TIMP-1 mRNA and protein expression in the bovine CL. A) Northern blotting of TIMP-1 mRNA in early (E), mid (M), and late (L) stage CL is shown in the upper panel. The arrow indicates the 0.9 kb TIMP-1 transcript. The ethidium bromide stained 18S rRNA in corresponding luteal samples is shown in the lower panel. B) Changes in TIMP-1 mRNA, expressed as a densitometric ratio of TIMP-1 mRNA to 18S rRNA, are shown in the lower panel. Dissimilar letters denote significant difference at p < 0.05. C) A representative Western blot of TIMP-1 in early (E), mid (M), and late (L) stage CL. Conditioned medium of HT1080 cells (HT) was loaded in the first lane and was used as a positive control. D) TIMP-1 protein levels in different stages are presented as a ratio of band intensity in luteal samples to that in HT1080 conditioned medium. Dissimilar letters denote significant difference at p < 0.05.