studia universitatis babeş-bolyai biologia 2

STUDIA UNIVERSITATIS BABEŞ-BOLYAI, BIOLOGIA, XLV, 2, 2000
HISTOLOGICAL AND ULTRASTRUCTURAL STUDIES OF THE
RAT MYOCARDIUM AFTER A SINGLE THERAPEUTIC DOSE
OF CARBOPLATIN ADMINISTERED INTRAVENOUSLY
CRISTINA PAŞCA * , VIOREL MICLĂUŞ ** , CONSTANTIN CRĂCIUN*,
ERIKA KIS*, VICTORIA DOINA SANDU*, VERONICA CRĂCIUN*,
IONEL PAPUC** and CRISTIAN MUNTEANU ***
SUMMARY. – Carboplatin (Paraplatin) is an alkylating agent belonging to
the family of platinum-containing products, widely used in the chemotherapy
of many types of malignant diseases in humans. According to the previous
studies concerning its toxicity, this anticancer drug has a significant
myelotoxicity, nephrotoxicity and cardiotoxicity. Therefore, our investigations
intended to evaluate the histological and ultrastructural modifications induced
by a single therapeutic dose of Carboplatin (400 mg/m 2 body surface) in the
left ventricle of the rat myocardium. Light microscopy demonstrates that
Carboplatin induces many and obvious modifications consisting of the
appearance of a slight congestion, haemorrhage and a diffuse oedema which
was not correlated with the presence of a cellular infiltration. At the level of
many cardiac muscle fibres, some nuclear modifications appeared which
consisted of hyperthrophy, the presence of an increased number of nucleoli, a
peculiar arrangement of chromatin in groups. A few nuclei were round shaped
and very intensely stained. In addition, an obvious congestion and many
haemorrhages could be seen in the myocardium.
The ultrastructural alterations induced by this cytostatic consisted of the
appearance of an alteration of the vascular and sarcolemmal permeability,
correlated with a modified flux of electrolytes and water, leading to cell
swelling, disorganisation of the ultrastructure, especially at the periphery of the
myocytes, lysis of the sarcolemma and myofibrils, breaking of the Z-lines,
increasing of the interfibrillar spaces, swelling and degeneration of the
mitochondria. Besides, it could be noticed a massive oedema between the
myofibrils which determined the myocyte disorganisation. In the areas with an
advanced lysis, an obvious collagenous proliferation could be seen. All these
modifications, which already appeared 24 hours after the treatment, aggravated
progressively, but after 11 days started decreasing; at the end of the experiment
the granular myocardiosis correlated with myolysis microfocuses, congestion,
oedema and haemorrhages had just a zonal character.
* Babeş-Bolyai University, Department of Zoology, 3400 Cluj-Napoca, Romania.
E-mail: cpasca@biolog.ubbcluj.ro
** University of Agricultural Sciences and Veterinary Medicine, Department of Histology, 3400 Cluj-Napoca,
Romania
*** Elementary School Nr. 17, 3400 Cluj-Napoca, Romania