Chromatogram for SP profiling studies.

Standard chromatogram for profiling studies for SP (panel A) or SP(1-4) (panel B) and for affinity detection of SP(1-4) (panel C). A scheme showing optimal level of SP at 24 hours, which was reduced at 48 hours. Between 16 and 24 hours, NEP mRNA is induced, which is followed by the appearance of SP(1-4) at 48 hours (panel D).