Study type: Medical/biological study (experimental study)

Brain enzyme histochemistry following stabilization by microwave irradiation. tech./dosim.

Published in: Histochem J 1988; 20 (6-7): 397-404

Aim of study (acc. to editor)

Microwave techniques in conjunction with other fixation methods can be used in pathology and neuroanatomy for improved staining and histochemical investigations. This study compares several biochemical and histochemical assays concerning the investigation of a broad range of enzymes in microwaved rat brains.

Background/further details

The studied enzymes were: alkaline phosphatase, acetylcholinesterase, 5'-nucleotidase, catalase, cytochrome oxidase, isocitrat-, malat-, lactat- , and succinate dehydrogenase. Brain microwave exposure occured after perfusing the rats and removing the brains. After microwave treatment the brains were homogenized or microtome sectioned for biochemical or histochemical investigation respectively.
Two different perfusion fluids were used followed by microwave exposure: physiological saline and 10% formalin. Non-pretreated material poses as control.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 2.45 GHz
Modulation type: CW
Exposure duration: 30 min
  • power: 150 W (at 50°C)

Exposure 1

Main characteristics
Frequency 2.45 GHz
Type
Exposure duration 30 min
Modulation
Modulation type CW
Exposure setup
Exposure source
  • Mile domestic oven 696
Chamber microwave was carried out in either saline or 10% formalin
Parameters
Measurand Value Type Method Mass Remarks
power 150 W - - - at 50°C

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

Biochemical outcome: all enzyme activity was lost after formalin-microwave treatment. After saline-microwave treatment the activity of acetylcholinesterase was increased. The activities of malat- and lactat dehydrogenase were not altered while activites of alkaline phosphatase, 5'-nucleotidase, succinat- and isocitrat dehydrogenase were reduced. The assays for the remaining enzymes were not performed.
Histochemical outcome: Analogous results were seen in the histochemical assays. The staining capabilities of alkaline phosphatase, lactat- and malat-dehydrogenase were reduced whereas acid phosphatase showed a moderate staining. The staining capabilities of all other enzymes were strong.
The saline-microwave technique allows a good histochemical as well as a good biochemical investigation of animal tissue.

Study character:

Study funded by