Micro-anatomical changes in the aorta, pulmonary trunk, and left ventricle of
Wistar rats were studied after the administration of streptozotocin. Twenty
adult Rattus norvegicus were randomly assigned into two groups (control and
diabetic) of ten rats each. Diabetes mellitus was experimentally induced in the
diabetic group of rats by daily intra-peritoneal administration of multiple doses
of 40 mg/kg streptozotocin dissolved in 0.1 M sodium citrate buffer for five
consecutive days. The control group was given the equivalent volume of citrate
buffer. The animals were monitored for four weeks after streptozotocin administration.
Post sacrifice, the left ventricle, aorta, and pulmonary trunk were
excised, weighed, and fixed by immersion in 10% formol saline. The tissues
were processed for paraffin embedding, and sections of 6 μm thickness were
produced and stained with H & E for general histological observations, and
Verhoeff-van Gieson elastic fibre stain to demonstrate elastic fibres in these
cardiovascular structures. The data obtained were analyzed with descriptive
and inferential statistics. Histopathological and morphometric examinations of
the stained sections showed a significant increase in the thickness of the tunica
intima of aorta (t = –7.49; df = 9; p < 0.05) and pulmonary trunk (t = –10.81;
df = 9; p < 0.05) in diabetic rats (14.59 ± 1.189 mm and 11.307 ± 0.863 mm,
respectively) when compared to that of the control group (3.62 ± 0.353 mm
and 3.22 ± 0.244 mm, respectively). In addition, the distribution of elastic and
collagen fibres was sparse in the hearts of the diabetic group when compared
to that of the control group. The findings of this study demonstrated that diabetes
mellitus might cause some alterations in the microanatomy of cardiovascular
structures
