The influence of dietary protein on the experimental epidemiology of Heligmosomoides polygyrus (Nematoda) in the laboratory mouse

1988 ◽  
Vol 234 (1275) ◽  
pp. 239-254 ◽  
Keyword(s):  
Dietary Protein ◽  
Female Worm ◽  
Laboratory Mouse ◽  
Experimental System ◽  
Intestinal Helminth ◽  
Heligmosomoides Polygyrus ◽  
Protein Cage ◽  
Low Protein ◽  
Host Mortality ◽  
Aspiculuris Tetraptera

The influence of dietary protein on the epidemiology of an intestinal helminth infection was investigated with an experimental system that allowed transmission of the nematode Heligmosomoides polygyrus to occur naturally between laboratory mice. Mortality of mice was greatly increased in infected populations that were fed ad libitum on synthetic diets containing 2 % compared with 16% protein. Larger numbers of larval and adult H. polygyrus were found to infect mice in the low-protein cage compared with the high-protein cage. No evidence for density dependence in the fecundity of female worms was detected; on average the daily egg output per female worm was greater for parasites infecting mice in the low-protein cage. The rate at which naïve mice acquired infection was also higher in the low-protein cage. Pinworm ( Aspiculuris tetraptera ) became established in each cage, and average worm burdens were again greater in the low-protein cage. The acquisition of resistance to reinfection was not found to be an important factor influencing the survival of parasites infecting mice in either cage. The epidemiology of H. polygyrus and A. tetraptera was therefore characterized by low average worm burdens and high host survival in a well-nourished population of mice, and by a high intensity of infection and severe parasite-induced host mortality in a malnourished colony of mice. This reflects differences in the survival and fecundity of adult parasites between mice in the two cages, and suggests that malnourished mice are predisposed to acquire large numbers of several species of intestinal worm.

Epidemiology of Heligmosomoides polygyrus in mice: experiments on natural transmission

Parasitology ◽  
1986 ◽  
Vol 93 (1) ◽  
pp. 177-187 ◽  
Author(s):  
A. F. G. Slater ◽  
A. E. Keymer
Keyword(s):  
Community Dynamics ◽  
Laboratory Mouse ◽  
High Protein Diet ◽  
Experimental System ◽  
Protein Diet ◽  
Acquired Immunity ◽  
Intensity Of Infection ◽  
Heligmosomoides Polygyrus ◽  
Mouse Population ◽  
Frequency Distributions

SUMMARYAn experimental system is described for the study of the community dynamics of helminth–host populations, using Heligmosomoides polygyrus in the laboratory mouse. The results of a preliminary experiment using closed populations of 50 mice revealed that coexistence of host and parasite occurs for at least 4 months in the absence of immigration, with the generation of epidemiological patterns similar to those observed in the real world. In well-nourished mice the prevalence and intensity of infection initially increased with time and then declined, probably as a result of acquired immunity. The prevalence and intensity of infection increased less rapidly among hosts fed on a low protein diet, but continued to rise over the entire duration of the experiment. This continued rise is interpreted as evidence of a negative effect of protein malnutrition on host immunocompetence. The frequency distributions of parasite numbers/host were over-dispersed in each mouse population. No density dependence in parasite fecundity was detected. Aspiculuris tetraptera was also found to be present in the mouse populations. This parasite was not transmitted between mice fed on a high protein diet, but rose to a prevalence of 80 % in protein malnourished animals. No association between the intensity of A. tetraptera and H. polygyrus could be detected in individual hosts. The results are discussed in terms of the future potential of the system for the investigation of the role of acquired immunity (and its genetic control) in the generation of epidemiological patterns.

Protein content of CBA/Ca mouse diet: relationship with host antibody responses and the population dynamics ofTrichuris muris(Nematoda) in repeated infection

Parasitology ◽  
1992 ◽  
Vol 105 (1) ◽  
pp. 139-150 ◽  
Author(s):  
E. Michael ◽  
D. A. P. Bundy
Keyword(s):  
Population Dynamics ◽  
Dietary Protein ◽  
Protein Diet ◽  
Intestinal Helminth ◽  
Acquired Immunity ◽  
Trichuris Muris ◽  
Infection Dose ◽  
Low Protein ◽  
Repeated Infection ◽  
Protein Diets

The influence of host dietary protein on acquired immunity and intestinal helminth population dynamics during repeated infection was studied using the mouse–Trichuris murisexperimental model. CBA/Ca mice fed a 2% (by mass) protein dietad libitummaintained body weight during the experiment, but when fed diets containing either 4% or 16% (by mass) protein gained weight steadily. Infection withT. murisdid not affect the growth of the latter mice but significantly reduced the growth of animals fed on the 2% protein diet. When repeatedly infected with either 5 or 50 eggs every 10 days, the mice fed the 2% or 4% protein diet accumulated adults in proportion to infection dose. The results show that this is due to both the establishment of larvae at each repeated infection and the survival of established adults. In contrast, very few worms were recovered from animals fed the 16% protein diet, principally as a result of the development of strong acquired immunity to reinfection.T. murisegg output/mouse increased with infection dose in animals fed the low protein diets, but no parasite eggs were detected in the faeces of hosts fed the 16% protein diet. Mouse antibody reponses to adult worm excretory/secretory antigen were time- and infection dose-dependent in all 3 dietary groups. The major finding was that the specific antibody response was more intense, both quantitatively (serum OD levels) and qualitatively (antigen recognition by IgG1), in mice fed the low protein diets, even though they remained susceptible to infection. This study shows that host dietary protein deficiency, even at levels irrelevant to normal growth, can markedly potentiate the transmission ofT. murisvia alterations in host resistance. The high levels of antibody in susceptible animals suggest that this defect in resistance is unlikely to be due to nutrient deficiency-associated defects in humoral immunity.

Dietary protein and zinc restrictions independently modify a Heligmosomoides polygyrus (Nematoda) infection in mice

Parasitology ◽  
1998 ◽  
Vol 116 (5) ◽  
pp. 449-462 ◽  
Author(s):  
M. BOULAY ◽  
M. E. SCOTT ◽  
S. L. CONLY ◽  
M. M. STEVENSON ◽  
K. G. KOSKI
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Dietary Protein ◽  
Body Weight Gain ◽  
Challenge Infection ◽  
Host Susceptibility ◽  
Albumin Concentration ◽  
Heligmosomoides Polygyrus ◽  
Low Protein ◽  
Marginal Zinc Deficiency

The effects of dietary protein and zinc restrictions on Heligmosomoides polygyrus were compared following primary and challenge infection in female BALB/c mice fed either control (24%), marginal (7%) or low (3%) protein combined with either high or low zinc (60 or 3 mg Zn/kg diet). Dietary protein restriction (3%) resulted in significantly lower body weight gain. As well, blood urea nitrogen (BUN) significantly decreased with decreasing dietary protein level. However, neither plasma albumin concentration nor relative thymus or spleen weights were reduced. Marginal zinc deficiency was confirmed by significantly lower tibia and liver zinc concentration, but food intake, body weight gain, relative thymus and spleen weights, and alkaline phosphatase activity were not altered. On day 29 post-primary infection, worm burdens were significantly higher in mice fed either marginal or low protein and in mice fed a low zinc diet, while parasite egg output was significantly higher in mice fed both low protein and low zinc diets. Immune status was compromised in mice fed low protein (significantly lower serum IgG1 and lower eosinophilia), and in mice fed low zinc diet (significantly lower eosinophilia). Early in the infection, IgE titres were elevated in mice fed low protein or low zinc, but IgE titres declined to levels lower than the control diet groups after 14–21 days. On day 29 post-challenge infection, worm burdens and parasite egg output were significantly higher in mice fed low protein, whereas the other groups had expelled almost all parasites. Dietary restriction had no effect on serum IgE. Significantly reduced serum IgG1 titres and eosinophilia in mice fed 3% protein supported the view that low dietary protein but not low zinc increased host susceptibility to H. polygyrus by compromising host immune function following reinfection in immunized mice.

The effect of the protein content of CBA/Ca mouse diet on the population dynamics of Trichuris muris (Nematoda) in primary infection

Parasitology ◽  
1991 ◽  
Vol 103 (3) ◽  
pp. 403-411 ◽  
Author(s):  
E. Michael ◽  
D. A. P. Bundy
Keyword(s):  
Protein Content ◽  
Dietary Protein ◽  
Primary Infection ◽  
Population Biology ◽  
Similar Rate ◽  
Protein Diet ◽  
Intestinal Helminth ◽  
Trichuris Muris ◽  
Infection Dose ◽  
Low Protein

The relationship between host dietary protein and intestinal helminth population biology during primary infection was studied using a mouse–T. muris experimental model. Uninfected CBA/Ca mice fed either a 4% (by mass) or 16% protein diet grew at a similar rate, but both suffered significant growth retardation when infected with T. muris. T. muris initial establishment and fecundity were unaffected by dietary protein content, but were significantly influenced by infection dose, declining at the higher level of infection. Dietary protein deficiency increased parasite survival at high infection levels. Heavily infected hosts fed the 16% protein diet were found to expel almost the whole of their infections around day 21 p.i. By contrast, this response appeared defective in hosts fed the lower 4% protein diet, resulting in the establishment and survival of large, chronic and patent infections. Mean faecal egg output per mouse increased with infection dose in animals fed a low protein diet, but was low and unrelated to infection exposure in hosts fed the 16% protein diet. It is concluded that low protein levels in diet, via alterations in host resistance, may have an important influence on the transmission of T. muris.

scholarly journals Severe protein deficiency induces hepatic expression and systemic level of FGF21 but inhibits its hypothalamic expression in growing rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Joanna Moro ◽  
Catherine Chaumontet ◽  
Patrick C. Even ◽  
Anne Blais ◽  
Julien Piedcoq ◽  
...  
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Energy Expenditure ◽  
Energy Intake ◽  
Dietary Protein ◽  
Protein Deficiency ◽  
Protein Diet ◽  
Growing Rats ◽  
Low Protein ◽  
Protein Diets

AbstractTo study, in young growing rats, the consequences of different levels of dietary protein deficiency on food intake, body weight, body composition, and energy balance and to assess the role of FGF21 in the adaptation to a low protein diet. Thirty-six weanling rats were fed diets containing 3%, 5%, 8%, 12%, 15% and 20% protein for three weeks. Body weight, food intake, energy expenditure and metabolic parameters were followed throughout this period. The very low-protein diets (3% and 5%) induced a large decrease in body weight gain and an increase in energy intake relative to body mass. No gain in fat mass was observed because energy expenditure increased in proportion to energy intake. As expected, Fgf21 expression in the liver and plasma FGF21 increased with low-protein diets, but Fgf21 expression in the hypothalamus decreased. Under low protein diets (3% and 5%), the increase in liver Fgf21 and the decrease of Fgf21 in the hypothalamus induced an increase in energy expenditure and the decrease in the satiety signal responsible for hyperphagia. Our results highlight that when dietary protein decreases below 8%, the liver detects the low protein diet and responds by activating synthesis and secretion of FGF21 in order to activate an endocrine signal that induces metabolic adaptation. The hypothalamus, in comparison, responds to protein deficiency when dietary protein decreases below 5%.

Effects of variations in dietary protein levels on hair growth and pelt quality in mink (Mustela vison)

2000 ◽  
Vol 80 (4) ◽  
pp. 633-642 ◽  
Author(s):  
Palle V. Rasmussen ◽  
Christian F. Børsting
Keyword(s):  
Protein Content ◽  
Dietary Protein ◽  
Protein Level ◽  
Hair Growth ◽  
Fibre Length ◽  
Hair Follicles ◽  
Protein Levels ◽  
Low Protein ◽  
Pregnancy And Lactation ◽  
Hair Fibre

The effect of different and shifting dietary protein levels on hair growth and the resulting pelt quality in mink was studied. Two groups of pastel female mink were fed either 59% (high protein, HP) or 40% (low protein, LP) of metabolisable energy (ME) from protein during pregnancy and lactation. Shortly after weaning, kits from females fed the LP diet were put on a new LP diet (21% protein of ME). Kits from females fed HP were randomly distributed to four experimental groups fed a new HP diet (34% protein of ME) and three of these groups were shifted to diets with 21% protein at different times during June until September. Skin biopsies were taken at 4, 6, 23 and, 29 wk of age. Histological techniques and computer-assisted light microscopy were used to determine the ratio of activity (ROA) of underfur and guard hairs, respectively, defined as the number of growing hairs as a percentage of the total number of hairs. The hair fibre length and thickness were determined by morphometric methods and correlated with fur properties of dried pelts judged by sensory methods. It was documented that 40% of ME from protein during pregnancy and lactation was sufficient for mink kits to express their genetic capacity to produce hair follicles. In males, a reduced protein level from the age of 15 wk or 22 wk until pelting disturbed moulting, indicated by a low ROA of underfur hairs at 23 wk, and consequently reduced the growth and development of the winter coat. A constantly low protein level from conception until the age of 29 wk did not disturb moulting, but led to a reduction of primeness and especially of the underfur length and fibre thickness of the winter coat. A low protein level from the age of 9 wk only reduced the thickness of the underfur fibres. Hair growth, final fur volume, and general quality of the winter coat of males were influenced negatively and to the same degree in all groups fed the LP diet in part of the growth period. The number of underfur hairs per area (hair density) of the winter coat was not influenced by the dietary treatment meaning that the protein content of 21% of ME in the LP diet was high enough for the mink to express its genetic capacity to develop hair follicles. However, this low protein content led to a reduction of hair fibre length and hair fibre thickness of the underfur. Overall, this study demonstrated that hair growth and hair properties in pelts are very dependent on the dietary protein supply in the period from 22 wk of age until pelting, irrespective of the supply in the preceding periods. Key words: Fur properties, hair fibres, nutrition, pelage, protein requirement

EFFECTS OF GRADED DIETARY PROTEIN LEVELS ON UREA RECYCLING IN THE PIG

1982 ◽  
Vol 62 (4) ◽  
pp. 1193-1197 ◽  
Author(s):  
P. A. THACKER ◽  
J. P. BOWLAND ◽  
L. P. MILLIGAN ◽  
E. WELTZIEN
Keyword(s):  
Dietary Protein ◽  
Protein Diet ◽  
Nitrogen Excretion ◽  
Entry Rate ◽  
Protein Nitrogen ◽  
Protein Levels ◽  
Low Protein ◽  
Key Words Pig ◽  
Urea Recycling ◽  
Protein Diets

The kinetics of urea recycling were determined in six female crossbred pigs utilizing a radioisotope dilution technique. The experimental animals were fed three times daily 500 g of a corn-soybean meal diet formulated to contain 8.4, 15.8 or 24.7% crude protein. Nitrogen digestibility, urinary nitrogen excretion, total nitrogen excretion and retained nitrogen were highest on the 24.7% protein diet and decreased with decreasing dietary protein. Urea pool size, entry rate and excretion rate were also highest on the 24.7% protein diet and decreased with decreasing protein intake. Expressed as a percentage of the total entry rate, a significantly higher percentage of urea was recycled in pigs fed the low protein diets compared with those fed a higher protein diet. Key words: Pig, urea, recycling, kinetics, protein

scholarly journals Restriction of dietary protein leads to conditioned protein preference and elevated palatability of protein-containing food in rats

2017 ◽  
Author(s):  
Michelle Murphy ◽  
Kate Z. Peters ◽  
Bethany S. Denton ◽  
Kathryn A. Lee ◽  
Heramb Chadchankar ◽  
...  
Keyword(s):  
Dietary Protein ◽  
Food Choice ◽  
Cluster Size ◽  
Preference Test ◽  
Protein Restriction ◽  
Restricted Diet ◽  
Adult Rats ◽  
Low Protein ◽  
Casein Protein ◽  
Over Time

AbstractThe mechanisms by which intake of dietary protein is regulated are poorly understood despite their potential involvement in determining food choice and appetite. In particular, it is unclear whether protein deficiency results in a specific appetite for protein and whether influences on diet are immediate or develop over time. To determine the effects of protein restriction on consumption, preference, and palatability for protein we assessed patterns of intake for casein (protein) and maltodextrin (carbohydrate) solutions in adult rats. To induce a state of protein restriction, rats were maintained on a low protein diet (5% casein) and compared to control rats on non-restricted diet (20% casein). Under these dietary conditions, relative to control rats, protein-restricted rats exhibited hyperphagia without weight gain. After two weeks, on alternate conditioning days, rats were given access to either isocaloric casein or maltodextrin solutions that were saccharin-sweetened and distinctly flavoured whilst consumption and licking patterns were recorded. This allowed rats to learn about the post-ingestive nutritional consequences of the two different solutions. Subsequently, during a preference test when rats had access to both solutions, we found that protein-restricted rats exhibited a preference for casein over carbohydrate whereas non-restricted rats did not. Analysis of lick microstructure revealed that this preference was associated with an increase in cluster size and number, reflective of an increase in palatability. In conclusion, protein-restriction induced a conditioned preference for protein, relative to carbohydrate, and this was associated with increased palatability.

scholarly journals Insulin-like growth factor-I, but not growth hormone, is dependent on a high protein intake to increase nitrogen balance in the rat

1999 ◽  
Vol 81 (2) ◽  
pp. 145-152 ◽  
Author(s):  
Myriam Sanchez-Gomez ◽  
Kjell Malmlöf ◽  
Wilson Mejia ◽  
Antonio Bermudez ◽  
Maria Teresa Ochoa ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Dietary Protein ◽  
Protein Diet ◽  
N Balance ◽  
Low Protein Diet ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Low Protein ◽  
Igf I

The aim of the present study was to investigate the influence of dietary protein level on the protein anabolic effects of growth hormone (GH) and insulin-like growth factor-I (IGF-I). Female growing rats were fed on either a high- or a low-protein diet with crude protein contents of 222 and 83 g/kg respectively. The diets contained the same amount of metabolizable energy (15·1 MJ/kg) and were given during a 14 d period. During the same time, three groups of rats (n 8) on each diet received subcutaneous infusions of either saline, recombinant human GH (rhGH) or recombinant human IGF-I (rhIGF-I). rhGH and rhIGF-I were given in doses of 360 and 500 μg/d respectively. The low-protein diet alone reduced significantly (P < 0·05) IGF-I concentrations in serum and in tissue taken from the gastrocnemius muscle as well as IGF-I mRNA from the same muscle. The responses to rhGH and rhIGF-I in terms of muscle IGF-I and its mRNA were variable. However, when rhIGF-I was infused into rats on the high-protein diet, significantly elevated levels of IGF-I in muscle tissues could be observed. This was associated with a significantly (P < 0·05) increased N balance, whereas rhGH significantly (P < 0·05) enhanced the N balance in rats on the low-protein diet. Thus, it can be concluded that the level of dietary protein ingested regulates not only the effect of IGF-I on whole-body N economy but also the regulation of IGF-I gene expression in muscles. The exact mechanism by which GH exerts its protein anabolic effect, however, remains to be elucidated.

HYPERAMMONEMIA DUE TO A DEFECT IN HEPATIC ORNITHINE TRANSCARBAMYLASE

PEDIATRICS ◽  
1972 ◽  
Vol 50 (1) ◽  
pp. 100-111
Author(s):  
Philip Sunshine ◽  
Jeffrey E. Lindenbaum ◽  
Harvey L. Levy ◽  
John M. Freeman
Keyword(s):  
Citric Acid ◽  
Dietary Protein ◽  
Clinical Condition ◽  
Growth And Development ◽  
Hepatic Dysfunction ◽  
Hepatic Function ◽  
Ornithine Transcarbamylase ◽  
Red Cell ◽  
Low Protein ◽  
Orotic Aciduria

A 9-year-old girl with vomiting, changes in behavior, coma, and evidence of hepatic dysfunction at 3½ years of age was found to have hyperammonemia and decreased activity of liver ornithine transcarbamylase. When her dietary protein was reduced, she had improvement in her clinical condition and a return to normal of all hepatic function indices. Despite a defect in an enzyme of ornithine metabolism, she did not have hyperaminoacidemia, specifically hyperornithinemia, even when she had hyperammonemia. When she ingested a large amount of ornithine (300 mg/kg) she developed hyperornithinemia and hyperornithinuria. She also had orotic aciduria despite having normal activities of red cell orotidylic decarboxylase and pyrophosphorylase. Treatment with a low protein diet and citric acid supplements has been successful in preventing hyperammonemia and promoting growth and development.

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