The impact of corticosteroids on hepatocytes ultrastructure experimental study in rats with electron microscopy

Abstract

Background and Aim: Corticosterstoids are drugs widely
used in common clinical practice.Their effect on liver morphology
and function is not fully elucidated.The aim of this
expenmental study is to investigate the impact of cortisol
on fasted rat hepatocytes, by means of electron microscopy.
Materials and Methods: Fifty male Wistar rats weighing
130-150gr were divided into two experimental groups: Group
I (N=30): Hydrocortisol 8mg/100gr i.p. and Group II (N-
20): Normal saline i.p. Animals were sacrificed 30 min and
180 min after injection and liver specimens were taken. According
to OsO4 -fixation protocol, ultra fine tissue sections
were obtained and stained for electron microscopy.
Results: The following findings were observed in >90% of
cortisol treated animals and were significantly more frequent
than in control group (P<0.05). A. At 30 min: Decondensation
of chromatin fibers was noticed, whereas nuclear
envelope and nucleoli remained almost intact. Endoplasmic
reticulum increased in size and complexity, as well as
the number of mitochondria. The number of lysosomes decreased.
B. At 180 min: Chromatin remained fully decondensated.
Large nucleoli were apparent within the nucleus.
The external membrane of the nuclear envelope was devoid
of ribosomes. Concerning all others cytoplasmic organelles,
no differences were noticed between different groups.
Conclusions: 1. Even late after cortisol administration, liver
parenchymal cells do not enter mitosis. Thus, a direct effect
of cortisol on hepatic regeneration is highly improbable.
2. Cortisol increases protein synthetic activity of hepatocytes,
by means of both chromatin decondensation and r-
RNA nucleolar production. 3. Increased cell metabolism is
assisted by adequate adaptation of intracellular energytransducing
systems.