A nuclear magnetic resonance investigation of the upper airways in ferrets. I. Effects of histamine and methacholine.
Alterations induced in the upper airways of ferrets by intranasal provocation with methacholine (MC) and histamine (HS) were monitored using proton magnetic resonance imaging (MRI) and spin-spin relaxation rate (R2) measurements. Both MC and HS cause a significant increase in the MRI signal intensity and a decrease in R2 in the nasal turbinates. A dose-dependent response is observed for 20 to 315 nmol of HS, with a maximum increase in intensity of ca. 50% occurring above 80 nmol. A single unilateral challenge with MC yields a 62 +/- 3% increase in intensity. Control animals (saline-treated) show little change in image intensity. MC and HS cause decreases in the proton R2 by -27.0 +/- 5.5% and -17.2 +/- 4.3%, respectively. These data are indicative of an accumulation of fluid in the nasal airways. MRI provides an effective means to monitor changes in the nasal airways which occur as a result of pharmacological treatment.
Reo
N V
NV
Department of Biochemistry, Kettering-Scott Magnetic Resonance Laboratory, Wright State University, Dayton, Ohio.
Barnett
J K
JK
Neubecker
T A
TA
Alexander
M E
ME
Goecke
C M
CM
D000281:Administration, Intranasal; D000818:Animals; D005289:Ferrets / Q000502:physiology*; D006632:Histamine / Q000008:administration & dosage / Q000494:pharmacology*; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D016210:Methacholine Chloride / Q000008:administration & dosage / Q000494:pharmacology*; D012137:Respiratory System / Q000187:drug effects*; D014420:Turbinates / Q000187:drug effects
D016210:Methacholine Chloride; D006632:Histamine