Angiotensin II (Ang II) has profound effects in the central nervous system (CNS), including promotion of thirst, regulation of vasopressin secretion, and modulation of sympathetic outflow. Despite its importance in cardiovascular and volume homeostasis, angiotensinergic mechanisms are incompletely understood in the CNS. Recently, a novel signaling mechanism for Ang II involving reactive oxygen ...

PURPOSE OF REVIEW Primary hypertension is characterized by Na excess and K deficit in the body, which together are key to its pathogenesis. These derangements work jointly in the brain and the peripheral vascular wall to establish hypertension. In this review, we highlight recent evidence describing the central mechanisms through which Na surfeit and K deficit enhance sympathetic nerve activity...

The existence of a local renin-angiotensin system (RAS) in neurons was first postulated 40 years ago. Further studies indicated intraneuronal generation of ANG II. However, the function and signaling mechanisms of intraneuronal ANG II remained elusive. Since ANG II type 1 receptor (AT1R) is the major type of receptor mediating the effects of ANG II, we used intracellular microinjection and conc...

We have demonstrated that acute third ventricle injections of lead acetate (PbAc) exert a powerful antidipsogenic effect and induce a significant increase in renal sodium excretion. In the present study we confirm the antidipsogenic effect of lead and demonstrate that central administration of this metal, in minute amounts, significantly reduces salt intake both during dehydration and after cen...

Diabetic retinopathy, a common complication of diabetes, develops in 75% of patients with type 1 and 50% of patients with type 2 diabetes, progressing to legal blindness in about 5%. In the recent years, considerable efforts have been put into finding treatments for this condition. It has been discovered that peptidergic mechanisms (neuropeptides and their analogues, activating a diverse array ...

Cerebral catecholamines and angiotensins are both involved in the regulation of cardiovascular function. Recent in vitro studies have suggested that angiotensin II modulates noradrenergic neurotransmission by controlling both the expression and neuritic trafficking of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis. To assess the potential existence of such mec...

In lactating rats, ANG II receptor binding in the arcuate nucleus (ARH) and median eminence is decreased. To further evaluate brain angiotensinergic activity during lactation, we assessed angiotensinogen (AON) mRNA by in situ hybridization in forebrains of day 10 or 11 postpartum lactating and diestrous rats. AON mRNA was abundantly expressed in the ARH, preoptic, suprachiasmatic, supraoptic, p...

Arnold AC, Sakima A, Kasper SO, Vinsant S, Garcia-Espinosa MA, Diz DI. The brain renin-angiotensin system and cardiovascular responses to stress: insights from transgenic rats with low brain angiotensinogen. J Appl Physiol 113: 1929–1936, 2012. First published September 13, 2012; doi:10.1152/japplphysiol.00569.2012.— The renin-angiotensin system (RAS) has been identified as an attractive target...

The effect of central angiotensin AT(1) receptor blockade on thermoregulation and water intake after heat exposure was investigated. Rats were placed in a chamber heated to 39 +/- 1 degrees C for 60 min and then returned to their normal cage (at 22 degrees C), and water intake was measured for 120 min. Artificial cerebrospinal fluid (5 microl) was injected intracerebroventricularly 60 min befor...