Action of Tonin on the Response of Rat on Mesenteric Vessels to Norepinephrine

Kondo, Kazuoki; García, Raúl; Demassieux, S.; Ms, Manku; Df, Horrobin; Boucher, Kenneth M.; Genest, Jacques

doi:10.3181/00379727-155-39746

Cited by 9 publications

(7 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is in agreement with our previous observation in the mesenteric artery preparation- (Kondo et al, 1977) and with the accepted finding that peptide competitive antagonist of angiotensin I1 does not affect the blood pressure in the one-kidney model of hypertension in rats.…”

Section: Discussionsupporting

confidence: 93%

See 1 more Smart Citation

Tonin–Angiotensin II System in Hypertension

et al. 1978

Self Cite

View full text Add to dashboard Cite

1. A single intravenous administration of rabbit tonin antiserum into one-kidney one-clip hypertensive rats restored blood pressure to normal in seven out of ten animals. There was little change in blood pressure in two-kidney one-clip hypertensive, uninephrectomized or sham-operated rats.2. Infusion of tonin in control rats did not modify arterial blood pressure. However, in indomethacin salt-treated rats a marked increase in arterial blood pressure was observed under tonin infusion.3. Plasma tonin activity was significantly increased in human essential and renovascular hypertension.4. These findings strongly suggest that tonin is important in the maintenance of high blood pressure. However, other factors (possibly prostaglandins and sodium) have to be modified in order to activate the tonin-angiotensirt I1 system.

show abstract

Section: Discussionsupporting

confidence: 93%

“…In contrast to angiotensin I and to angiotensin 11, this effect is not blocked by saralasin nor by the converting-enzyme inhibitors (Kondo, Garcia, Demassieux, Manku, Horrobin, Boucher & Genest, 1977). Further, it has been observed that a protein substrate is present in the perfused mesenteric arterial tissue.…”

Section: Introductionmentioning

confidence: 95%

Tonin–Angiotensin II System in Hypertension

et al. 1978

Self Cite

View full text Add to dashboard Cite

show abstract

“…We have previously shown (Kondo et al, 1977) that tonin potentiates the effect of NA on the mesenteric artery of normal rats. In the current study, tonin also potentiated the reactivity of aortic strips to NA.…”

Section: Discussionmentioning

confidence: 98%

Effects of Tonin on Vascular Smooth Muscle of the Hypertensive Rat and Normal Rabbit

et al. 1980

Self Cite

View full text Add to dashboard Cite

1. The response of arterial smooth muscle to noradrenaline was studied in one-clip hypertensive rats with or without the contralateral/kidney and in normotensive rabbits. 2. Strips of aorta from one-kidney, one-clip hypertensive animals were less responsive to noradrenaline than normotensive control rats. The contractile response of strips from two-kidney, one-clip hypertensive animals was not different from the control group. These results suggest that the mechanisms responsible for the lesser reactivity in the one-kidney hypertensive group are not a consequence of elevated blood pressure itself, but may be related to the intrinsic contractility of aortic smooth muscle. 3. Tonin potentiated the contraction induced by noradrenaline in aortic strips from hypertensive and normotensive rats. However, this effect was more important in the one-kidney, one-clip hypertensive animals. In the aortic and mesenteric strips from normal rabbits, tonin produced not only potentiation to noradrenaline but direct contraction. 4. The potentiation to noradrenaline and the direct effect of tonin were not affected by a variety of antagonists but were blocked by a calcium ion antagonist, verapamil, suggesting that tonin may act directly on vascular smooth muscle through mechanisms which might be mediated by calcium ions.

show abstract

“…However, it is interesting to note that tonin did not increase the blood pressure of normotensive rats, 16 an effect also observed in the present study with extracts of rat kidneys. In any case, two observations point to a potential role of tonin in this model of hypertension, namely, the observation that tonin can potentiate the action of norepinephrine and cause direct vasoconstriction in the rat mesenteric preparation by a mechanism that could not be blocked by an angiotensin antagonist, 17 and the recent report that tonin can increase Ca 2+ in the vascular smooth muscle cells of aortic strips from rats with one-kidney, one clip hypertension. 18 Further work is required to establish the relationship, if any, between renopressin and tonin.…”

Section: Discussionmentioning

confidence: 99%

Investigation of the presence of "renopressin" in kidney extracts from rabbits and rats.

Morris¹,

Röper²

1982

Hypertension

View full text Add to dashboard Cite

SUMMARY One-kidney, one clip hypertension may be caused by a renal humoral factor that is not renln. In the search for such a factor, Skeggs and coworkers have provided evidence that certain extracts of rabbit kidneys can increase the blood pressure of other rabbits Indefinitely by a mechanism having a slow onset. In the present experiments an ethanol extract of rabbit kidneys and an acetone extract of a 2.0-4.0 M ammonium sulfate precipitate were injected into rabbits for 10 to 12 days. By Day 3 the Increase in blood pressure (mm Hg) was only 1 ± 3 and 7 ± 2, respectively, but by the end of the injection period, blood pressure had increased by 21 ± 4 (p < 0.025) and 19 ± 4 {p < 0.005). Several weeks later the blood pressure was still significantly elevated above control: 13 ± 2 (p < 0.005) and 15 ± 5 (p < 0.05). A similar pattern of response was seen in unilaterally nephrectomized rabbits. In contrast, injection of an ethanol extract of rat kidneys or a 0.75-2.0 M ammonium sulfate fraction or a 2.0-4.0 M ammonium sulfate fraction or an acetone extract of the latter had no effect on the blood pressure of rats when injected at comparable doses for 13 to 15 days. The ethanol extract of rabbit kidneys caused a mild increase in the blood pressure of rats, but this was not significant. No increase in blood pressure was seen when renal cells from rats with one-kidney, one clip hypertension were Injected lutraperitoneally into normal rats. Therefore, although the present experiments support the existence of renopressin in rabbit kidneys, a similar factor could not be demonstrated in extracts of rat kidneys.

show abstract

Action of Tonin on the Response of Rat on Mesenteric Vessels to Norepinephrine

Cited by 9 publications

References 6 publications

Tonin–Angiotensin II System in Hypertension

Tonin–Angiotensin II System in Hypertension

Effects of Tonin on Vascular Smooth Muscle of the Hypertensive Rat and Normal Rabbit

Investigation of the presence of "renopressin" in kidney extracts from rabbits and rats.

Contact Info

Product

Resources

About