Porcine and human relaxin bioactivity: bioactivities of porcine relaxin and human relaxin do not differ in mice and rats.

This study compares the bioactivity of porcine relaxin-1 to that of recombinant human relaxin-2 in mice and rats. The effects of the two hormone preparations on elongation of the mouse interpubic ligament and both the wet weight and the extensibility of the rat cervix were compared. No difference in bioactivity was detected between porcine relaxin-1 and recombinant human relaxin-2 in either rodent. Therefore, decisions concerning which of the two available forms of relaxin to employ for in vivo experimentation in mice and rats can be made without concerns about relative bioactivity.