advertisement
Abstract #6687 Published in IGR 4-1
Effects on carbogen gas to the anterior choroidal blood flow in rats
Zhou Q; Qiu Y; Gao CChinese Ophthalmic Research 2001; 19: 503-506
OBJECTIVE: To determine the effects of systemic hyperoxia and hypercapnia on anterior choroidal blood flow in anesthetized rats, during pure oxygen (100% O2) or carbogen (95% O2 + 5% CO2) breathing. METHOD: Using laser Doppler flowmetry, the blood flow from the anterior choroid in urethane-anesthetized adult rats was measured continuously. After basal the choroidal blood flow had become stable in ambient room air breathing, experimental gas (oxygen or carbogen) was given to replace the room air in the sealed cabin. When the experimental gas had replaced the room air completely, choroidal blood flow was recorded at 20 minutes. At the end of experimental gas breathing, blood-gas analyses from the descending aorta were obtained to evaluate the effects of breathing. RESULTS: 1. Compared with ambient room air breathing, the choroidal blood flow increased during carbogen breathing (p < 0.01), but was not altered by pure O2 breathing (p > 0.05). 2. Although at hemoglobin oxygen saturation level (SaO2), the partial pressure of oxygen (PO2) was increased by pure O2 and carbogen breathing, there was no difference between pure O2 and carbogen breathing. Compared with room air breathing, partial pressure of carbon dioxide (PCO2) was increased after carbogen breathing (p < 0.01), whereas it decreased after pure O2 breathing (p < 0.01). CONCLUSIONS: 1. Carbogen can increase anterior choroidal blood flow in rats, and it can provide better oxygenation compared with pure O2. 2. The anterior choroidal blood flow in rats is not sensitive to the concentration of O2 in breathing gas, whereas the concentration of CO2 can influence choroidal blood flow remarkably.
Dr. Q. Zhou, Department of Ophthalmology, Affiliated Hospital of Qingdao University, Qingdao 266003, China
Classification:
5 Experimental glaucoma; animal models
6.11 Bloodflow measurements (Part of: 6 Clinical examination methods)
