Study type: Medical/biological study (experimental study)

Histological analysis of the effect of hyperthermia on normal rabbit hepatic vasculature med./bio.

By: Nishimura Y, Jo S, Akuta K, Masunaga S, Fushiki M, Hiraoka M, Takahashi M, Abe M
Published in: Cancer Res 1989; 49 (15): 4295-4297
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Aim of study (acc. to author)

To study the effects of hyperthermia on rabbit hepatic vasculature histologically. The liver is a good model for investigating the vascular changes following hyperthermia because it contains 3 different types of vessels.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 8 MHz
Exposure duration: 30 min

Exposure 1

Main characteristics
Frequency 8 MHz
Type
Exposure duration 30 min
Exposure setup
Exposure source
  • An array of 5 copper needles (10 mm long, 0.5 m in diameter) fixed to a plastic board 15 mm apart.
Setup A needle type interstitial RF heating applicator was inserted into the liver.
Additional info Examined area: 10 mm x 10 mm.
Parameters
Measurand Value Type Method Mass Remarks
power 200 W maximum - - -

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Investigated organ system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Vascular damage following hyperthermia continued up to 24 h after heating for the three types of vasculature. Central veins were the most thermosensitive followed by portal veins, whereas hepatic arterioles were the most thermoresistant. The temperature causing 50% vascular damage 24 h after heating was 41.5-42.5°C, 42.5-43.5°C, and 44-45°C for central veins, portal veins, and arterioles, respectively. This differential thermal responsiveness of hepatic vasculature may be attributed to the histological structure of the vessels.

Study character:

Study funded by