Relaxin peptide hormones are protective during the early stages of ischemic stroke in male rats.

Relaxin peptide hormones are protective during the early stages of ischemic stroke in male rats. Endocrinology. 2014 Dec 2;:en20141676 Authors: Bergeron LH, Willcox JM, Alibhai FJ, Connell BJ, Saleh TM, Wilson BC, Summerlee AJ Abstract The pregnancy hormone relaxin protects tissue from ischemic damage. The ability of relaxin-3, a relaxin paralog, to do so has not been explored. The cerebral expression of these peptides and their receptors make them logical targets for study in the ischemic brain. We assessed relaxin peptide-mediated protection, relative relaxin family peptide receptor (RXFP) involvement and protective mechanisms. Sprague-Dawley rats receiving permanent or transient middle cerebral artery occlusions (pMCAO and tMCAO, respectively), were treated with relaxin peptides and brains collected for infarct analysis. Activation of the endothelial nitric oxide synthase (eNOS) pathway was evaluated as a potential protective mechanism. Primary cortical rat astrocytes were exposed to oxygen glucose deprivation (OGD), treated with relaxin peptides, and viability examined. Receptor involvement was explored using RXFP3 antagonist or agonist treatment and PCR. Relaxin and relaxin-3 reduced infarct size after pMCAO. Both peptides activated eNOS. As relaxin-3 has not previously been associated with this pathway and displays promiscuous RXFP binding, we explored receptor contribution. Expression of rxfp1 was greater than rxfp3 in rat bra...
Source: Endocrinology - Category: Endocrinology Authors: Tags: Endocrinology Source Type: research