Gamma-aminobutyric acid A receptor functional decrease in the hypothalamus during pancreatic regeneration in rats.
OBJECTIVE
In the present study, we investigated the alteration of gamma-aminobutyric acid A (GABAA) receptors in the hypothalamus of rats during pancreatic regeneration.


METHODS
Three groups of rats were used for the study: sham operated, 72 hours partially pancreatectomized, and 7 days partially pancreatectomized. The GABA receptor assay was performed by using the [H]GABA as ligand to the Triton X-100-treated membranes, and displacement with unlabeled GABA and [H]bicuculline binding to the GABAA receptors was assayed in Triton X-100-treated synaptic membranes and displacement with unlabeled bicuculline.


RESULTS
The GABA content in the brain regions and pancreas of the sham and experimental rat groups was quantified by displacement method. In the hypothalamus, the high-affinity GABAA receptor binding showed a significant decrease in maximal binding (P < 0.01) and equilibrium dissociation constant (P < 0.05) in 72 hours and 7 days partially pancreatectomized rats. The content of GABA has significantly decreased in the hypothalamus during the regeneration of pancreas.


CONCLUSIONS
This effect of GABAA receptors in hypothalamus suggests a regulatory role during active regeneration of pancreas that will have significance in insulin secretion.
Kaimal
Sankara Balarama
SB
Department of Biotechnology, Molecular Neurobiology and Cell Biology Unit, Centre for Neuroscience, Cochin University of Science and Technology, Cochin, India.
George
Kunnumelkudy Akash
KA
Paulose
Chiramadathikudiyil Skaria
CS
D000818:Animals; D001640:Bicuculline / Q000378:metabolism; D001667:Binding, Competitive; D015536:Down-Regulation; D018756:GABA Antagonists / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism*; D010179:Pancreas / Q000503:physiopathology* / Q000601:surgery; D010180:Pancreatectomy; D012333:RNA, Messenger / Q000378:metabolism; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar; D011963:Receptors, GABA-A / Q000235:genetics / Q000378:metabolism*; D012038:Regeneration; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013570:Synaptic Membranes / Q000378:metabolism; D013997:Time Factors; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D018756:GABA Antagonists; D012333:RNA, Messenger; D011963:Receptors, GABA-A; D005680:gamma-Aminobutyric Acid; D001640:Bicuculline