Naslov
Differential influence of vitamin C on the peripheral and cerebral circulation after diving and exposure to hyperoxia

Autori
Barak O, Caljkusic K, Hoiland R, Ainslie P, Thom S, Yang M, Jovanov P, Dujic Z

Izvornik
American journal of physiology. Regulatory, integrative and comparative physiology (0363-6119) 315 (2018), 4; 759-767

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
cerebral blood flow ; flow mediated dilation ; hyperoxia ; transcranial Doppler ultrasound
(cerebral blood flow ; flow-mediated dilation ; hyperoxia ; transcranial Doppler ultrasound)

Sažetak
We examined if the diving-induced vascular changes in the peripheral and cerebral circulation could be prevented by oral antioxidant supplementation. Fourteen divers performed a single scuba dive to eighteen meter sea water for 47 min. Twelve of the divers participated in a follow-up study involving breathing 60% of oxygen at ambient pressure for 47 min. Before both studies, participants ingested vitamin C (2 g/day) or a placebo capsule for 6 days. After a 2-wk washout, the study was repeated with the different condition. Endothelium- dependent vasodilator function of the brachial artery was assessed pre- and postintervention using the flow-mediated dilation (FMD) technique. Transcranial Doppler ultrasound was used to measure intracranial blood velocities pre- and 90 min postintervention. FMD was reduced by ∼32.8% and ∼21.2% postdive in the placebo and vitamin C trial and posthyperoxic condition in the placebo trial by ∼28.2% ( P < 0.05). This reduction in FMD was attenuated by ∼10% following vitamin C supplementation in the hyperoxic study ( P > 0.05). Elevations in intracranial blood velocities 30 min after surfacing from diving were reduced in the vitamin C study compared with the placebo trial ( P < 0.05). O2 breathing had no postintervention effects on intracranial velocities ( P > 0.05). Prophylactic ingestion of vitamin C effectively abrogated peripheral vascular dysfunction following exposure to 60% O2 but did not abolish the postdive decrease in FMD. Transient elevations of intracranial velocities postdive were reduced by vitamin C. These findings highlight the differential influence of vitamin C on peripheral and cerebral circulations following scuba diving, which are only partly mediated via hyperoxia.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija u biomedicini (prirodno područje, biomedicina i zdravstvo, biotehničko područje)

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