Figure 1
Total urinary 6-sulfatoxymelatonin production in ng per 24 h for F344 and HSD rats. Asterisk indicates P < 0.05. For each strain, n = 24 rats.
Figure 2
24-hour urinary 6-sulfatoxymelatonin excretion rhythms (ng/2 h) for F344 and HSD rats in SD (upper panel) and LD (lower panel). Values shown are means +/- SEM. Bars at the top of the figure indicate periods of light and dark for the SD and LD treatments, respectively. For each treatment group, n = 12 rats.
Figure 3
24-hour urinary 6-sulfatoxymelatonin excretion rhythms (ng/2 h) for two individual F344 rats (one in SD and one in LD) and two individual HSD rats (one in SD and one in LD). Bars at the top of the figure indicate periods of light and dark for the SD (upper panel) and LD (lower panel) treatments. The four rats selected for presentation were those with the lowest total 6-sulfatoxymelatonin excretion in their respective treatment groups.
Figure 4
Mean (+/- SEM) of body mass (a), paired testis mass (b), and paired seminal vesicle mass (c) of young HSD rats held in SD or constant dark (24D). Sample sizes: n = 13 in SD and 11 in 24D. NS indicates a lack of significant differences.
Figure 5
Mean (+/- SEM) of body mass (a), paired testis mass (b), and paired seminal vesicle mass (c) of young HSD rats in SD treated with saline injections (Sal) or melatonin (Mel). Sample sizes: n = 23 in Sal and 24 in Mel. NS indicates a lack of significant differences.