title: Unilateral administration of a drug into the lung of a small animal.
abstract: BACKGROUND
  The selective unilateral administration of drugs into a single lung of a rat is difficult because of the small airway diameter. Therefore, a simple method for unilateral administration into rat lung is needed.
  
  
  METHODS
  Rats were assigned to 1 of 2 groups according to the direction of the catheter used for drug administration. Anesthetized rats were intubated, and curved epidural catheters were rotated up to a maximum of 90 degrees toward the left lung (group L) or right lung (group R). Bronchial catheters were then inserted via a tracheal tube and fixed. Methylene blue (0.3 ml) was injected via the epidural catheter. Additionally, to compare survival rates, rats were assigned to one of two groups according to the drug administration route. In group T, bleomycin hydrochloride (20 mg/kg) in 0.3 ml of phosphate-buffered saline (PBS) was administrated into the lung intratracheally via a tracheal tube. In group B, the same dose of bleomycin was administrated into the lung intrabronchially via a bronchial catheter, targeting the left lung.
  
  
  RESULTS
  Gross examination revealed that targeted administration was 100% successful. Methylene blue was observed in the right lung of all rats in the R group and in the left lung of all rats in the L group. The survival rate was higher in group B than in group T.
  
  
  CONCLUSIONS
  The intrabronchial method offers an advantage over tracheal administration as it decreases mortality and allows the administration of a drug unilaterally into a single lung or into a localized area without the need for double-lumen tubes or more invasive procedures.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Paik Hospital, Inje University, Busan, Korea.
authors.forename: Soon Ho
authors.initials: SH
authors.lastname: Cheong
authors.forename: Young Il
authors.initials: YI
authors.lastname: Yang
authors.forename: Jie Yeon
authors.initials: JY
authors.lastname: Seo
authors.forename: Dong Hwa
authors.initials: DH
authors.lastname: Jun
authors.forename: Myoung Jin
authors.initials: MJ
authors.lastname: Ko
authors.forename: Kwang Rae
authors.initials: KR
authors.lastname: Cho
authors.forename: Sang Eun
authors.initials: SE
authors.lastname: Lee
authors.forename: Young Hwan
authors.initials: YH
authors.lastname: Kim
authors.forename: Se Hun
authors.initials: SH
authors.lastname: Lim
authors.forename: Jeong Han
authors.initials: JH
authors.lastname: Lee
authors.forename: Kun Moo
authors.initials: KM
authors.lastname: Lee