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Full-Text Articles in Medicine and Health Sciences
At₁ Angiotensin Ii Receptor And Novel Non-At₁, Non-At₂ Angiotensin Ii/Iii Binding Site In Brainstem Cardiovascular Regulatory Centers Of The Spontaneously Hypertensive Rat, Erick A. Bourassa, Xiefan Fang, Xia Li, Alan F. Sved, Robert C. Speth
At₁ Angiotensin Ii Receptor And Novel Non-At₁, Non-At₂ Angiotensin Ii/Iii Binding Site In Brainstem Cardiovascular Regulatory Centers Of The Spontaneously Hypertensive Rat, Erick A. Bourassa, Xiefan Fang, Xia Li, Alan F. Sved, Robert C. Speth
HPD Articles
Spontaneously hypertensive rats (SHR) have an activated brain angiotensin system that contributes to the elevation of blood pressure in this animal model. Physiological and pharmacological studies suggest that hyperactivation of brain AT₁ angiotensin receptors is a major pathophysiological factor. Consistent with these observations, radioligand binding studies indicate widespread up-regulation of brain angiotensin receptors in SHR. One key brainstem site in which AT₁ receptor stimulation appears to contribute to the elevated blood pressure in SHR is the rostral ventrolateral medulla (RVLM). However, no quantitative comparison of AT₁ receptor binding in the RVLM has been made in SHR versus normotensive rats. A …
Distribution Of A Novel Binding Site For Angiotensins Ii And Iii In Mouse Tissues, Felicia M. Rabey, Vardan T. Karamyan, Robert C. Speth
Distribution Of A Novel Binding Site For Angiotensins Ii And Iii In Mouse Tissues, Felicia M. Rabey, Vardan T. Karamyan, Robert C. Speth
HPD Articles
A novel binding site for angiotensins II and III that is unmasked by parachloromercuribenzoate has been reported in rat, mouse and human brains. Initial studies of this binding site indicate that it is not expressed in the adrenal, liver or kidney of the rat and mouse. To determine if this binding site occurs in other mouse tissues, 8 tissues were assayed for expression of this binding site by radioligand binding assay and compared with the expression of this binding site in the forebrain. Particulate fractions of homogenates of testis, epididymis, seminal vesicles, heart, spleen, pancreas, lung, skeletal muscle, and forebrain …
Preliminary Biochemical Characterization Of The Novel, Non-At1, Non-At2 Angiotensin Binding Site From The Rat Brain, Vardan T. Karamyan, Jason Arsenault, Emanuel Escher, Robert C. Speth
Preliminary Biochemical Characterization Of The Novel, Non-At1, Non-At2 Angiotensin Binding Site From The Rat Brain, Vardan T. Karamyan, Jason Arsenault, Emanuel Escher, Robert C. Speth
HPD Articles
A novel binding site for angiotensins II and III was recently discovered in brain membranes in the presence of the sulfhydryl reactive angiotensinase inhibitor parachloromercuribenzoate. This binding site is distinctly different from the other known receptors for angiotensins: AT₁, AT₂, AT₄, and mas oncogene protein (Ang 1-7 receptor). Preliminary biochemical characterization studies have been done on this protein by crosslinking it with (125)I-labeled photoaffinity probes and solubilizing the radiolabeled binding site. Polyacrylamide gel electrophoresis studies and isoelectric focusing indicate that this membrane bound binding site is a protein with a molecular weight of 70-85 kDa and an isoelectric point of …
Angiotensin-Converting Enzyme 2: A New Target For Neurogenic Hypertension, Yumei Feng, Huijing Xia, Robson A. Santos, Robert Speth, Eric Lazartigues
Angiotensin-Converting Enzyme 2: A New Target For Neurogenic Hypertension, Yumei Feng, Huijing Xia, Robson A. Santos, Robert Speth, Eric Lazartigues
HPD Articles
Overactivity of the renin-angiotensin system (RAS) is involved in the pathogenesis of hypertension, and an overactive brain RAS has been highlighted in several genetic and experimental models. Until now, angiotensin II (Ang II) was thought to be the main effector of this system, and the angiotensin-converting enzyme (ACE)-Ang II-Ang II type 1 receptor axis was the main target for antihypertensive therapies. A new member of the RAS, ACE2 (angiotensin-converting enzyme type 2), has been identified in organs and tissues related to cardiovascular function (e.g. heart, kidney and blood vessels) and appears to be part of a counter-regulatory pathway to buffer …
Brain-Selective Overexpression Of Human Angiotensin-Converting Enzyme Type 2 Attenuates Neurogenic Hypertension, Yumei Feng, Huijing Xia, Yanhui Cai, Carmen M. Halabi, Lenice K. Becker, Robson A. Santos, Robert C. Speth, Curt D. Sigmund, Eric Lazartigues
Brain-Selective Overexpression Of Human Angiotensin-Converting Enzyme Type 2 Attenuates Neurogenic Hypertension, Yumei Feng, Huijing Xia, Yanhui Cai, Carmen M. Halabi, Lenice K. Becker, Robson A. Santos, Robert C. Speth, Curt D. Sigmund, Eric Lazartigues
HPD Articles
RATIONALE: Angiotensin converting enzyme type 2 (ACE2) is a new member of the brain renin-angiotensin system, that might be activated by an overactive renin-angiotensin system. OBJECTIVE: To clarify the role of central ACE2 using a new transgenic mouse model with human (h)ACE2 under the control of a synapsin promoter, allowing neuron-targeted expression in the central nervous system. METHODS AND RESULTS: Syn-hACE2 (SA) transgenic mice exhibit high hACE2 protein expression and activity throughout the brain. Baseline hemodynamic parameters (telemetry), autonomic function, and spontaneous baroreflex sensitivity (SBRS) were not significantly different between SA mice and nontransgenic littermates. Brain-targeted ACE2 overexpression attenuated the …