Low-Protein Diet Changes Thyroid Function in Lactating Rats

Ramos, Cristiane F.; Teixeira, Cíntia Vilanova; Passos, M. C. F.; Pazos‐Moura, Carmen C.; Lisboa, Patrícia Cristina; Curty, F. H.; Moura, Egberto Gaspar de

doi:10.1046/j.1525-1373.2000.22429.x

Cited by 46 publications

(32 citation statements)

References 41 publications

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“…The same alteration was also described in animals that received a cafeteria diet (14,16) or protein-and energy-restricted diets (12,28,29). Furthermore, since the high-fat diet is instituted abruptly during the third week of gestation, the novelty of the diet could create a food avoidance behavior that could explain the early reduction of food ingestion.…”

Section: Discussionmentioning

confidence: 53%

“…We have shown that protein-restricted diets lead to a decrease in 131 I thyroid uptake and to higher serum TSH and lower T 4 concentrations, but surprisingly the animals in that study (12) had higher serum T 3 concentrations due in part to a higher thyroid T 4 to T 3 conversion (33). In contrast, energy-restricted mothers had no change in thyroid radioiodine uptake and lower serum TSH, T 4 and T 3 concentrations.…”

Section: Control Diet Groupmentioning

confidence: 60%

“…Some investigators have shown that the nutritional status of the mother during the gestational and lactational periods is essential to normal growth and development in humans (6)(7)(8) and in experimental animals (9)(10)(11)(12)(13)(14)(15).…”

Section: Introductionmentioning

confidence: 99%

“…We have recently shown that proteinrestricted lactating dams present a loss of body weight gain (12), alterations in milk composition (11) and an important adaptive change in thyroid function by increasing the transfer of iodine and T 3 through the milk to their pups, probably preventing an eventual neonatal hypothyroidism (9,10,12).…”

Section: Introductionmentioning

confidence: 99%

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Adaptive changes in thyroid function of female rats fed a high-fat and low-protein diet during gestation and lactation

Brito

Ramos

Passos

et al. 2006

Braz J Med Biol Res

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The percent of lipids in the western diet has been continuously increasing in the last decades and is associated with a decrease in the proportion of protein intake. Recently, we demonstrated that protein malnutrition during lactation is associated with lower body weight and thyroid hypofunction in female rats and their offspring. Our objective in the present study was to determine if a high-fat and lowprotein diet was associated with similar changes. Three-month-old female Wistar rats were randomly assigned to one of the following groups with 8 animals each: high-fat and low-protein (40% lipid, 5% protein, and 55% carbohydrate of the total energy content) from the 3rd week of gestation to the end of lactation; control group -standard diet (11% lipid, 23% protein, and 66% carbohydrate of the total energy content). Food consumption and body weight were monitored daily. Serum thyrotropin and thyroid hormone concentrations were determined by specific radioimmunoassay at the end of lactation. Animals receiving high-fat and low-protein diet had a significantly lower body weight (13.9% at weaning, P < 0.05) and serum albumin (25%, P < 0.05) and thyrotropin (26.2%, P < 0.01) concentrations, and a higher serum triiodothyronine concentration (74%, P < 0.005) and 131 I-thyroid uptake (77%, P < 0.005). These data show that a high-fat and low-protein diet can promote maternal thyroid hyperfunction that differs from the thyroid hypofunction observed in dams fed a lowprotein diet, a phenomenon that can be of adaptive importance for pup nurturing.

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Section: Discussionmentioning

confidence: 53%

Section: Control Diet Groupmentioning

confidence: 60%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Adaptive changes in thyroid function of female rats fed a high-fat and low-protein diet during gestation and lactation

Brito

Ramos

Passos

et al. 2006

Braz J Med Biol Res

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“…Our previous studies showed short-and long-term effects of malnutrition during lactation on the thyroid function of mothers and their offspring (Ramos et al 2000, Passos et al 2001a,b, 2002. Dams submitted to a proteinrestricted (PR) diet during lactation had, at weaning, a significant decrease in 131 I thyroid uptake and an increase in 131 I uptake by the mammary gland and a higher transfer of 131 I to the milk when compared with controls (Ramos et al 2000). These animals had higher tri-iodothyronine (T 3 ) levels in serum and milk, and lower serum levels of thyroxine (T 4 ) during lactation (Passos et al 2001a).…”

Section: Introductionmentioning

confidence: 99%

Increased 5'-iodothyronine deiodinase activity is a maternal adaptive mechanism in response to protein restriction during lactation

Lisboa¹,

Passos²,

Dutra³

et al. 2003

Journal of Endocrinology

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We have shown that protein restriction during lactation is associated with higher levels of serum and milk tri-iodothyronine (T 3 ) with lower serum thyroxine (T 4 ), suggesting an increased T 4 to T 3 conversion. To investigate this hypothesis, the activity of type 1 (D1) and/or type 2 (D2) iodothyronine deiodinases was evaluated on days 4, 12 and 21 of lactation in several tissues of dams fed an 8% protein-restricted (PR) diet and controls fed a 23% protein diet. Serum TSH, T 3 and T 4 were measured by radioimmunoassay. Deiodinase activity was determined by the release of 125 I from 125 I-reverse T 3 , under specific conditions for D1 or D2. PR dams had a transitory reduction in liver D1 activity (P<0·05) on day 12, and a small increase in thyroid D1 on day 12 followed by a small decrease on day 21. However, thyroid D2 activity was higher than controls (P<0·05) during the whole of the lactation period. Mammary gland D1 and D2 activities were lower on day 4 of lactation in PR dams (P<0·05), and D2 was higher on day 21 (P<0·05). Potentially, a lower conversion of T 3 to di-iodothyronine in the mammary glands of PR dams at the beginning of lactation may serve to provide more T 3 through the milk. Brown adipose tissue (BAT) D2 activity was higher (P<0·05) in PR dams during all periods of lactation. PR dams showed higher skeletal muscle D1 activity only at the end of lactation, but no changes in D2 activity. Higher pituitary D1 and D2 activities in the PR group (P<0·05) at the end of lactation could have contributed to the lower serum TSH. These data suggest that the higher thyroid and BAT D2 activity during the whole of lactation and skeletal muscle D1 activity at the end of lactation may contribute to the higher serum T 3 in PR dams.

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Influence of dietary protein on serum metabolites and antioxidant status: A study in Chrysolophus amherstiae

et al. 2016

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This experiment was conducted to study the effect of feeding graded levels of dietary crude protein (CP) on serum biochemical profile of Lady Amherst's pheasants (LAP). Eighteen male LAP were randomly distributed into three groups of six each in an experiment based on completely randomized design. The CP content of the diets was 13.4%, 16.5%, and 19.1%, in groups I, II, and III, respectively. Serum concentrations of uric acid was lowest (P < 0.05) in group I. Relationship between serum concentration of uric acid and nitrogen intake was linear (R(2) = 0.39, P < 0.01). Concentrations of other serum metabolites and enzymes were similar among the groups. Serum concentration of triiodothyronine (T3 ) was highest (P < 0.05) in group I, followed by groups II and III. Total antioxidant capacity (TAC) of serum was lower (P < 0.007), whereas serum concentration of malondialdehyde (MDA) was higher (P < 0.001) in group I as compared to groups II and III. Regression of serum concentration of TAC (R(2) = 0.74, P < 0.01) and MDA (R(2) = 0.39, P < 0.05) was polynomial. Heterophil to lymphocyte ratio was higher (P < 0.007) in group I as compared to groups II and III. Relationship between H/L ratio and nitrogen intake was polynomial (R(2) = 0.69, P < 0.05). Cell mediated immune response measured as foot web index was similar among the groups. Based upon the results, it was concluded that a diet containing 16.5% crude protein would be optimum for improving antioxidant defense and the ability of Lady Amherst's pheasant to combat stress. Zoo Biol. 35:346-354, 2016. © 2016 Wiley Periodicals, Inc.

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Low-Protein Diet Changes Thyroid Function in Lactating Rats

Cited by 46 publications

References 41 publications

Adaptive changes in thyroid function of female rats fed a high-fat and low-protein diet during gestation and lactation

Adaptive changes in thyroid function of female rats fed a high-fat and low-protein diet during gestation and lactation

Increased 5'-iodothyronine deiodinase activity is a maternal adaptive mechanism in response to protein restriction during lactation

Influence of dietary protein on serum metabolites and antioxidant status: A study in Chrysolophus amherstiae

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