Heart failure is characterised by an increase in circulating catecholamine levels and alterations to the composition of the cardiac extracellular matrix (ECM). Despite this association little is known regarding how beta-adrenergic signalling modulates cardiac fibroblast (CF) – dependent remodelling of the ECM. The aims of this study were; i) to develop a method to isolate and maintain ovine CFs in culture, ii) determine if beta-adrenergic stimulation of CFs alters production of matrix metalloproteinases (MMPs) and their endogenous inhibitors, the tissue inhibitors of MMPs (TIMPs) and, iii) determine if chronic exposure to catecholamines alters CF expression of the beta2-adrenergic receptor (beta2-AR). Female Welsh Mountain ewes were killed by intravenous administration of 200 mg.kg-1 pentobarbitone sodium following 10,000 U of heparin. CFs were isolated from LV samples (~0.5g) by incubation with 1,000 U collagenase type II (Worthington) for 90 mins. Primary cultures were maintained at 37oC, 5% CO2. All experiments were carried out on cells at passage 4. Confirmation that isolated cells were CFs was carried out by immunostaining. At passage 4, 2×106 cells were seeded in 225 cm2 culture flasks, serum-starved for 24 h, and then media replaced with that containing either PBS, or 0.1 uM ISO for 48 h. After which, conditioned-media was collected, concentrated with centrifugal filters (Millipore) and assessed for MMP activity (gelatin zymography) and TIMP proteins (immunoblotting). Cell pellets were collected and membrane preparations obtained for measurement of levels of beta2-AR by immunoblotting. All cells isolated were positive for the fibroblast marker vimentin. Preliminary data (n=2 animals, minimum 3 repeats each) suggests that there is a trend towards an increase in MMP-2 activity with ISO compared to control. Furthermore there was also a trend towards an increase in protein levels of TIMP-1, TIMP-4 and membrane-bound beta2-AR with ISO. These initial experiments suggest that beta-adrenergic signalling may play a role in ECM remodelling by altering levels of key players in matrix degradation. Further studies will be carried out to investigate changes in these proteins with increasing doses of ISO, and whether these changes occur to a similar degree in CFs isolated from aged sheep (>8 years) where cardiac ECM remodelling is different to that in young animals (1). All procedures accord to The UK Animals (Scientific Procedures) Act, 1986.