Sympathetic adrenergic blockade effects upon operantly conditioned blood pressure elevations in baboons

Area of Science:

• Physiology
• Pharmacology
• Behavioral Science

Background:

• Operant conditioning can modify physiological responses, including blood pressure.
• Sympathetic adrenergic nervous system activity is implicated in blood pressure regulation.

Purpose of the Study:

• To evaluate the role of sympathetic adrenergic nervous activity in operantly conditioned hypertension.
• To assess the effects of alpha- and beta-adrenergic blockers on conditioned hypertension in baboons.

Main Methods:

• Baboons were operantly conditioned to increase diastolic pressure.
• The effects of phentolamine, phenoxybenzamine (alpha-blockers), and propranolol (beta-blocker) were assessed.
• Changes in heart rate and blood pressure were measured during blockade and control sessions.

Main Results:

• Beta-blockade abolished tachycardia but did not reduce blood pressure increases.
• Alpha-blockade did not significantly attenuate blood pressure increases.
• Combined alpha- and beta-blockade significantly attenuated diastolic pressure increases, but significant elevations persisted.

Conclusions:

• The sympathetic adrenergic nervous system participates in operantly conditioned hypertension.
• Non-adrenergic factors are also involved in the development of conditioned hypertension.