Culture of dispersed smooth muscle cells is known to cause rapid modulation from the contractile to the synthetic cellular phenotype. However, organ culture of smooth muscle tissue, with maintained extracellular matrix and cell-cell contacts, may facilitate maintenance of the contractile phenotype. To test the influence of culture conditions, structural, functional, and biochemical properties of rat tail arterial rings were investigated after culture. Rings were cultured for 4 days in the absence and presence of 10% FCS and then mounted for physiological experiments. Intracellular Ca(2+) concentration ([Ca(2+)](i)) after stimulation with norepinephrine was similar in rings cultured with and without FCS, whereas force development after FCS was decreased by >50%. The difference persisted after permeabilization with beta-escin. These effects were associated with the presence of vasoconstrictors in FCS and were dissociated from its growth-stimulatory action. FCS treatment increased lactate production but did not affect ATP, ADP, or AMP contents. The contents of actin and myosin were decreased by culture but similar for all culture conditions. There was no effect of FCS on calponin contents or myosin SM1/SM2 isoform composition, nor was there any appearance of nonmuscle myosin. FCS-stimulated rings showed evidence of cell degeneration not found after culture without FCS or with FCS + verapamil (1 microM) to lower [Ca(2+)](i). The decreased force-generating ability after culture with FCS is thus associated with increased [Ca(2+)](i) during culture and not primarily caused by growth-associated modulation of cells from the contractile to the synthetic phenotype.
Nordström, Ina,Forskargrupper vid Lunds universitet, Lund University Research Groups, Lunds universitet, Lund University, Kärlfysiologi, Vascular Physiology(SwePub:)
Malmqvist, Ulf,Lunds universitet, Lund University, Medicinska fakulteten, Faculty of Medicine, Institutionen för laboratoriemedicin, Department of Laboratory Medicine, Avdelningen för klinisk kemi och farmakologi, Division of Clinical Chemistry and Pharmacology(SwePub:)
Hellstrand, Per,Forskargrupper vid Lunds universitet, Lund University Research Groups, Lunds universitet, Lund University, Kärlfysiologi, Vascular Physiology(SwePub:)
Ingår i:American Journal of PhysiologyAmerican Physiological Society0002-9513277:1, s. 64-73