INFLUENCE OF DIFFERENT TYPES OF ANESTHESIA ON SKIN OXYGENATION AND ACTION OF TOPICALY APPLIED VASODILATOR

Abramović1 Zrinka, Šentjurc1 Marjeta, Kristl2 Julijana, Khan3 Nadeem, Swartz3 M Harold

1“Jožef Stefan” Institute, 2University of Ljubljana, Faculty of pharmacy, Ljubljana, Slovenia 3Department of Diagnostic Radiology, Dartmouth Medical School, Hanover, NH, USA.

Anesthesia can significantly affect tissue oxygenation and it is therefore an important factor to consider in the in vivo studies of partial oxygen pressure (pO2) in tissues1. For this purpose it is important to choose an optimal anesthetic that causes minimal changes in pO2, and ensure the stabile baseline values for longer period of time. In this work the influence of two general anesthetics, ketamine/xylazine (K/X) and isoflurane (IF) on skin pO2 has been investigated by EPR oximetry and their possible applications in in vivo studies of vasodilator benzyl nicotinate (BN) penetration into the skin have been evaluated. Balb C mice were anaesthetized and the hair from the back was removed. Particles of paramagnetic probe lithium phthalocyanine (LiPc) were inserted into the dermis of the skin. To obtain the physiological pO2 in mouse skin (baseline) the animals were anaesthetized by i.p. injection of K/X mixture or IF anesthetic (inhaled with 26% or 100% O2) and LiPc EPR spectral line-width was measured with time after anesthesia. When the baseline stabilized, preparation with 0.83 % BN was applied onto the skin and the EPR spectra were recorded for next 60 min. The measurements were performed on a Varian E-9 EPR magnet with a custom-built low-frequency microwave bridge (1.1 GHz) and a surface coil detector at optimal spectrometer settings.

Email: marjeta.sentjurc@ijs.si

Address: Jamova 39, 1000 Ljubljana, Slovenia