Effects of experimental irradiation on stromal vessels
Loading...
Date
1998-11-07
Authors
Sabanayagam, M. Indran
Journal Title
Journal ISSN
Volume Title
Publisher
University of Peradeniya
Abstract
Radiation damages both normal and abnormal tissues. Radiation therapy for
malignant disease therefore, produce side effects as a necessity. Signs such as altered
bowel activity and dry mouth are two common side effects of irradiation treatment and if
severemay interfere with the treatment schedule. The severity of these signs is variable and
subjective and is largely due to damage to the intestines and salivary glands. The exact
mechanisms underlying the causation of the signs are not understood fully. Early
experimental studies attributed these effects to cytotoxic injury caused by irradiation.
However, subsequent studies addressing functional impairments have shown that the
structures in the stroma such as blood vessels and nerves also contribute to the
developmentof undesirable side effects. This study therefore, aims to investigate the effect
of irradiation on the structure of the stromal blood vessels, of the small intestine and the
salivary glands. Techniques of light microscopy, scanning electron microscopy and
transmission electron microscopy will be used for structural observations.
Methodology: Three groups of BALB C male mice, group 1 -- control, group 2 --
sham control and group 3 -- experimental. Groups 1 and 2 had 24 mice, group 3 had 36
mice, each weighing 30 grams. Twenty-four mice from group 3 were exposed to a single
doseof 15 Gray, whole body gamma irradiation. The remaining twelve mice were exposed
to a single dose of 15 Gray gamma radiation to the head and neck region. The radiation
wasdelivered from mega volt, Cobalt 60, radiotherapy unit. The mice were killed 18 hours
and 72 hours after the radiation exposure. The jejunum was removed from twelve out of
the twenty-four mice exposed to whole body irradiation. The tissue was then processed for
resin histology and ultrastructure. The remaining twelve mice were injected with Mercox
resin to obtain vascular casts. The casts were processed for scanning electron microscopy.
The submandibular salivary glands were dissected out from mice exposed to head and neck
irradiation. These tissues were also processed for resin histology and ultrastructure.
Light microscopy of both jejunum and submandibular salivary glands, showed
dilated blood vessels. Endothelial cells were granular and their orientation appeared
disordered. The severity of damage increased with advancement of time. Ultrastructural
observations confirmed endothelial damage. The jejunal resin casts also showed capillary
dilatation in the irradiated samples. The capillary architecture followed structural changes
of the overlying villus.
This study confirms, that the stromal blood vessels are dilated after irradiation.
Vascular endothelial cells are also damaged.
Description
Keywords
Irradiation , Stromal Vvessels , Health Sciences
Citation
Proceedings & Abstracts of the Annual Research Sessions,1998,University of Peradeniya, peradeniya, Sri Lanka, pp 38