What question did this study set out to answer?

To evaluate blood pressure and total peripheral resistance responses to alpha 1-adrenoceptor agonists during the development of hypertension and cardiovascular hypertrophy in spontaneously hypertensive rats.

January 1, 1994Journal of Hypertension

Arterial hypertrophy and pressor responsiveness during development of hypertension in spontaneously hypertensive rats

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Why the study?

Does alpha 1-receptor stimulation alter blood pressure and total peripheral resistance differently in spontaneously hypertensive rats compared to Wistar-Kyoto rats?

Population

Spontaneously hypertensive rats (SHR) aged 8-26 weeks

Comparison

Alpha 1-agonist phenylephrine and methoxamine… vs Age-matched Wistar-Kyoto (WKY) rats

Design

Preclinical

Follow-up

8-26 weeks of age

Authors

FLFrans H. H. LeenenPreventive Cardiology BYBaoxue YuanUniversity of Ottawa JTJames N. TsoporisSt. Michael's Hospital

Discussion

Member takes

Implication

Caution against extrapolating rat alpha-1 responses to humans; leaves open agonist-specific effects in hypertension.

Key Points

To evaluate blood pressure and total peripheral resistance responses to alpha 1-adrenoceptor agonists during the development of hypertension and cardiovascular hypertrophy in spontaneously hypertensive rats.
Measured blood pressure and total peripheral resistance responses to phenylephrine in spontaneously hypertensive rats (SHR) and age-matched Wistar-Kyoto (WKY) controls aged 8–26 weeks, both before and after ganglionic blockade.
Constructed cumulative dose-response curves to a second alpha 1-agonist, methoxamine, in 16-week-old SHR and WKY rats.
Hypertensive rats exhibited progressive hypertension accompanied by significant cardiac hypertrophy, mesenteric arterial bed hypertrophy, and elevated total peripheral resistance across all tested ages.
Phenylephrine-induced total peripheral resistance responses were significantly diminished in hypertensive rats compared to controls regardless of ganglionic blockade, while blood pressure responses were reduced significantly only without blockade.
Low doses of methoxamine produced enhanced blood pressure and total peripheral resistance responses in hypertensive rats compared to controls, an effect not observed at higher doses.

Structured PICO

Does alpha 1-receptor stimulation alter blood pressure and total peripheral resistance differently in spontaneously hypertensive rats compared to Wistar-Kyoto rats?

Population

Spontaneously hypertensive rats (SHR) aged 8-26 weeks

Intervention

Alpha 1-agonist phenylephrine (two doses) and methoxamine (dose-response curves at 16 weeks) before and after ganglionic blockade

Comparator

Age-matched Wistar-Kyoto (WKY) rats

Outcome

Responses of blood pressure and total peripheral resistance (TPR)surrogate

The development of hypertension in spontaneously hypertensive rats is associated with variable changes in blood pressure and TPR responses to alpha 1-receptor stimulation depending on the specific agonist used.

Cite This Study

Leenen et al. (1994) studied this question.

synapsesocial.com/papers/6a88ebc7cd9902a7ca1264d1 https://doi.org/10.1097/00004872-199401000-00005

Topics

Hypertension management

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Arterial hypertrophy and pressor responsiveness during development of hypertension in spontaneously hypertensive rats

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Topics

Arterial hypertrophy and pressor responsiveness during development of hypertension in spontaneously hypertensive rats

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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Topics

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