The Experts below are selected from a list of 135 Experts worldwide ranked by ideXlab platform
S M Cobbe - One of the best experts on this subject based on the ideXlab platform.
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increase in plasma beta Endorphins precedes vasodepressor syncope
Heart, 1994Co-Authors: D R Wallbridge, H E Macintyre, C E Gray, M Denvir, Keith G Oldroyd, Alan P Rae, S M CobbeAbstract:BACKGROUND--Endogenous opioids have a tonic inhibitory effect on sympathetic tone and have been implicated in the pathophysiology of vasodepressor syncope. Plasma beta Endorphin concentrations increase after vasodepressor syncope induced by exercise or by fasting. AIMS--To take frequent samples for plasma beta Endorphin estimation during tilt testing, and to determine whether plasma beta Endorphin increased before the start of syncope. PATIENTS--24 patients undergoing tilt testing for investigation of unexplained syncope. SETTING--Tertiary referral centre. METHODS--Blood samples were obtained during 70 degrees head up tilt testing. Plasma beta Endorphin concentrations were estimated by radioimmunoassay (mean(SD) pmol/l). RESULTS--Patients with a positive test showed a rise in beta Endorphin concentrations before syncope baseline 4.4(1.5) v start of syncope 8.5(3.1), p < 0.002). In contrast, patients with a negative test showed no change in beta Endorphin concentrations (baseline 3.4(1.0) v end of test 4.5(2.3), NS). After syncope all patients showed a large secondary increase in beta Endorphins (32.3(18.6)). CONCLUSION--An increase in plasma beta Endorphins precedes vasodepressor syncope. This finding supports a pathophysiological role for endogenous opioids.
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Increase in plasma beta Endorphins precedes vasodepressor syncope.
British heart journal, 1994Co-Authors: D R Wallbridge, H E Macintyre, C E Gray, M Denvir, Keith G Oldroyd, Alan P Rae, S M CobbeAbstract:Endogenous opioids have a tonic inhibitory effect on sympathetic tone and have been implicated in the pathophysiology of vasodepressor syncope. Plasma beta Endorphin concentrations increase after vasodepressor syncope induced by exercise or by fasting. To take frequent samples for plasma beta Endorphin estimation during tilt testing, and to determine whether plasma beta Endorphin increased before the start of syncope. 24 patients undergoing tilt testing for investigation of unexplained syncope. Tertiary referral centre. Blood samples were obtained during 70 degrees head up tilt testing. Plasma beta Endorphin concentrations were estimated by radioimmunoassay (mean(SD) pmol/l). Patients with a positive test showed a rise in beta Endorphin concentrations before syncope baseline 4.4(1.5) v start of syncope 8.5(3.1), p < 0.002). In contrast, patients with a negative test showed no change in beta Endorphin concentrations (baseline 3.4(1.0) v end of test 4.5(2.3), NS). After syncope all patients showed a large secondary increase in beta Endorphins (32.3(18.6)). An increase in plasma beta Endorphins precedes vasodepressor syncope. This finding supports a pathophysiological role for endogenous opioids.
D R Wallbridge - One of the best experts on this subject based on the ideXlab platform.
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increase in plasma beta Endorphins precedes vasodepressor syncope
Heart, 1994Co-Authors: D R Wallbridge, H E Macintyre, C E Gray, M Denvir, Keith G Oldroyd, Alan P Rae, S M CobbeAbstract:BACKGROUND--Endogenous opioids have a tonic inhibitory effect on sympathetic tone and have been implicated in the pathophysiology of vasodepressor syncope. Plasma beta Endorphin concentrations increase after vasodepressor syncope induced by exercise or by fasting. AIMS--To take frequent samples for plasma beta Endorphin estimation during tilt testing, and to determine whether plasma beta Endorphin increased before the start of syncope. PATIENTS--24 patients undergoing tilt testing for investigation of unexplained syncope. SETTING--Tertiary referral centre. METHODS--Blood samples were obtained during 70 degrees head up tilt testing. Plasma beta Endorphin concentrations were estimated by radioimmunoassay (mean(SD) pmol/l). RESULTS--Patients with a positive test showed a rise in beta Endorphin concentrations before syncope baseline 4.4(1.5) v start of syncope 8.5(3.1), p < 0.002). In contrast, patients with a negative test showed no change in beta Endorphin concentrations (baseline 3.4(1.0) v end of test 4.5(2.3), NS). After syncope all patients showed a large secondary increase in beta Endorphins (32.3(18.6)). CONCLUSION--An increase in plasma beta Endorphins precedes vasodepressor syncope. This finding supports a pathophysiological role for endogenous opioids.
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Increase in plasma beta Endorphins precedes vasodepressor syncope.
British heart journal, 1994Co-Authors: D R Wallbridge, H E Macintyre, C E Gray, M Denvir, Keith G Oldroyd, Alan P Rae, S M CobbeAbstract:Endogenous opioids have a tonic inhibitory effect on sympathetic tone and have been implicated in the pathophysiology of vasodepressor syncope. Plasma beta Endorphin concentrations increase after vasodepressor syncope induced by exercise or by fasting. To take frequent samples for plasma beta Endorphin estimation during tilt testing, and to determine whether plasma beta Endorphin increased before the start of syncope. 24 patients undergoing tilt testing for investigation of unexplained syncope. Tertiary referral centre. Blood samples were obtained during 70 degrees head up tilt testing. Plasma beta Endorphin concentrations were estimated by radioimmunoassay (mean(SD) pmol/l). Patients with a positive test showed a rise in beta Endorphin concentrations before syncope baseline 4.4(1.5) v start of syncope 8.5(3.1), p < 0.002). In contrast, patients with a negative test showed no change in beta Endorphin concentrations (baseline 3.4(1.0) v end of test 4.5(2.3), NS). After syncope all patients showed a large secondary increase in beta Endorphins (32.3(18.6)). An increase in plasma beta Endorphins precedes vasodepressor syncope. This finding supports a pathophysiological role for endogenous opioids.
Chhabil Dass - One of the best experts on this subject based on the ideXlab platform.
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quantification of endogenous α and γ Endorphins in rat brain by liquid chromatography tandem mass spectrometry
Analytical Biochemistry, 2009Co-Authors: Hari Kosanam, Suma Ramagiri, Chhabil DassAbstract:Abstract Quantification of α- and γ-Endorphins in rat brain using liquid chromatography–electrospray ionization–tandem mass spectrometry is described. [D-Ala2]-γ-Endorphin is used as an internal standard. The precursor-to-product ion MRM transitions for α-Endorphin, γ-Endorphin, and [D-Ala2]-γ-Endorphin were m/z 873.6 → 429.6; 929.6 → 542.3; 936.6 → 542.3, respectively. The method was validated in terms of linearity, specificity, sensitivity, recovery, precision, and accuracy. The assay was linear over a concentration range of 0.1–200 ng/mL with the limit-of-detection of 0.03 ng/mL and limit-of-quantification of 0.1 ng/mL. The endogenous concentrations of α- and γ-Endorphins in rat brains were 13.8 ± 0.57 (mean ± SD; n = 5) and 2.5 ± 0.43 ng/g of wet tissue weight, respectively.
H E Macintyre - One of the best experts on this subject based on the ideXlab platform.
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increase in plasma beta Endorphins precedes vasodepressor syncope
Heart, 1994Co-Authors: D R Wallbridge, H E Macintyre, C E Gray, M Denvir, Keith G Oldroyd, Alan P Rae, S M CobbeAbstract:BACKGROUND--Endogenous opioids have a tonic inhibitory effect on sympathetic tone and have been implicated in the pathophysiology of vasodepressor syncope. Plasma beta Endorphin concentrations increase after vasodepressor syncope induced by exercise or by fasting. AIMS--To take frequent samples for plasma beta Endorphin estimation during tilt testing, and to determine whether plasma beta Endorphin increased before the start of syncope. PATIENTS--24 patients undergoing tilt testing for investigation of unexplained syncope. SETTING--Tertiary referral centre. METHODS--Blood samples were obtained during 70 degrees head up tilt testing. Plasma beta Endorphin concentrations were estimated by radioimmunoassay (mean(SD) pmol/l). RESULTS--Patients with a positive test showed a rise in beta Endorphin concentrations before syncope baseline 4.4(1.5) v start of syncope 8.5(3.1), p < 0.002). In contrast, patients with a negative test showed no change in beta Endorphin concentrations (baseline 3.4(1.0) v end of test 4.5(2.3), NS). After syncope all patients showed a large secondary increase in beta Endorphins (32.3(18.6)). CONCLUSION--An increase in plasma beta Endorphins precedes vasodepressor syncope. This finding supports a pathophysiological role for endogenous opioids.
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Increase in plasma beta Endorphins precedes vasodepressor syncope.
British heart journal, 1994Co-Authors: D R Wallbridge, H E Macintyre, C E Gray, M Denvir, Keith G Oldroyd, Alan P Rae, S M CobbeAbstract:Endogenous opioids have a tonic inhibitory effect on sympathetic tone and have been implicated in the pathophysiology of vasodepressor syncope. Plasma beta Endorphin concentrations increase after vasodepressor syncope induced by exercise or by fasting. To take frequent samples for plasma beta Endorphin estimation during tilt testing, and to determine whether plasma beta Endorphin increased before the start of syncope. 24 patients undergoing tilt testing for investigation of unexplained syncope. Tertiary referral centre. Blood samples were obtained during 70 degrees head up tilt testing. Plasma beta Endorphin concentrations were estimated by radioimmunoassay (mean(SD) pmol/l). Patients with a positive test showed a rise in beta Endorphin concentrations before syncope baseline 4.4(1.5) v start of syncope 8.5(3.1), p < 0.002). In contrast, patients with a negative test showed no change in beta Endorphin concentrations (baseline 3.4(1.0) v end of test 4.5(2.3), NS). After syncope all patients showed a large secondary increase in beta Endorphins (32.3(18.6)). An increase in plasma beta Endorphins precedes vasodepressor syncope. This finding supports a pathophysiological role for endogenous opioids.
C E Gray - One of the best experts on this subject based on the ideXlab platform.
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increase in plasma beta Endorphins precedes vasodepressor syncope
Heart, 1994Co-Authors: D R Wallbridge, H E Macintyre, C E Gray, M Denvir, Keith G Oldroyd, Alan P Rae, S M CobbeAbstract:BACKGROUND--Endogenous opioids have a tonic inhibitory effect on sympathetic tone and have been implicated in the pathophysiology of vasodepressor syncope. Plasma beta Endorphin concentrations increase after vasodepressor syncope induced by exercise or by fasting. AIMS--To take frequent samples for plasma beta Endorphin estimation during tilt testing, and to determine whether plasma beta Endorphin increased before the start of syncope. PATIENTS--24 patients undergoing tilt testing for investigation of unexplained syncope. SETTING--Tertiary referral centre. METHODS--Blood samples were obtained during 70 degrees head up tilt testing. Plasma beta Endorphin concentrations were estimated by radioimmunoassay (mean(SD) pmol/l). RESULTS--Patients with a positive test showed a rise in beta Endorphin concentrations before syncope baseline 4.4(1.5) v start of syncope 8.5(3.1), p < 0.002). In contrast, patients with a negative test showed no change in beta Endorphin concentrations (baseline 3.4(1.0) v end of test 4.5(2.3), NS). After syncope all patients showed a large secondary increase in beta Endorphins (32.3(18.6)). CONCLUSION--An increase in plasma beta Endorphins precedes vasodepressor syncope. This finding supports a pathophysiological role for endogenous opioids.
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Increase in plasma beta Endorphins precedes vasodepressor syncope.
British heart journal, 1994Co-Authors: D R Wallbridge, H E Macintyre, C E Gray, M Denvir, Keith G Oldroyd, Alan P Rae, S M CobbeAbstract:Endogenous opioids have a tonic inhibitory effect on sympathetic tone and have been implicated in the pathophysiology of vasodepressor syncope. Plasma beta Endorphin concentrations increase after vasodepressor syncope induced by exercise or by fasting. To take frequent samples for plasma beta Endorphin estimation during tilt testing, and to determine whether plasma beta Endorphin increased before the start of syncope. 24 patients undergoing tilt testing for investigation of unexplained syncope. Tertiary referral centre. Blood samples were obtained during 70 degrees head up tilt testing. Plasma beta Endorphin concentrations were estimated by radioimmunoassay (mean(SD) pmol/l). Patients with a positive test showed a rise in beta Endorphin concentrations before syncope baseline 4.4(1.5) v start of syncope 8.5(3.1), p < 0.002). In contrast, patients with a negative test showed no change in beta Endorphin concentrations (baseline 3.4(1.0) v end of test 4.5(2.3), NS). After syncope all patients showed a large secondary increase in beta Endorphins (32.3(18.6)). An increase in plasma beta Endorphins precedes vasodepressor syncope. This finding supports a pathophysiological role for endogenous opioids.
