Comparative effects of angiotensin II on osmotic water permeability in the toad (Bufo arenarum)

Little is known about the vascular actions of angiotensin II (Ang II) and nitric oxide (NO) in Amphibia. This study investigated (1) Ang II contractility, (2) NO concentrations, and (3) correlations between Ang II contractility, NO concentration and mean arterial pressure (MAP) in isolated Bufo arenarum toad aortic rings. Contractility was measured in isometric conditions, NO concentrations were determined by the Griess reaction, and MAP was determined by a direct method. In isolated toad aortic rings, Ang II produced a contractile response (292.7 +/- 89.2 mg; n = 20). Furthermore, a contractile response to norepinephrine (NE) was also obtained. A significant correlation between both the Ang II and NE contractile responses was found (r = 0.89; n = 11; P < 0.01). Administration of Ang II increased MAP values (Basal 16.8 +/- 1.7; n = 19 vs. Ang II 28.4 +/- 1.8 mmHg; n = 19; P < 0.001), and the increase of MAP by Ang II was positively correlated with the Ang II contractile response (P < 0.01). Administration of L-NAME also increased MAP values, and this effect was higher in those toads that presented a lower pressure response to Ang II (Pearson r = -0.68; P < 0.05). NO was present in all aortic rings, and its concentrations were negatively related to the Ang II contractile response (P < 0.036) and pressure response (Pearson r = -7.08; P < 0.001). These findings suggest that, in the B. arenarum toad, the NO system contra-regulates both the contractile and pressure Ang II responses, although its action could be different in each specimen.

show abstract

Reactivity of isolated toad aortic rings to angiotension II: the role of nitric oxide

Marañón

Turoni

Coviello

et al. 2008

J Comp Physiol B

View full text Add to dashboard Cite

show abstract

Water balance effects of systemic and intracerebroventricular administration of angiotensin II in the toad Bufo arenarum

Reboreda

Segura

1989

Comparative Biochemistry and Physiology Part A: Physiology

View full text Add to dashboard Cite

Effects of angiotensin II and bladder condition on hydration behavior and water uptake in the toad, Bufo woodhousei

Tran

Hoff

Hillyard

1992

Comparative Biochemistry and Physiology Part A: Physiology

View full text Add to dashboard Cite

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Comparative effects of angiotensin II on osmotic water permeability in the toad (Bufo arenarum)

Cited by 11 publications

References 10 publications

Reactivity of isolated toad aortic rings to angiotension II: the role of nitric oxide

Reactivity of isolated toad aortic rings to angiotension II: the role of nitric oxide

Water balance effects of systemic and intracerebroventricular administration of angiotensin II in the toad Bufo arenarum

Effects of angiotensin II and bladder condition on hydration behavior and water uptake in the toad, Bufo woodhousei

Contact Info

Product

Resources

About