Chapter iii Localization of angiotensin receptors in the nervous system

Review: AT1-receptors in the central nervous system

“…Thus AT 1 -receptors occur in the brainstem nuclei involved in the regulation of heart rate and sympathetic vasomotor activity, and thus BP. 31 Overall, we can say that the distribution of the AT 1 -receptor is highly conserved across all species studied and is associated with regions of the brain known to be involved in fluid and electrolyte balance, control of neuroendocrine function and central regulation of autonomic activity. 31 In contrast, AT 2 -receptor distribution is very variable between species and the only constant site of expression in the adult brain is in the molecular layer of the cerebellar cortex.…”

“…31 Overall, we can say that the distribution of the AT 1 -receptor is highly conserved across all species studied and is associated with regions of the brain known to be involved in fluid and electrolyte balance, control of neuroendocrine function and central regulation of autonomic activity. 31 In contrast, AT 2 -receptor distribution is very variable between species and the only constant site of expression in the adult brain is in the molecular layer of the cerebellar cortex. 32 Whilst having a wide distribution in the rat, 23,26 the AT 2 -receptor only occurs in a very limited number of sites in the adult brain in other species.…”

“…[28][29][30] Detailed maps of the distributions of these receptors are included in several recent comprehensive reviews. 9,31,32 Most circumventricular organs, including the subfornical organ, vascular organ of the lamina terminalis (OVLT), median eminence, anterior pituitary and the area postrema of the hindbrain, contain high densities of AT 1 -receptors. 9,23 These regions are exposed to blood-borne Ang II and are the sites where systemic Ang II may act to alter drinking and salt appetite, blood pressure (BP), and pituitary hormone release.…”

Training-Induced Pressure Fall in Spontaneously Hypertensive Rats Is Associated With Reduced Angiotensinogen mRNA Expression Within the Nucleus Tractus Solitarii

“…2,4 -6 All of the components of the RAS (precursor, enzymes, peptides, and receptors) are present in brain areas involved in cardiovascular control as the hypothalamic paraventricular nucleus and dorsal brain stem areas including the nucleus tractus solitarii (NTS), the dorsal motor nucleus of the vagus nerve, and the area postrema. 4,[7][8][9][10][11] It is important to notice that angiotensinogen (Aogen), angiotensin II (Ang II), and Ang II type 1 (AT 1A ) receptors are densely expressed within the NTS, indicating the importance of local RAS on cardiovascular control. 4,8,10 -14 In previous studies we showed both the close relationship between increased Aogen and Ang II AT 1A receptor mRNA expression in brain stem areas and elevated blood pressure 14 and the permissive role of Ang II to orchestrate, via AT 1 receptors, the detrimental cardiovascular responses during development of hypertension.…”

Estudo das vias intracelulares de sinalização da insulina e da angiotensina-II no hipotálamo de ratas grávidas e lactantes.

“…A Ang-II cerebral pode ainda ser clivada pela aminopeptidase A, uma zinco metalopeptidase, que retira o N-terminal do resíduo aspartil da Ang-II formando o heptapeptídeo angiotensina III (Ang-III), o qual pode ainda ser degradado ao hexapeptídeo angiotensina IV (Ang-IV) pela aminopeptidase N (REUX et al, 1999b). Os receptores da Ang-II, também podem ser encontrados em diversas áreas cerebrais e da medula espinhal (ALLEN et al, 2000;LENKEI et al, 1997). O receptor AT1 está fortemente presente nos neurônios do ARC, onde estimula a liberação de dopamina em resposta a Ang-II, o que leva à redução da liberação de prolactina (PRL) (JOHREN et al, 1997).…”