Fig 1. Effect of relaxin on heart rate and relaxin serum concentration.

(A) Rat relaxin was increased during pregnancy in transgenic and non-transgenic control rats. (B) Telemetrically measured heart rates. Relaxin treatment leads to an immediately increase in heart rate compared to vehicle treated rats. The arrow with plug indicates the observation of plug in the vagina, indicating day 1 of pregnancy. Start of treatment is indicated by the dotted line. (C) Human recombinant relaxin was present in the relaxin and not detectable (n.d.) in vehicle treated animals. All results are expressed as mean ± SEM of 5 animals per group, * p<0.05. (D) Illustration of absolute relaxin amount by the addition of endogenous and exogenous relaxin levels (demonstrated in A and C).