The renal and vascular effects of central angiotensin II and atrial natriuretic factor in the anaesthetized rat.

Abstract

SUMMARY1. The interaction between atrial natriuretic factor (ANF) and angiotensin II (Ang II) within the brain to influence renal function and blood pressure was studied in Inactin-anaesthetized male Sprague-Dawley rats.2. Central infusion of ANF produced a diuresis which was associated with a significant decrease in plasma arginine vasopressin (AVP) level. There was no change in sodium excretion rate over the 80 min of intracerebroventricular ANF infusion and ANF produced no detectable change in mean arterial blood pressure.3. Central Ang II administration produced a significant decrease in urine flow, which was associated with elevated plasma AVP, an increase in sodium excretion and a rise in mean arterial blood pressure.4. Combined ANF and Ang II infusion produced an antidiuresis, which was associated with increased plasma AVP concentration. Both the natriuretic and vasopressor actions of central Ang II were abolished when ANF was co-administered.5. It is concluded that ANF and Ang II interact centrally; ANF antagonizes the pressor and natriuretic effects but not the antidiuretic effects of central Ang II. These data suggest the possibility of distinct and separate sites within the brain through which Ang II influences vasopressin release and renal sodium handling and elevates blood pressure.

Natriuretic Hormones in Brain Function

“…In several studies it was postulated that ANP acts in the brain by partially inhibiting the angiotensin II (ANG II) pathway. ANP injection prevented the pressor effect of centrally administered ANG II ( 46 , 51 ). On the behavioral level, centrally administered ANP was shown to inhibit water intake induced by ANG II or dehydration in rats ( 55 ).…”

“…Numerous studies found no change in BP upon central administration of ANP ( 48 – 52 ) or BNP ( 53 ). However, there are reports describing a decrease in vasopressin secretion following central ANP infusion, suggesting that ANP and vasopressin may interact to attenuate the central pressor effects of vasopressin ( 49 , 51 – 54 ). Pretreatment of rats with i.c.v.…”

Interaction between Dopaminergic and Angiotensinergic Systems on Thirst in Adult Male Rats

“…Furthermore, central injection of AT 1 receptor antagonist, Losartan, blocks AT 1 receptors and influences on central angiotensin mechanisms [24,26]. Infusion of Ang II into a lateral cerebral ventricle produce an increase in blood pressure [27,20,28], increase in mean arterial pressure [29,30], decrease in urine flow [27], regulate hydromineral balance [22], induce the pressor response [31], stimulate AVP and OT release [20,28] and elevate RSNA (renal sympathetic nerve activity) [32]. Losartan blocks water intake in intracellular and extracellular dehydrated conditions, inhibits the release of AVP and OT, reduces RSNA response and antidiuretic action [5,32].…”

Epigenetic Programming of Synthesis, Release, and/or Receptor Expression of Common Mediators Participating in the Risk/Resilience for Comorbid Stress-Related Disorders and Coronary Artery Disease

“…Besides the important cardio-renal function of NPs, they also have vasorelaxant effects and they inhibit the renin–angiotensin-aldosterone system (RAAS) and the sympathetic nervous system (SNS) [ 108 , 109 ]. Circulating ANP and vasopressin can interact to attenuate the central pressor effects of vasopressin [ 36 , 110 , 111 , 112 , 113 , 114 ], and brain natriuretic peptide (BNP) suppresses the secretion of vasopressin [ 104 ]. All of these brain regions participate in the regulation of mood and CV responses.…”