Figure 2

A, cell cultures were grown for 28 days without any treatment (lane 1) or from day 14 of the culture onwards for a further 14 days in the presence of cyclosporin A (500 ng ml⁻¹) (lane 2) or the Ca²⁺ ionophore A23187 (4 × 10⁻⁷m) (lane 3) or cyclosporin A and Ca²⁺ ionophore (lane 4). Other cultures were electrostimulated (1 Hz for 15 min, stimulus duration 2.5 ms, followed by a pause of 30 min) (lane 5) or electrostimulated and treated with cyclosporin A (lane 6) from day 14 onwards for a further 14 days. B, cell cultures were grown for 16 days without any treatment (lane 1) or from day 14 of the culture onwards or a further 2 days in the presence of cyclosporin A (500 ng ml⁻¹) (lane 2) or Ca²⁺ ionophore (4 × 10⁻⁷m) (lane 3) or cyclosporin A and Ca²⁺ ionophore (lane 4). Total RNA (20 mg) was isolated from control and treated cultures at the time points indicated, fractionated on a 1.2 % formaldehyde agarose gel, and transferred to nitrocellulose. The blots were hybridized with the ³²P-labelled 3′ terminal Hin fI fragment of MHCI cDNA or an 18S rDNA probe. The positions of 18S rRNA (1.9 kb) and 28S rRNA (4.8 kb) on the ethidium bromide-stained gel are indicated.