Angiotensin‐converting enzyme inhibitors and the role of nitric oxide and excitatory amino acids in improvement of cognition and memory

Marı́n, Jesús; Govantes, Carlos

doi:10.1111/j.1474-8673.1995.tb00298.x

Cited by 13 publications

(2 citation statements)

References 124 publications

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“…Moreover, Ang IV could be produced directly from Ang I by the action of the neuronal endopeptidase 24.11 cleaving the Arg 2 -Val 3 bond of Ang I followed by the sequential carboxypeptidase action removing Leu 10 and His 9 from the resulting Ang I (3-10) octapeptide. 33,52 Such an alternative pathway of Ang IV formation omitting the Ang II step offers an attractive explanation of the cognition-enhancing properties of angiotensinconverting enzyme inhibitors (ACE-Is), observed in humans 53,54 and in animals 55,56 by the possible facilitation of Ang IV and Ang II (3-7) production by the alternative pathways. 33 59 or the hippocampus.…”

Section: Discussionmentioning

confidence: 99%

Cognitive Effects Attributed to Angiotensin II may Result from its Conversion to Angiotensin IV

Braszko

Walesiuk

Wielgat

2006

J Renin Angiotensin Aldosterone Syst

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This study tests the hypothesis that the facilitation of learning and improvement of memory observed after an intracerebroventricular (i.c.v.) injection of angiotensin II (Ang II) is, in fact, caused by its derivative angiotensin IV (Ang IV). We ran two memory tests as well as an auxiliary test assessing motor performance in rats injected (i.c.v., 1 nmol in 2 microl saline) with Ang II or Ang IV. There were separate groups receiving peptide or saline five, 10 and 15 minutes before testing. Ang IV significantly increased step-through latencies in a passive avoidance paradigm as well as improved discrimination between familiar and unfamiliar objects in an object recognition test in all groups showing better retrieval of memory of aversive as well as appetitive stimuli in the peptide-treated groups regardless of the time of its injection. In contrast, rats treated with Ang II demonstrated significant improvement of memory of aversive and appetitive stimuli in the same tests only 15 minutes after its i.c.v. injection, with no effect in the groups injected five minutes before testing and slight efficacy in those injected 10 minutes before the test. Numbers of crossings, rearings and bar approaches in an open field were similar both in the peptide-treated and control groups making it unlikely that changes in motor performance affected the memory tests. In line with the present views on the intracellular metabolism of Ang II, these results suggest degradation to Ang IV by aminopeptidases A and N is necessary before the cognitive effects can occur.

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Section: Discussionmentioning

confidence: 99%

Cognitive Effects Attributed to Angiotensin II may Result from its Conversion to Angiotensin IV

Braszko

Walesiuk

Wielgat

2006

J Renin Angiotensin Aldosterone Syst

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show abstract

“…Tissue ACE is also important in the modulation of a number of neurotransmitters including encephalins, endorphins, neurotensin, substance P and kinins. It may be that changes in the levels of these substances may influence cognition [18]. This also provides a potential target for therapy: ACE inhibitors increase the levels of the above neurotransmitters and through their effect on kinins raise concentrations of excitatory aminoacids, nitric oxide, prostaglandins, noradrenaline, and acetylcholine.…”

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confidence: 99%