Figure 1

24-h changes in plasma prolactin levels of 11 days old male rabbit pups. Groups of 6–7 pups were killed by decapitation at 6 different time intervals throughout a 24 h cycle. Bar indicates scotophase duration. Results are the means ± SEM. ^a p < 0.01 vs. all time points. ^b p < 0.01 vs. 01:00 h, 05:00 h and 13:00 h, Tukey-Kramer's multiple comparisons test. For further statistical analysis, see text.