A novel system for transcutaneous application of carbon dioxide causing an "artificial Bohr effect" in the human body

• Published in: PloS one Vol. 6; no. 9; p. e24137
• Main Authors: Sakai, Yoshitada, Miwa, Masahiko, Oe, Keisuke, Ueha, Takeshi, Koh, Akihiro, Niikura, Takahiro, Iwakura, Takashi, Lee, Sang Yang, Tanaka, Masaya, Kurosaka, Masahiro
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 08.09.2011; Public Library of Science (PLoS)
• Subjects: Administration, Cutaneous; Adult; Animal experimentation; Animals; Biology; Blood flow; Bone surgery; Carbon dioxide; Carbon Dioxide - administration & dosage; Carbon Dioxide - pharmacokinetics; Data processing; Dissociation; Forearm; Gas permeation; Hand surgery; Health aspects; Hemoglobin; Hemoglobins; Hemoglobins - metabolism; Human body; Humans; Hydrogels; Hydrogen-Ion Concentration; I.R. radiation; In Vitro Techniques; In vivo methods and tests; Infrared spectra; Infrared spectroscopy; Ischemia; Magnetic resonance; Magnetic Resonance Spectroscopy; Male; Measuring instruments; Medical schools; Medicine; Metabolism; Muscle, Skeletal - metabolism; Near infrared radiation; Near infrared spectroscopy; Nuclear magnetic resonance spectroscopy; Orthopedics; Oxygen; Oxygen - metabolism; Oxyhemoglobins - metabolism; pH effects; Phosphorus; Physiology; Plastics; Rats; Rats, Sprague-Dawley; Skin; Skin - metabolism; Skin Absorption; Sodium; Spectroscopy; Spectrum analysis; Therapeutic applications; Tissues; Triceps surae muscle; University graduates; Young Adult; Japan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0024137

Carbon dioxide (CO(2)) therapy refers to the transcutaneous administration of CO(2) for therapeutic purposes. This effect has been explained by an increase in the pressure of O(2) in tissues known as the Bohr effect. However, there have been no reports investigating the oxygen dissociation of haemoglobin (Hb) during transcutaneous application of CO(2)in vivo. In this study, we investigate whether the Bohr effect is caused by transcutaneous application of CO2 in human living body. We used a novel system for transcutaneous application of CO(2) using pure CO(2) gas, hydrogel, and a plastic adaptor. The validity of the CO(2) hydrogel was confirmed in vitro using a measuring device for transcutaneous CO(2) absorption using rat skin. Next, we measured the pH change in the human triceps surae muscle during transcutaneous application of CO(2) using phosphorus-31 magnetic resonance spectroscopy ((31)P-MRS) in vivo. In addition, oxy- and deoxy-Hb concentrations were measured with near-infrared spectroscopy in the human arm with occulted blood flow to investigate O2 dissociation from Hb caused by transcutaneous application of CO(2). The rat skin experiment showed that CO(2) hydrogel enhanced CO(2) gas permeation through the rat skin. The intracellular pH of the triceps surae muscle decreased significantly 10 min. after transcutaneous application of CO(2). The NIRS data show the oxy-Hb concentration decreased significantly 4 min. after CO(2) application, and deoxy-Hb concentration increased significantly 2 min. after CO(2) application in the CO(2)-applied group compared to the control group. Oxy-Hb concentration significantly decreased while deoxy-Hb concentration significantly increased after transcutaneous CO(2) application. Our novel transcutaneous CO(2) application facilitated an O(2) dissociation from Hb in the human body, thus providing evidence of the Bohr effect in vivo.