What is the clinical evidence from this study?

Study design: Other. Intervention: Mg2+ withdrawal and Na+ reduction vs. Female rats / normal media. Primary outcome: Tension development in isolated aortae.

What question did this study set out to answer?

To determine whether sex-dependent differences exist in vascular smooth muscle tone during extracellular magnesium and sodium withdrawal and to clarify the roles of the endothelium and estrogen.

February 1, 1992British Journal of PharmacologyOpen Access

Endothelial‐dependent sexual dimorphism in vascular smooth muscle: role of Mg2+ and Na+

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Key result

Mg2+ withdrawal and Na+ reduction induced significant increases in basal tone in intact aortae of male rats but not female rats, suggesting female sex hormones modify endothelial functions.

Population

Isolated aortae from male and female rats

Comparison

Exposure to Mg2+-free and low-Na+ media vs Normal media, or comparison between sexes and…

Design

Preclinical

Authors

BABella T. AlturaState University of New York

Discussion

Member takes

Implication

These animal findings should not change practice; hypothesis-generating for oestradiol-mediated endothelial protection against human ischaemic disease.

Key Points

To determine whether sex-dependent differences exist in vascular smooth muscle tone during extracellular magnesium and sodium withdrawal and to clarify the roles of the endothelium and estrogen.
Measured isometric tension development in isolated aortic rings with and without intact endothelium from adult male, adult female, sexually immature, and estradiol-treated castrated male rats.
Exposed tissues to magnesium-free, low-sodium (84 mM) solutions under calcium-free conditions, magnesium re-addition, and pharmacological inhibition of endothelial-derived relaxing factor and nitric oxide.
Withdrawal of magnesium combined with reduced sodium significantly increased basal tone in intact male aortae, whereas intact female aortae developed no tension.
Removal of the endothelium restored marked tension development in female aortae, while estradiol treatment in castrated males completely prevented tension development.
Tension responses were abolished in calcium-free media, reversed by restoring 1.2 mM magnesium, and triggered in intact female aortae by endothelial-derived relaxing factor inhibitors methylene blue and hemoglobin.

Structured PICO

Population

Isolated aortae from male and female rats (including castrated males treated with oestradiol, and sexually-immature rats)

Intervention

Exposure to Mg2+-free (0 mM) and low-Na+ (84 mM) media

Comparator

Normal media, or comparison between sexes and endothelium-intact vs denuded preparations

Outcome

Tension development (basal tone)surrogate

Sex differences in vascular smooth muscle tone in response to Mg2+ and Na+ depletion are endothelium-dependent and may be regulated by oestradiol, potentially explaining female protection against ischaemic diseases pre-menopause.

Cite This Study

Bella T. Altura (1992) studied this question. Mg2+ withdrawal and Na+ reduction vs. Female rats / normal media was evaluated on Tension development in isolated aortae. Mg2+ withdrawal and Na+ reduction induced significant increases in basal tone in intact aortae of male rats but not female rats, suggesting female sex hormones modify endothelial functions.

synapsesocial.com/papers/6a9edfa33b2475de876f0dc1 https://doi.org/10.1111/j.1476-5381.1992.tb14250.x

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Implication

These animal findings should not change practice; hypothesis-generating for oestradiol-mediated endothelial protection against human ischaemic disease.

Endothelial‐dependent sexual dimorphism in vascular smooth muscle: role of Mg2+ and Na+

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Endothelial‐dependent sexual dimorphism in vascular smooth muscle: role of Mg2+ and Na+

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider