Table II. Characterisation of 3T3F442A preadipocyte ecto-phosphatase activity.

Preadipocytes in Hepes-buffer described in Experimental Procedure but lacking Ca⁺⁺ and Mg⁺⁺, were incubated for 5 min at 37°C in the presence of the various agents before adding 5 μM [³³P]-LPA for 10 min, then water soluble [³³P] was measured and enzyme specific activity determined. Results represent means ± sem from three separated experiments.

	Specific Activity nmoles / min / mg of protein
Control	0.623 ± 0.049
Mg++ 2 mM	0.669 ± 0.046
NEM 2 mM	0.805 ± 0.071
Ca++ 1 mM	0.800 ± 0.078
EDTA 0.5 mM	0.683 ± 0.047