Thyroid Hormone Stimulates g-Glutamyl Transpeptidase in the Developing Rat Cerebra and in Astroglial Cultures
IR@IICB: CSIR-Indian Institute of Chemical Biology, Kolkata
View Archive Info| Field | Value | |
| Title |
Thyroid Hormone Stimulates g-Glutamyl
Transpeptidase in the Developing Rat
Cerebra and in Astroglial Cultures
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| Creator |
Dasgupta, Asmita
Das, Sumantra Sarkar, Pranab K |
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| Subject |
Cell Biology & Physiology
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| Description |
. Hypothyroidism in the developing rat brain is associated
with enhanced oxidative stress, one of the earliest
manifestations of which is a decline in the level of glutathione
(GSH). To investigate the role of thyroid hormone
(TH) on GSH homeostasis, the effect of TH on gglutamyl
transpeptidase (gGT), the key enzyme involved
in the catalysis of GSH, was studied. Hypothyroidism
declined the speci.c activity of cerebral gGT at all postnatal
ages examined (postnatal day 1–20) with a maximum
inhibition of 42% at postnatal day 10. Intraperitoneal
injection of TH to 15-day-old rat pups increased
the speci.c activity of gGT by 25-30% within 4–6 hr.
Treatment of primary cultures of astrocytes by TH also
enhanced the speci.c activity of gGT by 30–40% within
4–6 hr. The induction of gGT by TH was blocked by
actinomycin D or cycloheximide. gGT is an ectoenzyme
that is normally involved in the catabolism of GSH
released by astrocytes. In the presence of the gGTinhibitor,
acivicin, GSH released in the culture medium
of astrocytes increased linearly for at least 6 hr and TH
had no effect on this accumulation pattern. In the
absence of acivicin, GSH content of the medium from
TH-treated cells was signi.cantly lower than that of
untreated controls due to activation of gGT by TH and
a faster processing of GSH. Because the products of
gGT reaction are putative precursors for neuronal GSH,
the activation of gGT by TH may be conducive to GSH
synthesis in neurons and their protection from oxidative
stress.
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| Date |
2005
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| Type |
Article
PeerReviewed |
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| Format |
application/pdf
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| Identifier |
http://www.eprints.iicb.res.in/1164/1/JOURNAL_OF_NEUROSCIENCE_RESEARCH%2C_82%2C_6_%2C_851%2D857[1].pdf
Dasgupta, Asmita and Das, Sumantra and Sarkar, Pranab K (2005) Thyroid Hormone Stimulates g-Glutamyl Transpeptidase in the Developing Rat Cerebra and in Astroglial Cultures. Journal of Neuroscience Research, 82 (6). pp. 851-857. |
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| Relation |
http://dx.doi.org/10.1002/jnr.20657
http://www.eprints.iicb.res.in/1164/ |
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