Biological activities of angiotensin II-(1–6)-hexapeptide and angiotensin II-(1–7)-heptapeptide in man

Effects of angiotensin II and angiotensin-(1-7) on the release of [3H]norepinephrine from rat atria.

“…5 ' 6 Although some of the responses elicited by Ang-(l-7) were similar to those of Ang II, 5 -8 different actions for both peptides were also reported; ie, the heptapeptide is not a dipsogen, 9 a constrictor agent of blood vessels, 10 or an aldosterone secretagogue. 10 Moreover, different actions of both peptides in the regulation of cell function were found in isolated rabbit vasa deferentia, where Ang-(1-7) was as potent as Ang II in increasing prostaglandin synthesis but was devoid of the neuromodulatory activity found for Ang II. 11 The aim of the present work was to compare the effects of the heptapeptide and of Ang II in the release of [ 3 H]norepinephrine ([ 3 H]NE) in rat atria isolated with their cardioaccelerans nerves.…”

Angiotensin-(1-7) Reduces Norepinephrine Release Through a Nitric Oxide Mechanism in Rat Hypothalamus

“…In addition, type 1 (AT 1 ) and type 2 (AT 2 ) Ang receptors were described in several regions and nucleus of the central nervous system, including the hypothalamus. 3,4 Although Ang-(1-7) is not an agonist in terms of activating vasoconstriction, 5 stimulating thirst, 6 or promoting aldosterone secretion, 5 the heptapeptide causes neuronal excitation in the paraventricular nucleus of hypothalamus and dorsal vagal complex of the medulla oblongata, 7 facilitates the noradrenergic neurotransmission, 8 and stimulates prostaglandin 9 -11 and vasopressin release 12 with potency comparable to that of Ang II. Conversely, some of the effects of Ang-(1-7) are opposite to those elicited by Ang II, that is, it displays an antiproliferative action on vascular smooth muscle cells, 13 produces natriuresis 14 and diuresis 15 as well as vasodilation, 16,17 and facilitates the baroreflex activity.…”

Agonistic activities of isoleucine8-angiotensin II in man.

“…In addition, it was demonstrated recently that ANG-(1-7) had minimal pressor and renin-suppressing actions but no steroidogenic action in man and that the binding portion in ANG II molecule for human arteriolar ANG II receptor was not Cterminal phenylalanine (Kono et al, 1986). Therefore, although phenylalanine in position 8 is very important in maintaining physiologically sufficient actions of ANG II, an amino acid in position 8 should not necessarily be phenylalanine in order to more or less main- tain pressor, renin-suppressing and steroidogenic activities in man.…”

“…In sheep no aldosterone-stimulating activity was observed with Va15-ANG-(1-7) (Blair-West et al, 1971). Very recently isoleucine5-angiotensin II-(1-7)-heptapeptide [ANG-(1-7)] was reported to have a minimal pressor [less than 0.028% of isoleucine5-angiotensin II (Ile5-ANG II)] and very slight renin-suppressing but no steroidogenic activities in man (Kono et al, 1986). However, there has been no report on the agonistic activities of isoleucine8-angiotensin II (Ile8-ANG II), a C-terminal substituted ANG II, in animals or man.…”