Physiological responses of rats to primary infection with Nippostrongylus brasiliensis

1986 ◽  
Vol 60 (4) ◽  
pp. 307-312 ◽  
Author(s):  
K. S. Ovington

ABSTRACTThe physiological responses of well-nourished rats to primary infection with the intestinal nematode Nippostrongylus brasiliensis were examined. Infected rats fed ad libitum were compared with uninfected control rats fed ad lib. and also with uninfected rats which were pair-fed to the infected rats. Following infection with N. brasiliensis rat food intake was reduced from day 2 post infection (pi) and there were two periods of minimal food intake (day 2 to 3 and 8 to 9 pi). The water intake of infected rats was only reduced on days 2, 3 and 9 pi and not to the same extent as food intake. Muscle catabolism in infected rats was more severe than could be explained on the basis of their food intake reduction. The rectal temperature and rate of oxygen consumption per g body-weight of rats was not significantly altered by the infection. Host responses to N. brasiliensis are compared with those seen in microbial infections and some of them are found to be considerably different.

Parasitology ◽  
1981 ◽  
Vol 82 (1) ◽  
pp. 23-38 ◽  
Author(s):  
D. W. T. Crompton ◽  
D. E. Walters ◽  
Susan Arnold

SUMMARYThe daily food intake and related changes in body weight were measured in young rats which were fed on synthetic diets containing 1% (3 experiments), 2% (4 experiments) and 20% (1 experiment) casein respectively. Some rats were infected with Nippostrongylus brasiliensis and allowed to feed ad libitum, some remained uninfected and were allowed to feed ad libitum while others, which were matched by initial weight with rats from the infected group, remained uninfected and were given only the same amount of food as that consumed during the previous 24 h by their infected partners. No significant differences were detected between the rats before the start of the infection. Thereafter, the food intake of the infected undernourished rats was usually found to be significantly lower and the loss of body weight significantly greater than those of the uninfected rats. In infection periods of relatively long duration, the pair-fed uninfected rats did not lose as much weight as their infected partners even though their food intake (1% and 2% casein) was the same. Although the food intake, and consequently the weight, of infected rats fed on the diet containing 20% casein were significantly less than in their uninfected partners, no significant differences were observed between the weights of the infected and pair-fed rats fed on this diet.


2005 ◽  
Vol 93 (4) ◽  
pp. 493-499 ◽  
Author(s):  
Jos G. M. Houdijk ◽  
Neil S. Jessop ◽  
David P. Knox ◽  
Ilias Kyriazakis

Lactating mammals usually exhibit a breakdown of immunity to parasites, i.e. they have larger worm burdens than their non-lactating counterparts. Here, we tested the hypothesis that a secondary infection withNippostrongylus brasiliensisin lactating rats is sensitive to dietary protein content. We also tested whether this infection affects host food intake. Rats either remained uninfected throughout the study or were given a single infection before mating (primary infection) and re-infected on day 2 of lactation (secondary infection) with 1600 infective larvae. Infected rats were fed foods during lactation formulated to supply 100 (low protein; LP), 200 (medium protein; MP) or 300 (high protein; HP) g crude protein per kg DM; non-infected rats were fed either the LP or HP food. Litter size was standardized to ten pups between parturition (day 0) and secondary infection (day 2). Ten days after secondary infection, MP and HP rats had excreted fewer nematode eggs, and had fewer adult nematodes in their small intestine and nematode eggs in their colon than the LP rats. Primary infection increased food intake in late pregnancy, and increased maternal body weight and litter size at parturition. Secondary infection did not affect mean food intake, maternal and litter weight, although food intake was reduced for 1 d following infection. These results support the view that a secondary infection withN. brasiliensisis sensitive to dietary protein content, and that the latter infection does not impair lactational performance. Future studies may focus on elucidating the nutritional sensitivity of immune responses underlying the reduced secondaryN. brasiliensisinfection.


Parasitology ◽  
1985 ◽  
Vol 91 (1) ◽  
pp. 157-167 ◽  
Author(s):  
K. S. Ovington

The pattern of daily food intake of well-nourished rats infected with Nippostrongylus brasiliensis included 2 distinct phases when food intake was much less than that of uninfected controls (days 0–4 and days 6–10 p.1.). These phases were separated by a period (days 4–6) of still reduced but relatively constant food intake. From day 10 p.i. food intake increased so that between days 12 and 17 infected rats ate more than uninfected controls. In each of the phases of reduced food intake there was a threshold dose above which food intake was further decreased as dose increased. In contrast to the obvious relationship between food intake and dose, food intake could not easily be related to the size of the adult Nipposirongylus population, as judged by egg and worm counts. The relationship appears to be complicated by host variability in susceptibility to infection and to the pathological effects of infection. Effects of N. brasiliensis on the daily pattern of food intake can be explained with respect to stages in the development of the parasite and host responses directed against the adult worms.


2002 ◽  
Vol 64 (5) ◽  
pp. 423-426 ◽  
Author(s):  
Hendra WIBAWA ◽  
Deni NOVIANA ◽  
Kimiyuki TSUCHIYA ◽  
Fadjar SATRIJA ◽  
Yoichiro HORII

1966 ◽  
Vol 44 (5) ◽  
pp. 903-910 ◽  
Author(s):  
N. Mrosovsky

Cycles of food intake and body weight lasting a few weeks occurred in dormice, Glis glis, kept in the laboratory in relatively constant conditions of temperature (about 25 °C) and photoperiod (about 12 hours light–dark schedule). These fluctuations appeared to be more marked in the winter months. Periods of reduced eating were associated with low body temperatures and lethargy. The frequent disturbance and arousal of the animals was probably an important factor in these short hibernating cycles. The influence of variation of the diet on body weight of dormice is described. Animals kept on ad libitum supplies of sunflower seed became obese and remained so for many months.


Endocrinology ◽  
2002 ◽  
Vol 143 (12) ◽  
pp. 4513-4519 ◽  
Author(s):  
Csaba Fekete ◽  
Sumit Sarkar ◽  
William M. Rand ◽  
John W. Harney ◽  
Charles H. Emerson ◽  
...  

Abstract Neuropeptide Y (NPY) is one of the most important hypothalamic-derived neuropeptides mediating the effects of leptin on energy homeostasis. Central administration of NPY not only markedly stimulates food intake, but simultaneously inhibits the hypothalamic-pituitary-thyroid axis (HPT axis), replicating the central hypothyroid state associated with fasting. To identify the specific NPY receptor subtypes involved in the action of NPY on the HPT axis, we studied the effects of the highly selective Y1 ([Phe7,Pro34]pNPY) and Y5 ([chicken pancreatic polypeptide1–7, NPY19–23, Ala31, Aib32 (aminoisobutyric acid), Q34]human pancreatic polypeptide) receptor agonists on circulating thyroid hormone levels and proTRH mRNA in hypophysiotropic neurons of the hypothalamic paraventricular nucleus. The peptides were administered continuously by osmotic minipump into the cerebrospinal fluid (CSF) over 3 d in ad libitum-fed animals and animals pair-fed to artificial CSF (aCSF)-infused controls. Both Y1 and Y5 receptor agonists nearly doubled food intake compared with that of control animals receiving aCSF, similar to the effect observed for NPY. NPY, Y1, and Y5 receptor agonist administration suppressed circulating levels of thyroid hormones (T3 and T4) and resulted in inappropriately normal or low TSH levels. These alterations were also associated with significant suppression of proTRH mRNA in the paraventricular nucleus, particularly in the Y1 receptor agonist-infused group [aCSF, NPY, Y1, and Y5 (density units ± sem), 97.2 ± 8.6, 39.6 ± 8.4, 19.9 ± 1.9, and 44.6 ± 8.4]. No significant differences in thyroid hormone levels, TSH, or proTRH mRNA were observed between the agonist-infused FSanimals eating ad libitum and the agonist-infused animals pair-fed with vehicle-treated controls. These data confirm the importance of both Y1 and Y5 receptors in the NPY-mediated increase in food consumption and demonstrate that both Y1 and Y5 receptors can mediate the inhibitory effects of NPY on the HPT axis.


2007 ◽  
Vol 97 (1) ◽  
pp. 104-110 ◽  
Author(s):  
Heidi Normanton ◽  
Jos G. M. Houdijk ◽  
Neil S. Jessop ◽  
Dave P. Knox ◽  
Ilias Kyriazakis

Lactating rats experience a breakdown of immunity to parasites, i.e. they carry larger worm burdens after re-infection compared to their non-lactating counterparts. Feeding high-protein foods to lactating rats results in reduced worm burdens. This could be attributed to changes in gastrointestinal environment or to overcoming effects of nutrient scarcity on host immunity. The latter hypothesis was addressed through a manipulation of nutrient demand by manipulating litter size. Twenty-three rats were immunized prior to mating and re-infected on day 2 of lactation with 1600 infective Nippostrongylus brasiliensis larvae. From parturition onwards, rats received ad libitum a low-protein food (100 g crude protein/kg). Litter sizes were standardised to nine (LS9), six (LS6) or three (LS3) pups, by day 2 of lactation. After a further 10 d, LS9 and LS6 rats carried more worms than LS3 rats. However, feeding treatments did not affect concentrations of mucosal inflammatory cells. Achieved feed intake did not differ consistently between the treatment groups. However, LS9 and LS6 rats lost weight, whilst LS3 rats gained weight during lactation. The results support the view that resistance to N. brasiliensis is sensitive to changes in nutrient demand, and the improved resistance to N. brasiliensis is likely due to effects of overcoming nutrient scarcity on host immunity.


1985 ◽  
Vol 36 (3) ◽  
pp. 483 ◽  
Author(s):  
JK Egan ◽  
PT Doyle

Six mature Merino sheep received three treatments in a randomized block design experiment. The treatments were: chopped oaten hay diet at 90% of ad libitum intake without urea (L); the ciet offered at the same level as for L with urea infused into the rumen at 11.5 g kg-1 dry matter intake (LU); and the diet offered at 90% of the ad libitum intake achieved with urea infused at 11.5 g kg-1 dry matter intake (HU). Sheep given HU consumed 37% more (P < 0.01) organic matter (OM) than those fed L or LU, but the apparent digestibility of OM did not vary (59.2-61.8%) between treatments. The addit onal food consumption was associated with c. 20% increase (P < 0.05) in the weight of OM in the reticulorumen and significantly higher (by 10-35%; P < 0.05) fractional outflow rates of most dietary and microbial constituents of digesta. The fractional digestion rate of potentially digestible plant cell walls was not affected by urea, but the flow of microbial non-ammonia nitrogen from the abomasum was enhanced (L, 7.0; LU, 8.2; HU, 12.5 g day-1; P < 0.05). The results of this study suggest that the stimulatory effect of urea upon food intake was associated with the provision of additional microbial protein for digestion in the intestines, rather than changes in the rate or extent of organic matter fermentation in the reticulorumen.


Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 3873
Author(s):  
Natasha Kapoor ◽  
Werd al Najim ◽  
Camilo Menezes ◽  
Ruth K Price ◽  
Colm O’Boyle ◽  
...  

Long-term reductions in the quantity of food consumed, and a shift in intake away from energy dense foods have both been implicated in the potent bariatric effects of Roux-en-Y gastric bypass (RYGB) surgery. We hypothesised that relative to pre-operative assessment, a stereotypical shift to lower intake would be observed at a personalised ad libitum buffet meal 24 months after RYGB, driven in part by decreased selection of high energy density items. At pre-operative baseline, participants (n = 14) rated their preference for 72 individual food items, each of these mapping to one of six categories encompassing high and low-fat choices in combination with sugar, complex carbohydrate or and protein. An 18-item buffet meal was created for each participant based on expressed preferences. Overall energy intake was reduced on average by 60% at the 24-month buffet meal. Reductions in intake were seen across all six food categories. Decreases in the overall intake of all individual macronutrient groups were marked and were generally proportional to reductions in total caloric intake. Patterns of preference and intake, both at baseline and at follow-up appear more idiosyncratic than has been previously suggested by verbal reporting. The data emphasise the consistency with which reductions in ad libitum food intake occur as a sequel of RYGB, this being maintained in the setting of a self-selected ad libitum buffet meal. Exploratory analysis of the data also supports prior reports of a possible relative increase in the proportional intake of protein after RYGB.


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