Age-dependent changes in 24-hour rhythms of catecholamine content and turnover in hypothalamus, corpus striatum and pituitary gland of rats injected with Freund's adjuvant

Table 2 Cosinor analysis on 24-h changes in striatal NE content and DA turnover in young and old rats injected with Freund's adjuvant or its vehicle 18 days earlier.

	Mesor	Amplitude	Acrophase (h, min)	Percent of rhythm
NE content
Young, Freund's adjuvant	40.1 ± 5.2	21.1 ± 3.6	17:15 ± 01:34	39 ± 4.5
Young, adjuvant's vehicle	49.6 ± 6.6	16.8 ± 2.1	06:29 ± 01:02^#	33 ± 5.6
Old, Freund's adjuvant	27.9 ± 4.1^*	8.5 ± 2.8^**	12:16 ± 02:01	27 ± 5.0
Old, adjuvant's vehicle	30.3 ± 5.4^*	12.5 ± 2.2	11:49 ± 02:21	50 ± 7.6
DA turnover
Young, Freund's adjuvant	0.11± 0.03	n.s.	n.s.	n.s.
Young, adjuvant's vehicle	0.19 ± 0.03^*	n.s.	n.s.	n.s.
Old, Freund's adjuvant	0.04 ± 0.03	n.s.	n.s.	n.s.
Old, adjuvant's vehicle	0.15 ± 0.05^#	n.s.	n.s.	n.s.

Shown are the means ± S.E.M. (n = 5–7/group). Mesor and amplitude values are expressed as pg/mg (NE content) or as DOPAC/DA ratio. Percent of rhythm defines the part of variation that could be explained by a cosine function in Cosinor. Asterisks designate significant differences (^*p < 0.05; ^**p < 0.01) as compared to their respective young counterparts; ^#p < 0.05 as compared to their respective Freund's adjuvant-treated counterparts (one-tailed Student's t test), n.s.: not significant daily changes in a one-way ANOVA.

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