Blood was collected and prepared as in Figure 1. (A) Whole-blood clotting times (mean ± SEM) were significantly shorter in male (filled squares) versus female (open circles) lit^m/+ mice not receiving GH (–pGH); *P < 0.01. Mean clotting times were significantly longer in male and female lit^m/m –pGH versus lit^m/+ –pGH mice; ***P < 0.001, ANOVA with Bonferroni’s post-hoc test. Clotting times were shortened to male lit^m/+ –pGH levels (and were significantly shorter than those in lit^m/+ –pGH females) in male and female lit^m/m mice receiving pGH (+pGH); ***P < 0.001. (B and C) WT male and female mice were given an identical dose of GH (28 μg/g body weight) or vehicle either divided into twice-daily doses over 7 days (pGH) (B) or as a continuous infusion (cGH) (C). The clotting times of female animals receiving pGH (WT +pGH) (B) were shortened relative to those of animals not receiving GH (WT –pGH), with no effect on male animals. Whole-blood clotting times (mean ± SEM) were significantly shorter in male (filled squares) than female (open circles) WT –cGH mice in both groups. The clotting times of male animals receiving cGH (WT +cGH) (C) were prolonged relative to those of animals receiving vehicle control (WT –cGH), with no effect on female animals. *P < 0.05, ***P < 0.001, ANOVA with Bonferroni’s post-hoc test.