The reactivity to angiotensin of rabbit aorta strips after either alterations of external sodium environment or direct addition of benzydroflumethiazide

Napodano, Rudolph J.; Caliva, Francis S.; Lyons, Chalmers J.; DeSimone, John A.; Lyons, Richard H.

doi:10.1016/0002-8703(62)90035-2

Cited by 10 publications

(5 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is often assumed, generally tacitly, that unresponsiveness to angiotensin with sodium restriction represents a form of angiotensin tachyphylaxis due to the increase in circulating angiotensin levels. However, the two tissues studied, the rabbit leg and aorta, are both resistant to the acute development of angiotensin tachyphylaxis (12,25). It is likely, therefore, either that acute and chronic angiotensin tachyphylaxis are fundamentally different-a concept not easily accounted for at the receptor level-or that a mechanism unrelated to angiotensin tachyphylaxis is involved.…”

Section: Discussionmentioning

confidence: 99%

“…Even for this relatively simple maneuver, a uniform influence on responses to catecholamines of changes in sodium concentration has not been reported. A reduction in sodium concentration results in an increase in tone (7) and potentiation of the responsiveness of the rabbit aortic strip (6); similarly an increase in sodium concentration decreases the responsiveness of this preparation (12). On the other hand, a reduction in sodium concentration reduces the responsiveness of the perfused rat tail (8, 9, 13), rat colon (9), and human and dog limb vascular bed (10, 11).…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Sodium Intake and Vascular Smooth Muscle Responsiveness to Norepinephrine and Angiotensin in the Rabbit

Strewler

Hinrichs

Guiod

et al. 1972

Circulation Research

View full text Add to dashboard Cite

The effect of dietary sodium restriction on the responses to norepinephrine and angiotensin was assessed in two vascular smooth muscle preparations in the rabbit. Sodium restriction reduced the response to angiotensin of both the limb vessels in vivo and the aorta in vitro. The response to norepinephrine was potentiated by sodium restriction in both preparations. The effects on angiotensin responsiveness did not appear to be related to tachyphylaxis, changes in extracellular electrolyte composition, or nonspecific depression of smooth muscle function. Probably, the change in sodium intake induced a change in the smooth muscle cell membranes which modified the affinity of their receptors for angiotensin and norepinephrine.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Sodium Intake and Vascular Smooth Muscle Responsiveness to Norepinephrine and Angiotensin in the Rabbit

Strewler

Hinrichs

Guiod

et al. 1972

Circulation Research

View full text Add to dashboard Cite

show abstract

“…The vasoconstrictive response of isolated vascular smooth muscle to intraluminal flow was diminished by 20% when the [Na + ] e was reduced by 10 mM [8]. However, several investigators have reported that reduction of [Na + ] e did not alter contractile responses of resistance vessels to norepinephrine, nor their relaxation to acetylcholine and papaverine [7,18], while others [19,20] reported that such responses were enhanced and some reported that vascular reactivity was reduced when [Na + ] e was reduced [6,21]. Hyperosmolarity has been reported both to cause vasoconstriction and enhance responses of isolated vascular smooth muscles to agonists [9,10,11].…”

Section: Discussionmentioning

confidence: 99%

The effect of sodium based hypo-osmolality on arterial smooth muscle reactivity in vitro

Ezimokhai

Osman

1997

Res. Exp. Med.

View full text Add to dashboard Cite

The study tested the hypothesis that the reduced [Na+]e and hypo-osmolality of normal pregnancy are causally linked to the attenuation of vascular smooth muscle reactivity in vitro. Aortic rings from nonpregnant female rats were incubated in physiological medium containing 114 mM NaCl/l and the contractile responses to phenylephrine, KCl and CaCl2 as well as the relaxations to acetylcholine and KCl were compared with those of rings incubated in normal medium containing 119 mM NaCl/l. There was no solute substituted for the lowered [Na+]. Experiments with phenylephrine were repeated using de-endothelialized rings and intact rings pretreated with indomethacin. Contractile responses of intact rings (n = 11) in hypo-osmolar solution to phenylephrine were significantly (P < 0.001) lower than of those in normal medium (n = 11). Responses were partially restored by endothelial denudation but not in the presence of indomethacin. Relaxations to acetylcholine (n = 7 for hypo-osmolar; n = 6 for normal solution) and KCl (n = 7 for each of hypo- and normal osmolar) were significantly enhanced (P < 0.05) in rings incubated in hypo-osmolar solution. There was no significant difference between the responses of the rings to KCl, and CaCl2 in either solution. These effects are similar to some of those previously described for vascular smooth muscle in normal pregnancy suggesting that the reduced [Na+]e and hypo-osmolarity of normal pregnancy may be contributing to the diminished vascular reactivity.

show abstract

“…Dodd and Daniel (1960) reported a progres sive decrease in responsiveness o f the rabbit aorta during incubation in sodium-free medium. Napodano et al (1962) observed an increased response of rabbit aortic strips to angiotensin 11 when the external sodium was reduced by 25% during contact of the agonist with the tissue; conversely, when the external sodium was in creased during contact o f angiotensin II with the tissue, the size of the response was reduced. Bohr et al (1969) observed a potentiation of the response to NE when isolated rabbit aortae were exposed to sodium-free medium, but they allowed only a 30-sec equilibration period in this new bathing medium before addition of agonist.…”

Section: Effect O F K*-free Krebsmentioning

confidence: 94%

The Role of Sodium and Potassium Ions in the Contractile Response and Development of Tachyphylaxis to Angiotensin II on Vascular Smooth Muscle

Moore¹,

Khairallah²

1979

J Vasc Res

View full text Add to dashboard Cite

The role of sodium and potassium ions, and the possible involvement of the membrane sodium pump has been studied in the development of a contractile response to, and the development of tachyphylaxis to, angiotensin II. It is suggested that a membrane depolarization may have a role in the mechanism of the contractile response to angiotensin II, as responses of the rabbit aorta to angiotensin II were selectively inhibited in K-free medium. Acute or chronic increases in medium sodium, however, did not influence the response of the rabbit aorta to angiotensin II. On the rat aorta increased medium sodium concentrations potentiated the response to angiotensin II and inhibited the development of tachyphylaxis. Membrane depolarization or hyperpolarization does not appear to be part of the mechanism of development of tachyphylaxis to angiotensin II on the rat aorta, as response to both NE and angiotensin II were inhibited equally by exposure of the rat aorta to K-free medium, i.e., nonspecific desensitization occurred, as opposed to the specific desensitization which defines tachyphylaxis.

show abstract

The reactivity to angiotensin of rabbit aorta strips after either alterations of external sodium environment or direct addition of benzydroflumethiazide

Cited by 10 publications

References 9 publications

Sodium Intake and Vascular Smooth Muscle Responsiveness to Norepinephrine and Angiotensin in the Rabbit

Sodium Intake and Vascular Smooth Muscle Responsiveness to Norepinephrine and Angiotensin in the Rabbit

The effect of sodium based hypo-osmolality on arterial smooth muscle reactivity in vitro

The Role of Sodium and Potassium Ions in the Contractile Response and Development of Tachyphylaxis to Angiotensin II on Vascular Smooth Muscle

Contact Info

Product

Resources

About