved in either renal sympathetic or renal vascular changes.
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Affiliation(s)
- Y Matsuda
- Shinshu University School of Medicine, Department of Physiology, Nagano, Japan
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Moritoki H, Hisayama T, Takeuchi S, Miyano H, Kondoh W. Involvement of nitric oxide pathway in the PAF-induced relaxation of rat thoracic aorta. Br J Pharmacol 1992; 107:196-201. [PMID: 1358382 PMCID: PMC1907606 DOI: 10.1111/j.1476-5381.1992.tb14486.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
1. The mechanism of the vasorelaxant effect of platelet activating factor (PAF) on rat thoracic aorta and the effect of aging on the PAF-induced relaxation were investigated. 2. PAF at concentrations causing relaxation induced marked increases in guanosine 3':5'-cyclic monophosphate (cyclic GMP) production, but did not induce an increase in adenosine 3':5'-cyclic monophosphate (cyclic AMP). 3. Removal of the endothelium by mechanical rubbing, and treatment with the PAF antagonists CV-3988, CV-6209 and FR-900452, the nitric oxide biosynthesis inhibitor, NG-nitro L-arginine, the radical scavenger, haemoglobin, and the soluble guanylate cyclase inhibitor, methylene blue, inhibited PAF-induced relaxation and abolished or attenuated PAF-stimulated cyclic GMP production. 4. The relaxation was greatest in arteries from rats aged 4 weeks. With an increase in age, the response of the arteries to PAF was attenuated. 5. Endothelium-dependent cyclic GMP production also decreased with increase in age of the rats. 6. These results suggest that PAF stimulates production of nitric oxide from L-arginine by acting on the PAF receptors in the endothelium, which in turn stimulates soluble guanylate cyclase in the smooth muscle cells, and so increases production of cyclic GMP, thus relaxing the arteries. Age-associated decrease in PAF-induced relaxation may result from a reduction of cyclic GMP formation.
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Affiliation(s)
- H Moritoki
- Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, University of Tokushima, Japan
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Koltai M, Hosford D, Guinot P, Esanu A, Braquet P. PAF. A review of its effects, antagonists and possible future clinical implications (Part II). Drugs 1991; 42:174-204. [PMID: 1717219 DOI: 10.2165/00003495-199142020-00002] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- M Koltai
- Institut Henri Beaufour, Le Plessis Robinson, France
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