Expression of collagen type 1a1 and 3a1 isoforms in aortic adventitial fibroblast cultured from ovariectomized and intact Long Evans rats (LB715)

. The prevalence of cardiovascular disease is lower in premenopausal women when compared to equally aged men. Decreased arterial compliance may contribute to the increased risk. This reduced vascular compliance can be attributed to increases in adventitial collagen deposition in the postmenopausal state. The goal of this project was to determine if collagen type 1a1 and 3a1 are expressed differently in aortic fibroblasts cultured from an animal model of post‐menopausal physiology; surgically ovariectomized Long Evans rats and control animals with ovaries intact and subjected to a sham surgery. Fibroblasts were established in T‐25 flasks from 0.5‐1.5 mm sections of thoracic aorta isolated from three ovariectomized and control animals. Fibroblasts were grown for seven days in Dulbecco’s Modified Eagles Medium (DMEM) containing 15% FBS and then passed and cultured for 48 hours in DMEM containing 10% FBS. Immunodetection of the proteins desmin and vimentin was used to verify fibroblast identity. Prior to RNA extraction all cells were incubated for 72 hours in DMEM clear. After cDNA synthesis, the relative expression (∆∆C T ) of collagens 1a1 and 3a1 was determined using real‐time PCR and 18S as an endogenous control. From these runs it was determined that collagen 1a1 and 3a1 expression is 1.6 and 1.4 fold higher respectively in fibroblasts isolated from ovariectomized rats when compared to the control. This indicates that lack of ovarian hormones can lead to increased adventitial collagen expression, which may reduce arterial compliance. Studies focusing on the influence of hormones, such as relaxin, on collagen expression are underway. Grant Funding Source : Supported by NIH 1R15HL09343