title: Characterization of vasomotion in porcine retinal arterioles.
abstract: OBJECTIVE
  To characterize vasomotion in porcine retinal arterioles in vitro using isobaric (pressure myograph) and isometric (wire myograph) methods.
  
  
  METHODS
  Pressure myograph: 208 small porcine retinal arterioles (outer diameter 68 +/- 4 microm) were studied under isobaric conditions in a double-barrelled pipette system. Diameter changes of the arterioles were registered by video recordings. Wire myograph: 60 large porcine retinal arterioles (inner diameter 147 +/- 1.6 microm) were studied under isometric conditions in a small vessel myograph for force measurements.
  
  
  RESULTS
  The rates of success in initiating vasomotion were 7.2% using the pressure myograph and 43% using the wire myograph (p < 0.001). The small vessels studied under isobaric conditions oscillated with a frequency of 0.014 Hz and the episodes lasted 6.0 +/- 1.0 min, whereas the large vessels under isometric conditions oscillated with a significantly faster frequency of 0.043 Hz and lasted 32.1 +/- 4.9 min (p = 0.026).
  
  
  CONCLUSIONS
  Retinal vasomotion can be studied in vitro using both pressure myograph and wire myograph techniques. The wire myograph is superior to the pressure myograph in initiating and maintaining vasomotion in vitro.
authors.affiliation: Department of Ophthalmology, Arhus University Hospital, Denmark. ahe@akhphd.au.dk
authors.forename: Anders
authors.initials: A
authors.lastname: Hessellund
authors.forename: Peter
authors.initials: P
authors.lastname: Jeppesen
authors.forename: Christian
authors.initials: C
authors.lastname: Aalkjaer
authors.forename: Toke
authors.initials: T
authors.lastname: Bek
mesh_terms: D000818:Animals; D001160:Arterioles / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D009213:Myography; D012161:Retinal Artery / Q000502:physiology*; D013552:Swine; D014666:Vasomotor System / Q000502:physiology*