Decreases in the expression of CGRP and galanin mRNA in central and peripheral neurons related to the control of blood pressure following experimental hypertension in rats.
Calcitonin gene-related peptide (alpha CGRP) and galanin (GAL) are peptides known to participate in central mechanisms of blood pressure control. Nonetheless, variations in the synthesis of the peptides in response to a hypertensive challenge are not well described, specially using a model, which allows acute and chronic analyses. In this study, we have employed in situ hybridization to analyse changes in mRNA expression of alpha CGRP and GAL in the nucleus tractus solitarii (NTS), hypothalamic paraventricular nucleus (PVN) as well as petrosal and nodose ganglia after aortic coarctation-induced hypertension in rats. Acute (2h) and chronic (3 and 7 days) analyses were performed in order to evaluate the involvement of both peptides in different periods of hypertension. The analysis of relative mRNA levels showed significant differences between sham-operated and aortic coarcted hypertensive rats. alpha CGRP mRNA expression was decreased 2h (40%) and 3 days (42%) in nodose and petrosal ganglia, respectively, after coarctation. No changes in CGRP mRNA signal were seen in the NTS and PVN in the analysed periods. GAL mRNA expression was decreased in the NTS (19%) and PVN (55%), 3 and 7 days, respectively, after coarctation-induced hypertension. No changes in GAL mRNA expression were observed in petrosal and nodose ganglia following aortic coarctation. Data suggest that alpha CGRP and GAL may participate in the mechanisms involved in the establishment/maintenance of hypertension induced by aortic coarctation. Acute changes might be involved with the adaptation to the hypertensive state, while changes at the chronic phase might be related to counteraction of hypertension.
Coelho
E F
EF
Department of Physiology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil.
Ferrari
M F R
MF
Maximino
J R
JR
Chadi
G
G
Fior-Chadi
D R
DR
D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D015740:Calcitonin Gene-Related Peptide / Q000235:genetics / Q000378:metabolism*; D019004:Galanin / Q000235:genetics / Q000378:metabolism*; D006973:Hypertension / Q000378:metabolism* / Q000503:physiopathology; D017403:In Situ Hybridization / Q000379:methods; D008297:Male; D009474:Neurons / Q000378:metabolism*; D009620:Nodose Ganglion / Q000378:metabolism; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology; D010525:Peripheral Nerves / Q000166:cytology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011921:Rats, Inbred WKY; D017552:Solitary Nucleus / Q000166:cytology; D013997:Time Factors
D012333:RNA, Messenger; D019004:Galanin; D015740:Calcitonin Gene-Related Peptide