Table 2. MNIC yields (pmol/10⁸ cells) in rat BM suspensions and EC cultures.

MNIC yields	Wistar BM	Lewis BM	HUVEC*	bEnd.3*
basal NOS activity	38±16	38±6	395±40	1470±150
A23187-stimulated NOS activity	61±27	65±7	710±150	5330±600

^*Technical footnote: Since proper eNOS activity requires EC attachment and cell-cell contact, NO trapping was done on monolayers of HUVEC and bEnd.3 cells firmly attached to the bottom of a culture T₇₅ flasks, as described previously [21]. A single flask with ca 7.5×10⁶ confluent bEnd.3 cells has adequate signal to noise ratio [21], whereas HUVEC, having less eNOS, requires at least two flasks with total 15×10⁶ cells.