title: Suitable solutions for reconstituting the ultrasound contrast agent "Levovist" used in contrast echocardiogram: in vitro and in vivo evaluation of the influence of osmotic pressure.
abstract: OBJECTIVE
  To evaluate the influence of the osmotic pressure of solutions used for reconstituting the ultrasound contrast agent "Levovist" on the degree of video intensity of the enhancement and video intensity decay in contrast echocardiogram, we used 6 solutions with different osmotic pressures in both vitro and in vivo experiments.
  
  
  METHODS
  In the in vitro experiments, Levovist was reconstituted with 6 kinds of solutions with different osmotic pressures (Lactate Ringer's solution, 2.5%, 5%, 7.5%, and 20% glucose and distilled water) and peak video intensities and video intensity decay were measured. In the in vivo experiments, contrast echocardiography was performed in 7 adult volunteers, following the intravenous injections of Levovist, previously reconstituted with one of 2 solutions (5% glucose or distilled water).
  
  
  RESULTS
  In vitro, at peak time, Levovist reconstituted with either Lactate Ringer's solution, 2.5% glucose, 5% glucose, or distilled water had good peak video intensities. At 30 s after peak time, Levovist reconstituted with Lactate Ringer's solution had greater enhancement and less decay than the other 5 solutions (P<0.001). In vivo, at 180 heart beats after peak time, the video intensity decay with 5% glucose was greater than that with distilled water (150+/-13 dB, 123+/-25 dB, respectively, P<0.05).
  
  
  CONCLUSIONS
  In this study, among various (2.5-20%) glucose solutions, the stability of the microbubbles differed, depending on the degree of osmotic pressure of the respective solutions; 5% glucose was the best. However, overall, the most suitable solution for reconstituting Levovist, was Lactate Ringer's solution. These findings could lead to effective strategies for better contrast echocardiography using Levovist by changing the current solution of choice to Lactate Ringer's solution or 5% glucose.
authors.affiliation: Department of Cardiovascular Science and Medicine, Chiba University Graduate School of Medicine, Chiba City, Chiba, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Shiina
authors.forename: Nobusada
authors.initials: N
authors.lastname: Funabashi
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Teramoto
authors.forename: Masae
authors.initials: M
authors.lastname: Uehara
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takaoka
authors.forename: Yoko
authors.initials: Y
authors.lastname: Mikami
authors.forename: Akiyo
authors.initials: A
authors.lastname: Takahashi
authors.forename: Mariko
authors.initials: M
authors.lastname: Saito
authors.forename: Masao
authors.initials: M
authors.lastname: Daimon
authors.forename: Kwangho
authors.initials: K
authors.lastname: Lee
authors.forename: Miyuki
authors.initials: M
authors.lastname: Kawakubo
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Sekine
authors.forename: Maiko
authors.initials: M
authors.lastname: Takahashi
authors.forename: Rei
authors.initials: R
authors.lastname: Yajima
authors.forename: Akiko
authors.initials: A
authors.lastname: Tani
authors.forename: Issei
authors.initials: I
authors.lastname: Komuro
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000008:administration & dosage; D004339:Drug Compounding; D004452:Echocardiography / Q000379:methods*; D005260:Female; D005947:Glucose / Q000008:administration & dosage; D006801:Humans; D007275:Injections, Intravenous; D007552:Isotonic Solutions / Q000008:administration & dosage*; D008297:Male; D009997:Osmotic Pressure; D011134:Polysaccharides / Q000008:administration & dosage; D000077331:Ringer's Solution; D012995:Solubility; D014867:Water / Q000008:administration & dosage
chemical_list: D003287:Contrast Media; D007552:Isotonic Solutions; D011134:Polysaccharides; D014867:Water; C059891:SHU 508; D000077331:Ringer's Solution; D005947:Glucose