Study: NCT05525416

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Sodium Nitroprusside
Description: A bolus injection of sodium nitroprusside will be given to lower blood pressure and evaluate baroreflex function.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Sodium Nitroprusside
Description: A bolus injection of sodium nitroprusside will be given to lower blood pressure and evaluate baroreflex function.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Phenylephrine Hydrochloride
Description: A bolus injection of phenylephrine will be given to raise blood pressure and evaluate baroreflex function immediately following the sodium nitroprusside infusion.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Phenylephrine Hydrochloride
Description: A bolus injection of phenylephrine will be given to raise blood pressure and evaluate baroreflex function immediately following the sodium nitroprusside infusion.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Phenylephrine Hydrochloride
Description: Investigators will give three incremental doses via brachial artery catheter to observe α1-adrenoreceptor mediated vasoconstriction. This will occur three times throughout the protocol.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Phenylephrine Hydrochloride
Description: Investigators will give three incremental doses via brachial artery catheter to observe α1-adrenoreceptor mediated vasoconstriction. This will occur three times throughout the protocol.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Norepinephrine
Description: Investigators will give three incremental doses via brachial artery catheter to observe adrenoreceptor activation. This will occur three times throughout the protocol.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Norepinephrine
Description: Investigators will give three incremental doses via brachial artery catheter to observe adrenoreceptor activation. This will occur three times throughout the protocol.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Isometric Handgrip and Post-Exercise Circulatory Occlusion
Description: Participants will perform 2 minutes of isometric handgrip at 30% maximal voluntary contraction followed by 2 minutes of post-exercise circulatory occlusion to assess the reactivity of the blood vessels to exercise and the metaboreflex.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Isometric Handgrip and Post-Exercise Circulatory Occlusion
Description: Participants will perform 2 minutes of isometric handgrip at 30% maximal voluntary contraction followed by 2 minutes of post-exercise circulatory occlusion to assess the reactivity of the blood vessels to exercise and the metaboreflex.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Rhythmic Handgrip
Description: Participants will perform 3 minutes of rhythmic handgrip at 25% maximal voluntary contraction to assess the reactivity of blood vessels to dynamic exercise.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Rhythmic Handgrip
Description: Participants will perform 3 minutes of rhythmic handgrip at 25% maximal voluntary contraction to assess the reactivity of blood vessels to dynamic exercise.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Cold Pressor Test
Description: Standardized sympathetic stressor involving submersion of the hand in ice-cold water for 3-minutes, aiming to elicit endogenous neurotransmitter release and blood pressure increases.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Cold Pressor Test
Description: Standardized sympathetic stressor involving submersion of the hand in ice-cold water for 3-minutes, aiming to elicit endogenous neurotransmitter release and blood pressure increases.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Propranolol Hydrochloride
Description: Local infusion via brachial artery catheterization will occur continuously for the remainder of the study. Propranolol is a beta-adrenergic antagonist and will allow investigation of the role of beta receptors in responses to various stressors. The above phenylephrine, norepinephrine, isometric handgrip, post-exercise circulatory occlusion, and rhythmic handgrip protocols will be repeated under propranolol infusion.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Propranolol Hydrochloride
Description: Local infusion via brachial artery catheterization will occur continuously for the remainder of the study. Propranolol is a beta-adrenergic antagonist and will allow investigation of the role of beta receptors in responses to various stressors. The above phenylephrine, norepinephrine, isometric handgrip, post-exercise circulatory occlusion, and rhythmic handgrip protocols will be repeated under propranolol infusion.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Phentolamine Mesylate
Description: Local infusion via brachial artery catheterization will occur continuously for the remainder of the study. Phentolamine is an alpha-adrenergic antagonist and will allow investigation the role of alpha receptors in responses to various stressors. It will be continuously infused with propranolol. The above phenylephrine, norepinephrine, isometric handgrip, post-exercise circulatory occlusion, and rhythmic handgrip protocols will be repeated under propranolol infusion.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Phentolamine Mesylate
Description: Local infusion via brachial artery catheterization will occur continuously for the remainder of the study. Phentolamine is an alpha-adrenergic antagonist and will allow investigation the role of alpha receptors in responses to various stressors. It will be continuously infused with propranolol. The above phenylephrine, norepinephrine, isometric handgrip, post-exercise circulatory occlusion, and rhythmic handgrip protocols will be repeated under propranolol infusion.