Blockade of Rostral Ventrolateral Medulla (RVLM) Bombesin Receptor Type 1 Decreases Blood Pressure and Sympathetic Activity in Anesthetized Spontaneously Hypertensive Rats
Izabella S. Pinto, Aline A. Mourão, Elaine F. da Silva, Amanda S. Camargo, Stefanne M. Marques, Karina P. Gomes, James O. Fajemiroye, Angela A. da Silva Reis, Ana C. S. Rebelo, Marcos L. Ferreira-Neto, Daniel A. Rosa, André H. Freiria-Oliveira, Carlos H. Castro, Eduardo Colombari, Diego B. Colugnati, and Gustavo R. Pedrino
Bombesin (BBS) is an extract from a frog that is said to activate bombesin receptors as well as bombesin-like peptides. These are distributed in the central nervous system (CNS) as well as cardiac and respiratory systems. Administration of BBS is said to improve breathing as well as increase blood pressure, etc. Injection of BBS in normal rats is said to cause sympathoexcitation and administration of its antagonist decreased this response. The role of the rostral ventrolateral medulla (RVLM) in this response is not well understood even though it is said to regulate blood pressure and sympathetic tone. Therefore, this study was designed to understand whether an injection of BBS in the RVLM would affect cardiac responses and sympathoexcitation in normotensive and spontaneously hypertensive rats (SHR). Male Wistar normotensive as well as SHR were used to carry out this study. The results suggested that the injection of BBS into the RVLM led to sympathoexcitation with an increase in blood pressure in the normotensive as well as SHR. The use of an antagonist (blocking BBS type 1 receptor) decreased the mean arterial pressure and the resting sympathetic nerve activity in the SHR but not the normal tension rats. the results suggest that BBS can cause sympathoexcitation and maintain a higher level of mean arterial pressure in SHR by activating the RVLM.
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4889888/
Year: June 2016
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