All of the rat monoclonal antibodies to type IV collagen a1 to a5 chains reacted well with bovine kidney (shown only for ai and a2; Fig. 4). The mouse monoclonal antibodies were not tested. Strong specific bands of approximately equal intensity were observed at 54 and 28 kDa for both a1(IV) and a2(IV). Staining for a3(IV) (53 kDa and a stronger band at 28 kDa), a4(IV) (54, 28, and 25 kDa), and a5(IV) (54 kDa and a strong band at 28 kDa) was observed. The type IV collagen a6(IV) antibody barely detected any positive bands. The presence of two monomers detected using type IV collagen a4 antibody is likely to be due to interchain, nonreducible, covalent cross-links as has been observed previously. The rat monoclonal antibodies to the a1 to a5 chains also reacted with nonreduced NCi domains (not shown) but more strongly with denatured products. flovent inhaler
Western blot analyses of dissected antral follicles showed that a1(IV) and a2(IV) were readily detectable at levels similar to that in kidney (Fig. 4). In comparison, the levels of the other type IV collagen chains a3, a4, or a5 were far lower in the follicles. This is consistent with the immunostaining patterns observed; by immunostaining, a high level of staining for a1 and a2 was present throughout the theca, whereas the a3 and a5 chains were observed only in the follicular basal laminae, and the thecal intracellular staining for a4 was very weak.