M.Z. Azhakhmetova
B.N. Nurmukhambetova |
STRUCTURE OF COLON WALL EXPOSED TO CADMIUM INTOXICATION
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| Kazakh National Medical University, Almaty, Kasachstan
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Pollution of atmosphere, solid water by different toxic chemical compounds presents
a real danger for human and animal’s health. Cadmium is one of heavy metals
and their compounds, negatively affect organisms of human beings and animals.
Cadmium can penetrate into an organism through food. It accumulates in all tissues.
Nowadays there is a problem of searching methods and means for reducing toxic
influence of heavy metals. Objective of the study was to reveal the peculiarities
of colon mucous membrane structure when cadmium accumulated in an organism.
Methods of the study: experiments on rats were carried out according to “The
rules of conducting works with experimental animals”. All animals were
divided into 2 groups: the first-control one, included animals with intake
of a standard animal nutrition during 2.5 months. The second groups of animals
were fed with addition of CdCL2 in the dose of 1.5 mg per kg of mass during
2.5 months. Samples of colon were used as objects of study. For studying under
the electron microscope the samples of colon were fixed in 1% solution
of OSD4 on phosphate buffer (ph = 7.4), were dehydrated in spirit of ethyl of
higher concentration and concluded into epon. Semithin cuts of 1mkm thickness
were done from the obtained blocks, then they were colored by toluidin blue
and studied under the light microscope. Ultra thin cuts of 35-45 nm received
from the selected material on ZKB-8800 ultra tone were contrasted by saturated
aqueous solution of uranilacetine, citrate of tin and studied under the microscope
IEM1010. Results: on studying ultra structural composition of colon mucosa epithelium
colonocytes a day after administration of cadmium chloride there were revealed
many fine mitochondria with electron-compact matrix and a small number
of cristae. Cisterns of granular endoplasmatic reticulum were enlarged and consisted
of a small number of fixed ribosomes. There were observed the planed cisterns
of membranes of Goldgy complex. The number of secondary lysosomes increased.
A morphometric study of animals’ colonocytes showed not much difference
in values of volume densities of mitochondria and lysosomes and also densities
of fixed and free polysonic ribosomes after introducing cadmium. In 7
days after stopping cadmium exposure low concentration of mitochondrion with
a small number of cristae in colonocytes cytoplasmas was noted. Cisterns of
granular endoplasmatic reticulum remained enlarged and had a small number of
ribosomes. Cisterns of Goldgy complex were enlarged in size. The number of secondary
lysosomes was increased. The morphometric study of colonocytes revealed a reliable
reduction of values in volume densities of mitochondrion and granular endoplasmatic
reticulum and mitochondria. Values of quantitative density of the fixed
and free polysonal ribosomes were low. Volume density of secondary lysosomes
remained more than 2 times higher. The obtained data testifies a higher
development of destructive processes in colon mucosa epithelium colonocytes
in rats. However protein-syhthetic function of colonocytes remained reduced.
Conclusions: adding cadmium chloride to the nutrition of experimental animals
during 3 weeks, accumulation of cadmium by the body continually affects protein-synthetic
function of cells that was testified by lower quantitative densities of
the fixed and free polysomal ribosomes
