Biju,M P; Paulose,C S(Department of Biotechnology, September 27, 1997)
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Abstract:
Kinetic parameters of brain glutamate dehydrogenase (GDH) were compared in the brain
stem, cerebellum and cerebral cortex of three weeks and one year old streptozotocin (STZ)
induced four day diabetic rats with respective controls. A single intrafemoral dose of STZ
(60mg/Kg body weight) was administered to induce diabetes in both age groups. After four days
the blood glucose levels showed a significant increase in the diabetic animals of both age groups
compared with the respective controls. The increase in blood glucose was significant in one year
old compared to the three weeks old diabetic rats. The Vmm of the enzyme was decreased in all
the brain regions studied, of the three weeks old diabetic rats without any significant change in
the Km. In the adult the Vmax of GDH was increased in cerebellum and brain stem but was
unchanged in the cerebral cortex. The K. was unchanged in cerebellum and cerebral cortex but
was increased in the brain stem. These results suggest there may be an important regulatory role
of the glutamate pathway in brain neural network disturbances and neuronal degeneration in
diabetes as a function of age.
Paulose,C S; Peeyush, K T; Anju, T R(Springer Science+Business Media, LLC 2009, 2009)
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Abstract:
Hypoxia in neonates can lead to biochemical
and molecular alterations mediated through changes in
neurotransmitters resulting in permanent damage to brain.
In this study, we evaluated the changes in the receptor
status of GABAA in the cerebral cortex and brainstem of
hypoxic neonatal rats and hypoxic rats supplemented with
glucose and oxygen using binding assays and gene
expression of GABAAa1 and GABAAc5. In the cerebral
cortex and brainstem of hypoxic neonatal rats, a significant
decrease in GABAA receptors was observed, which
accounts for the respiratory inhibition. Hypoxic rats sup-
plemented with glucose alone and with glucose and oxygen
showed, respectively, a reversal of the GABAA receptors,
andGABAAa1 and GABAAc5 gene expression to control.
Glucose acts as an immediate energy source thereby
reducing the ATP-depletion-induced increase in GABA
and oxygenation, which helps in encountering anoxia.
Resuscitation with oxygen alone was less effective in
reversing the receptor alterations. Thus, the results of this
study suggest that reduction in the GABAA receptors
functional regulation during hypoxia plays an important
role in mediating the brain damage. Glucose alone and
glucose and oxygen supplementation to hypoxic neonatal
rats helps in protecting the brain from severe hypoxic
damage.
Ani Das, V; Savitha,B; Paulose,C S(Department of Biotechnology, April 4, 2006)
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Abstract:
purpose of this study was to investigate the
role of brain al-adrenergic receptor binding in the rat model
of pancreatic regeneration using 60-70% pancre:dectorny.
The a, -adrenergic receptors kinetics was studied in the
cerebral cor:cx and brain stem of sham operated . 72 It pan-
crea(ectoinised and 7 days pancreatectomised rats. Scar
chard analysis with I `I I lprazocin in cerebral cartes and brain
stein showed a significant decrease (/' < 0.01). (P < 0.05)
in maximal binding ( 1),,,,,) with it significant decrease
(P < 0.001 ), ( P < 0.01) in the K,,in 72 It pancreatecto-
raised rats compared with sham , respectively . Competition
analysis in cerebral cortex and brain stem showed it shift in
affinity during pancreatic regeneration . The sympathetic
activity was decreased as indicated by the significantly de-
increased norepinephrine level in the plasma (P < 0.001),
cerebral cortex (P < 0.01) and brain stem (P < 0.001) of
72 h pancreatectomised rats compared to sham . Thus, from
our results it is suggested that the central a, -adrenergic
receptors have a functional role in the pancreatic regenera-
Lion mediated through the sympathetic pathway.
Sulaiman,Pyroja; Binoy,Joseph; Paulose,C S(Department of Biotechnology, December 5, 2006)
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Abstract:
In the present study, serotonin 2C (5-HT2c) receptor binding parameters in the brainstem and cerebral cortex were investigated during
liver generation after partial hepatectomy (PH) and N-nitrosodiethylamine (NDEA) induced hepatic neoplasia in male Wistar rats. The
serotonin content increased significantly (p<0.01) in the cerebral cortex after PH and in NDEA induced hepatic neoplasia. Brain stem
serotonin content increased significantly (p<0.05) after PH and (p<0.001) in NDEA induced hepatic neoplasia. The number and affinity of
the 5-HT2c receptors in the crude synaptic membrane preparations of the brain stem showed a significant (p<0.001) increase after PH and in
NDEA induced hepatic neoplasia. The number and affinity of 5-HT2c receptors increased significantly (p<0.001) in NDEA induced hepatic
neoplasia in the crude synaptic membrane preparations of the cerebral cortex. There was a significant (p<0.01) increase in plasma
norepinephrine in PH and (p<0.001) in NDEA induced hepatic neoplasia, indicating sympathetic stimulation. Thus, our results suggest that
during active hepatocyte proliferation 5-HT2c receptor in the brain stem and cerebral cortex are up-regulated which in turn induce hepatocyte
proliferation mediated through sympathetic stimulation.