Cochlear blood flow in the rat. A methodological evaluation of the microsphere method

Area of Science:

• Physiology
• Cardiovascular Research
• Otolaryngology

Background:

• The microsphere method is used to quantify organ blood flow.
• Quantifying cochlear blood flow is challenging due to its small contribution to cardiac output and limited microsphere capture.
• Previous evaluations of the microsphere method have not fully addressed its application in small organs within small animals.

Purpose of the Study:

• To evaluate the feasibility of the microsphere method for quantifying cochlear blood flow in small animals.
• To assess the impact of physiological parameters on cochlear blood flow measurements in rats.

Main Methods:

• Investigated 130 rats of various ages with normal or arterial hypertension.
• Utilized the microsphere method to quantify blood flow.
• Evaluated the blood flow of 97 animals.

Main Results:

• Physiological parameters (PCO3, pH, PO2, mean arterial blood pressure) within typical anesthetized ranges did not significantly affect cochlear blood flow.
• The microsphere method proved feasible for measuring blood flow in the inner ear of small animals.

Conclusions:

• The microsphere method is a viable technique for studying cochlear blood flow in small animal models.
• The method's reliability is demonstrated despite common physiological variations in anesthetized rodents.