Peripheral arterial chemoreceptors and hypertension

Area of Science:

• Cardiovascular Physiology
• Respiratory Physiology
• Nephrology

Background:

• Essential hypertension is characterized by resting hyperventilation and pronounced cardiorespiratory responses to hypoxia/hyperoxia.
• Peripheral arterial chemoreceptors are implicated in these responses in essential hypertension, but not in secondary (renal) hypertension.
• Carotid bodies, containing these chemoreceptors, show structural and biochemical changes in various hypertension models.

Purpose of the Study:

• To review carotid body structure and function in animal models and human hypertension.
• To investigate the link between carotid body alterations and functional overactivity in hypertension.
• To differentiate findings across primary, secondary, and experimental hypertension.

Main Methods:

• Review of morphological, morphometrical, and biochemical studies on carotid bodies.
• Analysis of functional studies in human and animal hypertension models.
• Comparison of findings in essential (primary) and secondary (renal) human hypertension.

Main Results:

• Carotid bodies exhibit altered structure and catecholamine content in hypertension.
• Observed alterations vary significantly between different hypertension types and models.
• A definitive link between carotid body morphology/biochemistry and functional overactivity is not consistently established.
• Some changes are attributed to elevated blood pressure, others to systemic disease, and some to genetic factors independent of blood pressure.

Conclusions:

• Carotid body function and structure are modified in hypertension, particularly in essential hypertension.
• The precise role and causality of these carotid body changes in hypertension pathogenesis require further elucidation.
• Distinguishing between pressure-induced, disease-related, and genetic alterations is crucial for understanding carotid body involvement in hypertension.