title: Laser Doppler flowmetry in subepidermal tumours and in normal skin of rats during localized ultrasound hyperthermia.
abstract: Laser Doppler flowmetry has been applied to normal skin and to subepidermal tumours during localized ultrasound hyperthermia in the rat. In normal skin, 40 degrees C hyperthermia only induced a marginal increase in the red blood cell flux. Significant increases occurred after 20 min at 42 degrees C and after 4 min at 44 degrees C. During 44 degrees C hyperthermia maximum fluxes were reached after 24 min. Thereafter, the flow declined and finally approached preheating values. In contrast, in subepidermal tumours 40 degrees C hyperthermia on the average induced a slight decrease of the flux. During 42 degrees C hyperthermia a significant flow decrease was found after 40 min of heating. Following a transient increase in the laser Doppler flow during the heating-up period, 44 degrees C hyperthermia led to a significant impairment of the flux after 24 min. A total shutdown of RBC flux was observed in about 30 per cent of the tumours at 44 degrees C. Upon elevated tissue temperatures, pronounced inter-tumour variabilities in the time- and temperature-dependent changes of RBC flux were observed. Rhythmic oscillations of the RBC flux were found in some subepidermal tumours (0.40 +/- 0.05 cycles/min). Upon heating, these periodic flow variations slowed down significantly (0.20 +/- 0.04 cycles/min), whereas in normal skin the frequency of the flow fluctuations increased.
authors.affiliation: Department of Applied Physiology, University of Mainz, F.R. Germany.
authors.forename: P
authors.initials: P
authors.lastname: Vaupel
authors.forename: M
authors.initials: M
authors.lastname: Kluge
authors.forename: M C
authors.initials: MC
authors.lastname: Ambroz
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D002296:Carcinosarcoma / Q000098:blood supply / Q000628:therapy; D005260:Female; D006979:Hyperthermia, Induced / Q000379:methods*; D007834:Lasers; D008297:Male; D009374:Neoplasms, Experimental / Q000098:blood supply / Q000628:therapy*; D051381:Rats; D011919:Rats, Inbred Strains; D012513:Sarcoma, Experimental / Q000098:blood supply / Q000628:therapy; D012867:Skin / Q000098:blood supply*; D012878:Skin Neoplasms / Q000098:blood supply / Q000628:therapy*