Starvation induced anoestrus: effect of chronic food restriction on body weight, its influence on oestrous cycle and gonadotrophin secretion in rats

1983 ◽  
Vol 104 (4) ◽  
pp. 402-409 ◽  
Author(s):  
U. A. Knuth ◽  
H. G. Friesen
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Food Restriction ◽  
Oestrous Cycle ◽  
The Third ◽  
Serum Lh ◽  
Gonadotrophin Secretion ◽  
Normal Chow ◽  
Chronic Food Restriction ◽  
Intact Rats

Abstract. To test the effect of chronic starvartion on gonadotrophin secretion and oestrous cycles, rats were fed 50% of their normal chow consumption for 16 days. This caused an increasing rate of anoestrus which became significant during the third expected cycle (6 of 10 rats, P < 0.02) and increased to 8 of 10 rats (P < 0.0001) between day 12 and 16. The accompanying weight loss was around 13 and 17%, respectively. Pituitary weights in intact rats killed on dioestrus became significantly different after 8 days of chow reduction (12.8 ± 0.2 vs 11.3 ±0.4 mg, P < 0.02) with further reductions in groups killed after 12 and 16 days. At this time dioestrous serum FSH levels were significantly inceased in starved rats (112 ± 16 vs 161 ± 13 ng/ml, P < 0.01), while serum LH levels decreased significantly after 12 days (25.0 ± 3.4 vs 13.1 ± 8.8 ng/ml, P < 0.001). Starvation decreased the LH response to LRH administration compared to pro-oestrous controls (1934 ± 672 vs 289 ± 39 ng/ml, P < 0.05), whereas the FSH response was not impaired (457 ± 91 vs 336 ± 54 ng/ml, P > 0.05). In contrast to this pituitary content of LH was similar in both groups, while FSH content was significantly higher in starved animals (13.6 ± 1.7 vs 19.8 ± 1.2 μg, P < 0.01). Chronic starvation immediately after ovariectomy did not affect the post-castrational rise of gonadotrophins. However, LRH administration caused higher serum FSH levels in starved rats (1540 ± 91 vs 1833 ± 90 ng/ml, P < 0.05), whereas LH values did not differ (908 ± 192 vs 721 ± 153 ng/ml, P> 0.05). Gonadotrophin content per pituitary in castrated rats after 16 days of starvation was unchanged.

Physical activity: benefit or weakness in metabolic adaptations in a mouse model of chronic food restriction?

2015 ◽  
Vol 308 (3) ◽  
pp. E241-E255 ◽  
Author(s):  
Mathieu Méquinion ◽  
Emilie Caron ◽  
Sara Zgheib ◽  
Aliçia Stievenard ◽  
Philippe Zizzari ◽  
...  
Keyword(s):  
Physical Activity ◽  
Body Weight ◽  
Protective Effect ◽  
Food Restriction ◽  
Plasma Concentrations ◽  
Body Weight Loss ◽  
Severe Condition ◽  
The Impact ◽  
Chronic Food Restriction

In restrictive-type anorexia nervosa (AN) patients, physical activity is usually associated with food restriction, but its physiological consequences remain poorly characterized. In female mice, we evaluated the impact of voluntary physical activity with/without chronic food restriction on metabolic and endocrine parameters that might contribute to AN. In this protocol, FRW mice (i.e., food restriction with running wheel) reached a crucial point of body weight loss (especially fat mass) faster than FR mice (i.e., food restriction only). However, in contrast to FR mice, their body weight stabilized, demonstrating a protective effect of a moderate, regular physical activity. Exercise delayed meal initiation and duration. FRW mice displayed food anticipatory activity compared with FR mice, which was strongly diminished with the prolongation of the protocol. The long-term nature of the protocol enabled assessment of bone parameters similar to those observed in AN patients. Both restricted groups adapted their energy metabolism differentially in the short and long term, with less fat oxidation in FRW mice and a preferential use of glucose to compensate for the chronic energy imbalance. Finally, like restrictive AN patients, FRW mice exhibited low leptin levels, high plasma concentrations of corticosterone and ghrelin, and a disruption of the estrous cycle. In conclusion, our model suggests that physical activity has beneficial effects on the adaptation to the severe condition of food restriction despite the absence of any protective effect on lean and bone mass.

Acute food deprivation and chronic food restriction differentially affect hypothalamic NPY mRNA expression

2003 ◽  
Vol 285 (5) ◽  
pp. R1030-R1036 ◽  
Author(s):  
Sheng Bi ◽  
Benjamin M. Robinson ◽  
Timothy H. Moran
Keyword(s):  
Gene Expression ◽  
Body Weight ◽  
Food Deprivation ◽  
Food Restriction ◽  
Leptin Receptor ◽  
Receptor Gene ◽  
Body Weight Loss ◽  
Receptor Expression ◽  
Mrna Levels ◽  
Chronic Food Restriction

Although acute food deprivation and chronic food restriction both result in body weight loss, they produce different metabolic states. To evaluate how these two treatments affect hypothalamic peptide systems involved in energy homeostasis, we compared patterns of hypothalamic neuropeptide Y (NPY), agouti-related protein (AgRP), proopiomelanocotin (POMC), and leptin receptor gene expression in acutely food-deprived and chronically food-restricted rats. Both acute food deprivation and chronic food restriction reduced body weight and circulating leptin levels and resulted in increased arcuate NPY and decreased arcuate POMC gene expression. Arcuate AgRP mRNA levels were only elevated in acutely deprived rats. NPY gene expression was increased in the compact subregion of the dorsomedial hypothalamus (DMH) in response to chronic food restriction, but not in response to acute food deprivation. Leptin receptor expression was not affected by either treatment. Double in situ hybridization histochemistry revealed that, in contrast to the situation in the arcuate nucleus, NPY and leptin receptor mRNA-expressing neurons were not colocalized in the DMH. Together, these data suggest that arcuate and DMH NPY gene expression are differentially regulated. DMH NPY-expressing neurons do not appear to be under the direct control of leptin signaling.

Possible site of negative and positive feedback action of oestrogen on gonadotrophin secretion in normal women

1985 ◽  
Vol 108 (4) ◽  
pp. 440-444 ◽  
Author(s):  
Yasuhito Nagahara ◽  
Akira Miyake ◽  
Keiichi Tasaka ◽  
Yasuhiro Kawamura ◽  
Toshihiro Aono ◽  
...  
Keyword(s):  
Positive Feedback ◽  
Direct Action ◽  
Feedback Effects ◽  
The Third ◽  
Serum Lh ◽  
Gonadotrophin Secretion ◽  
Site Of Action ◽  
The Mean ◽  
Normal Women

Abstract. For determination of the site of action of oestrogen (E) during the negative and positive feedback phases of gonadotrophin secretions, studies were made on the pituitary response to a small amount of LRH and the pulsatility of gonadotrophins after E administration in normal cycling women in the mid-follicular phase. The pituitary responses to an iv bolus of 2.5 μg of synthetic LRH were evaluated by measuring serum LH and FSH 2 h before and 8 h after administration of 20 mg of conjugated E (Premarin). In the next cycle, the pituitary responses to a same dose of LRH were also observed 2 h before and 56 h after E injection. The mean levels of serum LH and FSH and the peak responses to LRH were significantly (P < 0.05) decreased 8 h after E injection, but were significantly (P < 0.05) increased 56 h after E administration. In the third cycle, the pulsatility of gonadotrophins was evaluated by measuring serum LH and FSH every 15 min for 180 min before and 8 h and 56 h after E injection. The pulse frequencies of gonadotrophins were not significantly different before and 8 h and 56 h after E injection. The amplitudes of pulses 56 h after Premarin injection were significantly higher than those before the injection. These findings suggest that the negative and positive feedback effects of E on gonadotrophin secretion may be caused, in part, by its direct action on the pituitary response to LRH.

Decrease of LRH receptors in the pituitary gland in streptozotocin-induced diabetic rats

1985 ◽  
Vol 110 (1) ◽  
pp. 46-49 ◽  
Author(s):  
Keiichi Tasaka ◽  
Naoki Terakawa ◽  
Ikuya Shimizu ◽  
Shirou Ohtsuka ◽  
Akira Miyake ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Body Weight ◽  
Serum Concentration ◽  
Pituitary Gland ◽  
Diabetic Rats ◽  
Oestrous Cycle ◽  
Female Rats ◽  
Normal Female ◽  
Medial Basal Hypothalamus ◽  
Serum Lh

Abstract. In studies into the mechanism of anovulation in the diabetic condition, the LRH receptor content of the pituitary gland of rats with diabetes mellitus was determined. Normal female rats weighing 180–200 g were injected iv with either streptozotocin (6 mg/100 g body weight) or vehicle in dioestrus of the oestrous cycle. The rats were sacrificed by decapitation 9 days after treatment, and serum LH concentrations and the LRH content of the medial basal hypothalamus (MBH) were measured by radioimmunoassay (RIA), and the LRH receptor content of the pituitary gland was determined. The serum concentration of LH and the LRH content of the MBH in diabetic rats were 34.4 ± 4.8 ng/ml (mean ± sem) and 2.05 ± 0.04 ng/MBH, respectively, which were similar to the respective values of normal rats in dioestrus. However, the LRH receptor content of diabetic rats (13.2 ± 3.9 fmol/pituitary) was significantly (P < 0.05) lower than that of normal rats in dioestrus (68.0 ± 7.1 fmol/pituitary) and pro-oestrus (59.4 ± 13.6 fmol/pituitary). These results suggest that anovulation in diabetic rats is at least partly attributable to a low content of LRH receptors in the pituitary gland.

Effect of meal pattern during food restriction on body weight loss and recovery after refeeding

1993 ◽  
Vol 53 (3) ◽  
pp. 421-424 ◽  
Author(s):  
Brenda S Brownlow ◽  
Collin R Park ◽  
Robert S Schwartz ◽  
Stephen C Woods
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Food Restriction ◽  
Body Weight Loss ◽  
Meal Pattern

Factors Influencing Survival of Rats in Fasting

1957 ◽  
Vol 188 (2) ◽  
pp. 332-336 ◽  
Author(s):  
R. H. Rixon ◽  
J. A. F. Stevenson
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Metabolic Rate ◽  
Environmental Temperature ◽  
Body Weight Loss ◽  
Initial Body Weight ◽  
Adult Rats ◽  
Factors Influencing ◽  
The Individual ◽  
Intact Rats

The individual duration of survival of adult rats in complete fasting varied considerably; the range at an environmental temperature of 22°C was 6–16 days, at 2–5°C, 1–7 days, and in thyroidectomized animals at 22°C, 15–25 days. This variation in survival was not closely related to the initial body weight but was related to the individual proportionate body weight loss per day and the total proportionate weight loss sustained before death. The individual proportionate rate of weight loss has been correlated with the metabolic rate indicating that the former reflected the metabolic rate of the animal. The duration of survival in fasting has been correlated with the individual metabolic rate, whether measured before or during fasting. Since fasting did not obliterate or reduce the individual differences in metabolic rate, it was possible to predict the individual duration of survival from knowledge of the prefasting metabolic rate. The total proportionate weight loss, which also influenced the survival time in fasting, was altered by changes in the environmental temperature and probably by other factors. The previous diet whether high in protein, fat or carbohydrate had little effect on the duration of survival. Fasting caused a decrease in the metabolic rate of intact rats at 22°C but no change in that of thyroidectomized rats or of rats living in the cold.

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