Vol 68, No 2 (2009)
Original article
Submitted: 2012-02-06
Published online: 2009-02-25
Ultrastructural observations on the hypothalamic arcuate nuclei of aged rats in the fasting/refeeding model
J. Kubasik-Juraniec, N. Knap
Folia Morphol 2009;68(2):79-83.
Vol 68, No 2 (2009)
ORIGINAL ARTICLES
Submitted: 2012-02-06
Published online: 2009-02-25
Abstract
The arcuate nucleus of the hypothalamus (ARH) is involved in the control of
energy homeostasis. This is the first study on the ultrastructural response of ARH
neurons in aged rats after short-term fasting and subsequent refeeding. Male
Wistar rats (24 weeks old) were fasted for 48 or 96 hours and were then refed for
24 hours. The controls were normally fed. The rats received water ad libitum. In
both groups of fasting animals, we observed a rearrangement of the arcuate
rough endoplasmic reticulum (RER) and Golgi complexes to form membranous
whorls. Moreover, refeeding for 24 hours did not reverse this process. The RER
was frequently found to be well organized into lamellar bodies composed of
several cisternae. The membranous whorls were composed of concentric layers
of endoplasmic reticulum and Golgi complexes. In addition, multiform lipofuscin
granules were observed in close relationship with Golgi complexes and membranous
whorls. Lipofuscin granules within the neurons of the arcuate nucleus are
assumed to be a morphological manifestation of oxidative stress phenomena,
which are presumably implicated in the formation of membranous whorls in
both fasting and fasting/refed animals. This observation correlates with a significant
increase in 8-isoprostane serum levels in the fasting and fasting/refed animals
as compared to the fed control rats.
Abstract
The arcuate nucleus of the hypothalamus (ARH) is involved in the control of
energy homeostasis. This is the first study on the ultrastructural response of ARH
neurons in aged rats after short-term fasting and subsequent refeeding. Male
Wistar rats (24 weeks old) were fasted for 48 or 96 hours and were then refed for
24 hours. The controls were normally fed. The rats received water ad libitum. In
both groups of fasting animals, we observed a rearrangement of the arcuate
rough endoplasmic reticulum (RER) and Golgi complexes to form membranous
whorls. Moreover, refeeding for 24 hours did not reverse this process. The RER
was frequently found to be well organized into lamellar bodies composed of
several cisternae. The membranous whorls were composed of concentric layers
of endoplasmic reticulum and Golgi complexes. In addition, multiform lipofuscin
granules were observed in close relationship with Golgi complexes and membranous
whorls. Lipofuscin granules within the neurons of the arcuate nucleus are
assumed to be a morphological manifestation of oxidative stress phenomena,
which are presumably implicated in the formation of membranous whorls in
both fasting and fasting/refed animals. This observation correlates with a significant
increase in 8-isoprostane serum levels in the fasting and fasting/refed animals
as compared to the fed control rats.
Keywords
arcuate nucleus; fasting/refeeding; whorls; oxidative stress
Title
Ultrastructural observations on the hypothalamic arcuate nuclei of aged rats in the fasting/refeeding model
Journal
Folia Morphologica
Issue
Vol 68, No 2 (2009)
Article type
Original article
Pages
79-83
Published online
2009-02-25
Page views
465
Article views/downloads
1200
Bibliographic record
Folia Morphol 2009;68(2):79-83.
Keywords
arcuate nucleus
fasting/refeeding
whorls
oxidative stress
Authors
J. Kubasik-Juraniec
N. Knap
About this article