Substance P acting via the neurokinin-1 receptor regulates adverse myocardial remodeling in a rat model of hypertension. Int J Cardiol 2013 Oct 12;168(5):4643-51
Date
08/22/2013Pubmed ID
23962787Pubmed Central ID
PMC4043399DOI
10.1016/j.ijcard.2013.07.190Scopus ID
2-s2.0-84886395013 (requires institutional sign-in at Scopus site) 43 CitationsAbstract
BACKGROUND: Substance P is a sensory nerve neuropeptide located near coronary vessels in the heart. Therefore, substance P may be one of the first mediators released in the heart in response to hypertension, and can contribute to adverse myocardial remodeling via interactions with the neurokinin-1 receptor. We asked: 1) whether substance P promoted cardiac hypertrophy, including the expression of fetal genes known to be re-expressed during pathological hypertrophy; and 2) the extent to which substance P regulated collagen production and fibrosis.
METHODS AND RESULTS: Spontaneously hypertensive rats (SHR) were treated with the neurokinin-1 receptor antagonist L732138 (5mg/kg/d) from 8 to 24 weeks of age. Age-matched WKY served as controls. The gene encoding substance P, TAC1, was up-regulated as blood pressure increased in SHR. Fetal gene expression by cardiomyocytes was increased in SHR and was prevented by L732138. Cardiac fibrosis also occurred in the SHR and was prevented by L732138. Endothelin-1 was up-regulated in the SHR and this was prevented by L732138. In isolated cardiac fibroblasts, substance P transiently up-regulated several genes related to cell-cell adhesion, cell-matrix adhesion, and extracellular matrix regulation, however, no changes in fibroblast function were observed.
CONCLUSIONS: Substance P activation of the neurokinin-1 receptor induced expression of fetal genes related to pathological hypertrophy in the hypertensive heart. Additionally, activation of the neurokinin-1 receptor was critical to the development of cardiac fibrosis. Since no functional changes were induced in isolated cardiac fibroblasts by substance P, we conclude that substance P mediates fibrosis via up-regulation of endothelin-1.
Author List
Dehlin HM, Manteufel EJ, Monroe AL, Reimer MH Jr, Levick SPMESH terms used to index this publication - Major topics in bold
AnimalsDisease Models, Animal
Female
Gene Expression Regulation, Developmental
Heart Ventricles
Hypertension
Myocytes, Cardiac
Polymerase Chain Reaction
Pregnancy
Pregnancy, Animal
RNA, Messenger
Rats
Rats, Inbred SHR
Rats, Inbred WKY
Receptors, Neurokinin-1
Substance P
Ventricular Function, Left
Ventricular Remodeling