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. 2018 Nov 26;3(4):nzy093.
doi: 10.1093/cdn/nzy093. eCollection 2019 Apr.

Time Restriction of Food Intake During the Circadian Cycle Is a Possible Regulator of Reproductive Function in Postadolescent Female Rats

Tomoko Fujiwara  1 , Rieko Nakata  2 , Masanori Ono  3 , Michihiro Mieda  4 , Hitoshi Ando  5 , Takiko Daikoku  6 , Hiroshi Fujiwara  3
Affiliations

Time Restriction of Food Intake During the Circadian Cycle Is a Possible Regulator of Reproductive Function in Postadolescent Female Rats

Tomoko Fujiwara et al. Curr Dev Nutr. .

Abstract

Background: We previously reported that skipping breakfast is associated with menstrual disorders of female college students during postadolescent maturation.

Objective: In this study, we investigated the effects of meal timing during circadian cycle on the ovarian function using young female rats.

Methods: Considering that rats are nocturnally active, 8-wk-old female Wistar rats were classified into 3 groups: fed during the daytime only (nonactive phase), night-time only (active phase), or control group I (without time or calorie restriction, free access to a standard caloric diet, 20.0% protein, 62.9% carbohydrate, and 7.0% fat, 3.95 kcal/g) for 4 wk. The changes in body weight and frequency of ovulation in each group were evaluated by a weight scale and a vaginal smear, respectively. At the end of the period of dietary restriction, ovaries were removed, and the numbers of growing follicles (mean diameter >250 µm) and corpora lutea (>600 µm) were examined using hematoxylin-eosin-stained tissue sections. In addition, 8-wk-old female rats were fed only during the night-time for 4 wk under a 20%-reduced food supply of the control group II (without any restriction).

Results: In the daytime-fed group, the frequency and number of ovulations were significantly decreased compared with those in the control group I (P < 0.05), with a reduced body weight gain concomitant with about 20% of reduction in the daily food intake. In contrast, in the night-time-fed group, even when a 20% reduction in the daily food intake was loaded, their estrus cyclicity did not change despite significant reductions in weight gain and food intake compared with control group II.

Conclusion: These findings indicate that restricting food intake to the inactive phase impairs ovarian function in postadolescent female rats, suggesting that the timing of food intake during circadian cycle is one of the crucial factors interfering with the reproductive function.

Keywords: active phase; circadian rhythms; dietary restriction; ovarian function; postadolescent rat; weight gain.

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Figures

FIGURE 1
FIGURE 1
Evaluation of estrus cycle by a vaginal smear method. (A–C) Results in graphic form showing vaginal smear method and the estrus cycle. In (A), the stage of the estrus cycle was classified into 5 phases: I, proestrus; II, estrus; III, metestrus-1; IV, metestrus-2; V, diestrus using Giemsa staining. In (B) and (C), the transition from the proestrus phase (I) to estrus phase (II) or metestrus phase (III and IV) (gray arrows) was considered to be evidence of the occurrence of ovulation during the estrus cycle. In (C), the metestrus phase (III) on day 0 was not counted (white arrowhead), whereas the metestrus phase on day 28 was evaluated as evidence of ovulation (black arrowhead). Bars show 25 µm. (D) Experimental strategy for Experiment I. (E) Experimental strategy for Experiment II. Night-fed, night-time-fed group; Day-fed, daytime-fed group; W, weeks.
FIGURE 2
FIGURE 2
Morphological evaluation of follicles and corpora lutea of the control ovary. (A) Healthy follicles no less than 250 µm in mean diameter (red asterisks) and corpora lutea no less than 600 µm in mean diameter (black asterisks). (B) Magnified image of the corpus luteum (dotted line). Vascular network within the corpus luteum was observed (white arrows). (C) Preovulatory follicle containing an oocyte and cumulus (black arrowhead). CL, corpus luteum; GC, granulosa cells; Oc, oocyte. Bars: 200 µm.
FIGURE 3
FIGURE 3
Gain in body weight and amount of food intake during dietary restriction. (A) Daily changes in body weight of the control I, night-time-fed, and daytime-fed groups during dietary restriction. The gain in body weight of the daytime-fed group was significantly reduced compared with the control I and night-time-fed groups. **P < 0.01; *P < 0.05 (control group I compared with daytime-fed group); #P < 0.05 (control group I compared with night-time-fed group). (B) Weekly amount of food intake also decreased in the daytime-fed group. **P < 0.01; *P < 0.05.
FIGURE 4
FIGURE 4
Effects of calorie restriction in the night-time-fed rats. To evaluate the possible involvement of calorie restriction in reproductive dysfunction, a 20% reduction in daily food supply was loaded on the night-time-fed group. (A) Growing curve of body weight. Gain in body weight of the 20%-reduced night-time-fed group was significantly lower than that in the control group II. (B) Amount of food intake. In accordance with A, weekly amount of food intake in the night-time-fed group was significantly lower than that in the control group II. The mean final food intake in the night-time-fed group was 72.4% of that in the control group II. (C) Ovulation numbers shown as the median and interquartile range in the 2 groups. Despite marked reductions in calorie intake and body weight gain, there was no difference in estrus cyclicity between the 2 groups. **P < 0.01; *P < 0.05; n.s.: not significant.
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References

    1. Das JK, Salam RA, Thornburg KL, Prentice AM, Campisi S, Lassi ZS, Koletzko B, Bhutta ZA. Nutrition in adolescents: Physiology, metabolism, and nutritional needs. Ann NY Acad Sci 2017;1393:21–33. - PubMed
    1. Fujiwara T. Diet during adolescence is a trigger for subsequent development of dysmenorrhea in young women. Int J Food Sci Nutr 2007;58:437–44. - PubMed
    1. Wärnberg J, Nova E, Romeo J, Moreno LA, Sjöström M, Marcos A. Lifestyle-related determinants of inflammation in adolescence. Br J Nutr 2007;98(Suppl 1):S116–120. - PubMed
    1. Most J, Tosti V, Redman LM, Fontana L. Calorie restriction in humans: An update. Ageing Res Rev 2017;39:36–45. - PMC - PubMed
    1. Nazni P. Association of western diet and lifestyle with decreased fertility. Indian J Med Res 2014;140(Suppl):S78–81. - PMC - PubMed

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