Brain Angiotensin and the Female Reproductive Cycle
The existence of the renin-angiotensin system in the brain that synthesizes and regulates angiotensin independently of the blood-borne renin-angiotensin system (RAS) has been shown by a number of experiments, including direct measurements of angiotensin II (Ang II) in blocks of brain and HPLC analysis (1, 2), immunocytochemistry (3), mRNA angiotensinogen (4, 5), ACE mRNA (6) and Ang II release from neurons but not glial cells (7). While a complete understanding of the synthesis of brain angiotensin is still being studied, evidence points to a paracrine process whereby angiotensinogen is expressed in neurons and in glia but the angiotensin I is cleaved to angiotensin II extracellularly by the ectoenzyme angiotensin converting enzyme with Ang II being taken up and stored in neurons and glia (8).
KeywordsLuteinizing Hormone Paraventricular Nucleus Perfusion Fluid Luteinizing Hormone Surge Luteinizing Hormone Peak
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