Increased GABA B receptor subtype expression in the nucleus of the solitary tract of the spontaneously hypertensive rat.
Expression of GABA(B) receptor messenger RNA (mRNA) in the central nervous system was compared between the spontaneously hypertensive (SHR) and normotensive Wistar Kyoto (WKY) rat. Polymerase chain reaction (PCR) revealed all the isoforms except B1e in cortex, hypothalamus, and medulla oblongata. In the nucleus of the solitary tract (NTS) and ventrolateral medulla (VLM), the B1a-c and 1 g isoforms were present as well as B2. Real-time PCR detected significantly higher levels of B1a (p < 0.01) and B2 (p < 0.05) mRNA in the NTS of SHR compared to WKY. A significant increase in B1a expression (p < 0.05) was detected in VLM. Immunolabeling suggested presynaptic and postsynaptic expression of B1a, B1b, and B2 subtypes throughout the NTS, with significant differences in distribution patterns and labeling between subtypes and between SHR and WKY. These findings suggest that GABA(B) receptors expressed by neurones in NTS may be involved in cardiovascular regulation and that changes in GABA(B) mRNA expression levels may contribute to the hypertensive state in SHR.
Spary
Emma J
EJ
Division of Cardiovascular and Neuronal Remodelling, LIGHT Institute, Faculty of Medicine & Health, University of Leeds, Worsley Building, Leeds, LS2 9JT, UK. E.J.Spary@leeds.ac.uk
Maqbool
Azhar
A
Saha
Sikha
S
Batten
Trevor F C
TF
D017398:Alternative Splicing; D000818:Animals; D000918:Antibody Specificity; D001794:Blood Pressure; D001835:Body Weight; D015870:Gene Expression / Q000502:physiology; D006973:Hypertension / Q000378:metabolism / Q000503:physiopathology*; D007031:Hypothalamus / Q000166:cytology / Q000502:physiology; D007150:Immunohistochemistry; D008297:Male; D008526:Medulla Oblongata / Q000166:cytology / Q000502:physiology; D016253:Microscopy, Immunoelectron; D009474:Neurons / Q000502:physiology / Q000648:ultrastructure; D021122:Protein Subunits / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D018080:Receptors, GABA-B / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017552:Solitary Nucleus / Q000166:cytology / Q000502:physiology*
D021122:Protein Subunits; D012333:RNA, Messenger; D018080:Receptors, GABA-B