Table 5.

Effects of Feed Restriction on Select Endpoints in the Pubertal Female and Male Assays: Terminal Body Weight, Age at Puberty Onset, and Organ Weights

	Laws et al. (2007)	Laws et al. (2007)	Laws et al. (2000)	Laws et al. (2007)	Laws et al. (2007)
Female pubertal assay parameters	Change from control	Change from control	Change from control	Change from control	Change from control
Strain	Wistar	Wistar	Wistar	Wistar	Wistar
Sample size (n)	13	13	7–8	13	13
Age at start	22	22	22	22	22
Age at termination	41–42	41–42	41	41–42	41–42
Terminal bwt decrease	−2.1%	−4.6%	−8.6%	−12.1%	−18.9%
Age at vaginal opening (VO) (difference in days)	+0.3	−0.4	+1.6	+1.0	+1.5
Body weight at VO	+1.7%	−2.8%	−4.9%	−2.9%	−9.1%
No. of 4–5 day cycles (monitored: VO + 15 days)	NA	NA	−40.7%a	NA	NA
Pituitary	−2.8%	−2.6%	−16.3%	−13.3%	−21.6%
Adrenal	−2.5%	−7.1%	−1.0%	−13.6%	−17.0%
Liver	−0.7%	−13.4%	−5.1%	−16.8%	−29.5%
Kidneys	−2.7%	−7.4%	−7.5%	−13.4%	−20.8%
Ovaries	−6.7%	−3.3%	−11.4%	−21.7%	−31.7%
Uterus with fluid	−10.3%	−18.7%	−25.1%	−13.7%	−32.1%
Uterus without fluid	−3.2%	−6.0%	−12.6%	−10.8%	−28.3%
T4	+13.5%	+4.7%	−0.5%	−8.6%	−9.7%
TSH	+9.0%	−16.3%	+35.3%	−17.5%	−24.5%

	Laws et al. (2007)	Laws et al. (2007)	Laws et al. (2007)	Marty et al. (2003)b	Stoker et al. (2000)	Laws et al. (2007)
Male pubertal assay parameters	Change from control	Change from control	Change from control	Change from control	Change from control	Change from control
Strain	Wistar	Wistar	Wistar	CD	Wistar	Wistar
Sample size (n)	13	13	13	12	10c	13
Age at start	23	23	23	23	23	23
Age at termination	53–54	53–54	53–54	52	53	53–54
Terminal bwt decrease	1.8%d	5.9%d	9.0%d	11.3%	15.0%	19.2%d
Age at preputial separation (PPS) (difference in days)	−0.5	+0.3	−1.4	+1.8e	+2.1f	−0.1
Body weight at PPS	+1.2%	−1.5%	−11.6%	−5.4%	−13.4%	−16.5%
Pituitary	−5.1%	−12.8%	−17.4%	NA	NA	−23.4%
Adrenals	−17.6%	11.6%	−18.5%	NA	NA	−26.8%
Liver	−8.8%	−14.5%	−22.0%	NA	NA	−32.8%
Kidneys	−6.9%	−11.5%	−15.6%	NA	NA	−27.1%
Seminal vesicles with fluid	+17.3%	−2.7%	−11.4%	−10.5%	−55.2%	−30.7%
Ventral prostate	+10.7%	−6.7%	−12.6%	−11.4%	−29.2%	−23.3%
Epididymis (left)	+0.4%	−3.6%	−3.2%	−8.8%g	NDh	−10.4g
Epididymis (right)	NA	NA	NA			NA
Testis (left)	+2.1%	−1.4%	−2.1%	−4.6%i	NDj	−4.9%
Serum testosterone	+42.9%	−31.1%	+43.5%	NA	+9.5%	−5.0%
Serum T4	−3.2%	−14.4%	−23.2%	NA	+16.6%	−25.8%
Serum TSH	−10.9%	+1.4%	−15.2%	NA	−17%	−31.2%

NA, not applicable; endpoint not measured.

Bold type indicates changes in body weights, age at preputial separation, organ weights, or hormone concentrations that were statistically significant due to feed restriction and decreased body weights.

^aNo. of 4–5 day cycles from VO to 15 days was 2.7 in ad libitum fed control animals versus 1.6 in feed-restricted animals.

^bValues derived from animals necropsied on PND 52, the time point closest to the current study necropsy on PND 53.

^cn = 10 in the feed-restricted group, whereas n = 24 in the ad libitum fed control group.

^dBody weight differential on PND 53, although rats were euthanized on PND 53–54.

^eBody weight differential on PND 41 was approximately 13% relative to ad libitum fed controls.

^fBody weight differential on PND 43 was approximately 20% relative to ad libitum fed controls.

^gPercent change is for paired epididymal weights.

^hNo data available: significant difference in absolute epididymides weight reported, but data not shown.

ⁱPercent change is for paired testis weights.

^jNo data available: no significant difference in absolute testes weights reported, but data not shown.