title: One Minute of Marijuana Secondhand Smoke Exposure Substantially Impairs Vascular Endothelial Function.
abstract: Despite public awareness that tobacco secondhand smoke (SHS) is harmful, many people still assume that marijuana SHS is benign. Debates about whether smoke-free laws should include marijuana are becoming increasingly widespread as marijuana is legalized and the cannabis industry grows. Lack of evidence for marijuana SHS causing acute cardiovascular harm is frequently mistaken for evidence that it is harmless, despite chemical and physical similarity between marijuana and tobacco smoke. We investigated whether brief exposure to marijuana SHS causes acute vascular endothelial dysfunction.
  
  
  
  We measured endothelial function as femoral artery flow-mediated dilation (FMD) in rats before and after exposure to marijuana SHS at levels similar to real-world tobacco SHS conditions. One minute of exposure to marijuana SHS impaired FMD to a comparable extent as impairment from equal concentrations of tobacco SHS, but recovery was considerably slower for marijuana. Exposure to marijuana SHS directly caused cannabinoid-independent vasodilation that subsided within 25 minutes, whereas FMD remained impaired for at least 90 minutes. Impairment occurred even when marijuana lacked cannabinoids and rolling paper was omitted. Endothelium-independent vasodilation by nitroglycerin administration was not impaired. FMD was not impaired by exposure to chamber air.
  
  
  
  One minute of exposure to marijuana SHS substantially impairs endothelial function in rats for at least 90 minutes, considerably longer than comparable impairment by tobacco SHS. Impairment of FMD does not require cannabinoids, nicotine, or rolling paper smoke. Our findings in rats suggest that SHS can exert similar adverse cardiovascular effects regardless of whether it is from tobacco or marijuana.
authors.affiliation: Cardiovascular Research Institute, University of California, San Francisco.
authors.forename: Xiaoyin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Cardiovascular Research Institute, University of California, San Francisco.
authors.forename: Ronak
authors.initials: R
authors.lastname: Derakhshandeh
authors.affiliation: Division of Cardiology, University of California, San Francisco Department of Cardiovascular Surgery & Electro-chemotherapy, China-Japan Friendship Hospital, Beijing, People's Republic of China.
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Liu
authors.affiliation: Cardiovascular Research Institute, University of California, San Francisco Division of Cardiology, University of California, San Francisco.
authors.forename: Shilpa
authors.initials: S
authors.lastname: Narayan
authors.affiliation: Division of Cardiology, University of California, San Francisco.
authors.forename: Pooneh
authors.initials: P
authors.lastname: Nabavizadeh
authors.affiliation: Division of Cardiology, University of California, San Francisco.
authors.forename: Stephenie
authors.initials: S
authors.lastname: Le
authors.affiliation: Cardiovascular Research Institute, University of California, San Francisco.
authors.forename: Olivia M
authors.initials: OM
authors.lastname: Danforth
authors.affiliation: Cardiovascular Research Institute, University of California, San Francisco.
authors.forename: Kranthi
authors.initials: K
authors.lastname: Pinnamaneni
authors.affiliation: Division of Cardiology, University of California, San Francisco Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco.
authors.forename: Hilda J
authors.initials: HJ
authors.lastname: Rodriguez
authors.affiliation: Division of Cardiology, University of California, San Francisco.
authors.forename: Emmy
authors.initials: E
authors.lastname: Luu
authors.affiliation: Division of Cardiology, University of California, San Francisco.
authors.forename: Richard E
authors.initials: RE
authors.lastname: Sievers
authors.affiliation: Division of Occupational and Environmental Medicine, University of California, San Francisco.
authors.forename: Suzaynn F
authors.initials: SF
authors.lastname: Schick
authors.affiliation: Cardiovascular Research Institute, University of California, San Francisco Division of Cardiology, University of California, San Francisco.
authors.forename: Stanton A
authors.initials: SA
authors.lastname: Glantz
authors.affiliation: Cardiovascular Research Institute, University of California, San Francisco Division of Cardiology, University of California, San Francisco Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco matt.springer@ucsf.edu.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Springer
mesh_terms: D000397:Air Pollution / Q000009:adverse effects*; D000818:Animals; D003326:Coronary Circulation / Q000187:drug effects; D004730:Endothelium, Vascular / Q000187:drug effects*; D005260:Female; D008385:Marijuana Smoking / Q000009:adverse effects*; D009569:Nitric Oxide / Q000378:metabolism; D005996:Nitroglycerin / Q000494:pharmacology; D016491:Peripheral Vascular Diseases / Q000209:etiology / Q000503:physiopathology; D017207:Rats, Sprague-Dawley; D012906:Smoke / Q000009:adverse effects*; D013997:Time Factors; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D012906:Smoke; D014665:Vasodilator Agents; D009569:Nitric Oxide; D005996:Nitroglycerin
keywords: artery; cannabis; endothelium; flow‐mediated dilation; marijuana; nitric oxide synthase; secondhand smoke; smoking; vasodilation