scholarly journals Early life undernutrition in rats

1982 ◽  
Vol 47 (3) ◽  
pp. 417-431 ◽  
Author(s):  
K. S. Bedi ◽  
A. R. Birzgalis ◽  
M. Mahon ◽  
J. L. Smart ◽  
A. C. Wareham

1. Male rats were undernourished either during the geslational and suckling periods or for a period of time immediately following weaning. Some rats were killed at the end of the period of undernutrition; others were nutritionally rehabilitated for lengthy periods of time before examination. Two muscles, the extensor digitorum longus (EDL) and soleus (SOL) were studied from each rat. Histochemically-stained transverse sections of these muscles were used to determine total number of fibres, the fibre cross-sectional areas and the relative frequency of the various fibre types.2. All rats killed immediately following undernutrition showed significant deficit sin body-weight, muscle weight and fibre cross-sectional area compared to age-matched controls.3. Animals undernourished during gestation and suckling and then fed normally for 5 months showed persistent and significant deficits in body-weight, muscle weight and total fibre number. There were also significant deficits in mean fibre cross-sectional area of each fibre type except for red fibres in the EDL. No difference in the volume proportion of connective tissue was found.4. Rats undernourished after weaning and then fed ad lib. for approximately 7 months had normal body-and muscle weights. Their muscles showed no significant differences in total fibre number, relative frequency of the various fibre types, fibre size or volume proportion of connective lissue.5. These results indicate that, although the effects on rat skeletal muscle of a period of undernutrition after weaning can be rectified, undernutrition before weaning causes lasting deficits.

1999 ◽  
Vol 132 (1) ◽  
pp. 103-116 ◽  
Author(s):  
D. I. KRAUSGRILL ◽  
N. M. TULLOH ◽  
W. R. SHORTHOSE ◽  
K. SHARPE

Three successive experiments, of similar design, were carried out during 1986–88 at Mount Derrimut, Australia. Mature Merino ewes were mated to Poll Dorset rams and then allocated to either a control group (C) or a treatment group (R). Ewes from each treatment were slaughtered 60, 70, 100 or 140 days post-conception and the development of their foetuses was compared in terms of body size and muscle characteristics. In Expts 1 and 2, some ewes were allowed to lamb and the progeny in each group were slaughtered after reaching a body weight of 35 kg, for comparison of growth rates, muscle characteristics and meat quality.In each experiment, treatment extended from mating to day 70 of pregnancy and, during this period, both groups were housed. Ewes in group C were kept as one group and fed ad libitum and ewes in group R were individually penned and fed a restricted ration of the same diet as that given to group C in order to achieve a steady loss of body weight. In Expt 1, this loss was 8 kg but, in Expts 2 and 3, feed intake was controlled according to condition score and, during this period, group R ewes lost 25–35% of their body weight at mating. After day 70, all ewes were kept grazing and were offered supplementary feed at rates sufficient for a steady increase in ewe body weights.Foetuses in group R were lower in body weight (P<0·05), crown-rump length (P<0·05) and girth (P<0·01). However, birth weights and mean ages of the 35 kg lambs at slaughter did not differ significantly between treatments.There were no significant differences between treatments for the semitendinosus (ST) and semimembranosus (SM) muscles in total muscle weight, DNA content, protein content, nor in the ratios of muscle weight[ratio ]DNA and protein[ratio ]DNA. However, there were significant differences between experiments, which indicated that cell size in the ST and SM muscles was lower in Expt 2 than in Expt 1.In day 70 foetuses, the cross-sectional area of α fibres was greater (P<0·05) in group R than in group C but by day 140 the difference was no longer significant. At day 70, there was also a positive correlation (r=0·65, P<0·01) between the cross-sectional area of β fibres and the number of α fibres surrounding each of them. There were no significant differences between treatments at any age in the percentages of βR, αR and αW fibres.Meat from group R lambs was more tender than that from group C lambs as indicated by significantly lower means in the SM muscle for adhesion (P<0·01) and Warner–Bratzler Peak Force (WB PF) measurements (P<0·05).Although some effects of nutritional restriction were found, severe feed shortage in early pregnancy in sheep is unlikely to have significant effects on the production of prime lamb meat provided that adequate nutrition is available during late pregnancy and post-natal growth.


1998 ◽  
Vol 84 (4) ◽  
pp. 1407-1412 ◽  
Author(s):  
G. E. McCall ◽  
D. L. Allen ◽  
J. K. Linderman ◽  
R. E. Grindeland ◽  
R. R. Roy ◽  
...  

The purpose of this study was to determine the effects of functional overload (FO) combined with growth hormone/insulin-like growth factor I (GH/IGF-I) administration on myonuclear number and domain size in rat soleus muscle fibers. Adult female rats underwent bilateral ablation of the plantaris and gastrocnemius muscles and, after 7 days of recovery, were injected three times daily for 14 days with GH/IGF-I (1 mg/kg each; FO + GH/IGF-I group) or saline vehicle (FO group). Intact rats receiving saline vehicle served as controls (Con group). Muscle wet weight was 32% greater in the FO than in the Con group: 162 ± 8 vs. 123 ± 16 mg. Muscle weight in the FO + GH/IGF-I group (196 ± 14 mg) was 59 and 21% larger than in the Con and FO groups, respectively. Mean soleus fiber cross-sectional area of the FO + GH/IGF-I group (2,826 ± 445 μm2) was increased compared with the Con (2,044 ± 108 μm2) and FO (2,267 ± 301 μm2) groups. The difference in fiber size between the FO and Con groups was not significant. Mean myonuclear number increased in FO (187 ± 15 myonuclei/mm) and FO + GH/IGF-I (217 ± 23 myonuclei/mm) rats compared with Con (155 ± 12 myonuclei/mm) rats, although the difference between FO and FO + GH/IGF-I animals was not significant. The mean cytoplasmic volume per myonucleus (myonuclear domain) was similar across groups. These results demonstrate that the larger mean muscle weight and fiber cross-sectional area occurred when FO was combined with GH/IGF-I administration and that myonuclear number increased concomitantly with fiber volume. Thus there appears to be some mechanism(s) that maintains the myonuclear domain when a fiber hypertrophies.


1996 ◽  
Vol 8 (3) ◽  
pp. 391 ◽  
Author(s):  
MD Fratacci ◽  
M Levame ◽  
A Rauss ◽  
H Bousbaa ◽  
G Atlan

The changes occurring in the histochemical characteristics of the rat diaphragm during the postnatal period were examined. Fibre-type distribution, fibre oxidative capacity, i.e. succinate-dehydrogenase (SDH) activity, and cross-sectional area were compared in the costal (COS) and crural (CRU) regions, and across their abdominal and thoracic surfaces. The proportions of type I and IIb fibres in both COS and CRU increased with age, while the proportion of type IIa fibres progressively decreased. For COS, fibre distribution was homogeneous over the entire muscle and did not change after 4 weeks. For CRU, it was heterogeneous with a higher proportion of type I fibres on the thoracic surface as from the first week. All fibre types significantly increased in cross-sectional area between 1 and 8 weeks, with no significant differences in COS and CRU. Mean SDH activity did not differ between COS and CRU or across the muscles. Mean SDH activities-were low and identical in all fibre types at birth, and then increased, peaking at the 6th week in type I and IIa fibres. When total muscle fibre oxidative capacity was calculated from an index including fibre-type proportion, cross-sectional area and mean SDH activity, it was significantly higher at 1 than at 8 weeks after birth; this might have functional implications for the newborn.


2020 ◽  
Author(s):  
Gabriel Cao ◽  
Julián González ◽  
Juan P. Ortiz Fragola ◽  
Angélica Muller ◽  
Mariano Tumarkin ◽  
...  

AbstractIn previous studies, we reported evidence showing that chronic cola consumption in rats impairs pancreatic metabolism of insulin and glucagon and produces some alterations typically observed in the metabolic syndrome (i.e, hyperglycemia, and hypertriglyceridemia) with an increase in oxidative stress. Of note, no apoptosis nor proliferation of islet cells could be demonstrated. In the present study, 36 male Wistar rats were divided in three groups to freely drink regular cola, light cola, or water (controls). We assessed the impact of the three different beverages in glucose tolerance, lipid levels, creatinine levels and immunohistochemical changes addressed for the expression of insulin, glucagon, PDX-1 and NGN3 in islet cells, to evaluate the possible participation of PDX-1 in the changes observed in α and β cells after 6 months of treatment. On the other hand, we assessed by stereological methods, the mean volume of islets (Vi) and three important variables, the fractional β-cell area, the cross-sectional area of alpha (A α-cell) and beta cells (A β-cell), and the number of β and α cell per body weight.Cola drinking caused impaired glucose tolerance as well as fasting hyperglycemia and increase of insulin immunolabeling. Immunohistochemical expression for PDX-1 was significantly high in regular cola consumption group compared to control. In this case, we observed cytoplasmatic and nuclear localization. Likewise, a mild but significant decrease of Vi was detected after 6 months of cola drink consumption compared with control group. Also, we observed a significant decrease of fractional β cell area compared with control rats. Accordingly, a reduced mean value of islet α and β cell number per body weight compared to control was detected. Interestingly, consumption of light cola increased the Vi compared to control. In line with this, a decreased cross-sectional area of β-cells was observed after chronic consumption of both, regular and light cola, compared to controls. On the other hand, NGN3 was negative in all three groups. Our results support for the first time, the idea that TDX-1 plays a key role in the dynamics of the pancreatic islets after chronic consumption of sweetened beverages. The loss of islets cells might be attributed to autophagy, favored by the local metabolic conditions.


1993 ◽  
Vol 74 (2) ◽  
pp. 742-749 ◽  
Author(s):  
D. J. Prezant ◽  
D. E. Valentine ◽  
H. H. Kim ◽  
E. I. Gentry

The effects of 4.5 days of acute starvation, either alone or followed by refeeding (ad libitum), on diaphragm contractility, fatigue, and fiber types were studied in male rats. Contractility and fatigue resistance indexes were measured in an in vitro costal diaphragm strip preparation with direct stimulation at 37 degrees C. Compared with controls, starvation produced a 28 +/- 1% (P < 0.001) reduction in body weight and an 18 +/- 4% (P < 0.001) reduction in costal diaphragm weight. Twitch and tetanic tensions (normalized for weight or cross-sectional area) were not reduced by starvation. Starvation produced significant increases in fatigue resistance indexes after a 5-Hz stimulation paradigm but not after a 100-Hz paradigm, supporting the hypothesis that fatigue resistance is dependent on the energy demand of a given paradigm. The proportions of type I and type II fibers were similar between diaphragms of starved and control rats, but the cross-sectional area of type II fibers decreased significantly by 18 +/- 7% (P < 0.01). Thus, despite the significant decrease in diaphragm weight after starvation, contractility was preserved and fatigue resistance was increased (low-output paradigm). This is consistent with the decrease in type II fiber area. Refeeding restored all parameters so that there were no longer significant differences in body or diaphragm weight, contractility, fatigue, or fiber types.


1956 ◽  
Vol 7 (6) ◽  
pp. 574 ◽  
Author(s):  
RH Watson ◽  
CS Sapsford ◽  
I McCance

Observations were made on 110 Merino rams aged between 1 and 64 weeks. They comprised four groups, the animals of which experienced different rates of growth. The weight of the testes a t any one age varied widely. It was closely related to body weight. This relation was similar in all groups. As body weight increased from 23 to 27 kg, the relative increase in the weight of the testes was much greater than that a t higher or lower body weight. The general histological characteristics of the testes were closely related to their weight, and, like it, to body weight. The tubules were present as solid or but slightly vacuolated cords in all animals which weighed less than 21 kg. Spermatozoa were not seen in the lumen of the tubules in any animal which weighed less than 27 kg, and they were present in all but three of those which weighed more than 28 kg. The relative cross-sectional area of the seminiferous tubules increased directly with the relative increase in the weight of the testes until the testes weighed at least 300 g. The weight of the epididymides was more closely related to the weight of the testes than to age or body weight. Its relation to the weight of the testes varied in the different groups. Irrespective of the age a t which the particular body weight was attained, little separation of the prepuce from the penis had occurred in animals which were lighter than 18 kg, and separation was more or less complete in most animals which were heavier than 27 kg.


1985 ◽  
Vol 58 (4) ◽  
pp. 1354-1359 ◽  
Author(s):  
S. G. Kelsen ◽  
M. Ference ◽  
S. Kapoor

The present study examined the effect of prolonged undernutrition on diaphragmatic structure and force-generating ability. Studies were performed on 58 Syrian hamsters in which the feed was reduced by 33% for a 4-wk period. Sixty animals fed a similar diet ad libitum served as controls. Diaphragm muscle structure was assessed from its mass (wet and dry weight), thickness, fiber composition, and fiber size. Isometric force produced in vitro by isolated muscle strips in response to electrical stimulation of the phrenic nerve was examined over a range of muscle lengths (length-tension relationship). In undernourished animals, body weight decreased 25 +/- 5%. Diaphragm wet and dry weight, muscle thickness, and the cross-sectional area of fast-glycolytic (FG) and fast-oxidative (FO) fibers were significantly less in undernourished than control animals and correlated with reductions in body weight. The cross-sectional area of slow-oxidative (SO) fibers was the same in the two groups. The percentage of FG fibers in undernourished animals was decreased slightly and the percentage of SO fibers increased. Maximum isometric tension was reduced in undernourished animals as compared with controls, but the position and shape of the length-tension relationship was the same in the two groups. Reductions in muscle force appeared to be explained by decreases in muscle mass, since tension corrected for cross-sectional area or tissue weight was the same in the two groups. Therefore muscle mechanical efficiency appeared to be unaffected by undernutrition. These data indicate that prolonged undernutrition causes deleterious changes in diaphragm muscle structure that impair its ability to generate force.


1960 ◽  
Vol 11 (5) ◽  
pp. 851 ◽  
Author(s):  
AE Henderson ◽  
BI Hayman

Investigation has been made of the influence of fibre number per unit area (N), cross-sectional area of fibre (A), and fibre length (L), on wool production per unit area of skin (W). The influence of the compound characters fibre volume (V) and proportion of skin area occupied by fibre (0) has also been considered. Methods are given whereby the significance of the variation associated with any one of these interacting components can be assessed. Data from four groups of lambs were analysed, each group having been subjected to a different nutritional regime. Slightly more than three-quarters of the variation induced in W by these treatments was due to variation in L, with N and A having negligible effects. No evidence was found that the relative influence of the components changed with change in level of production. Differences in W between lambs on the same nutritional level were influenced almost equally by variation in N and L, with A again having a negligible effect. Of the variation in W between positions on lambs, approximately 50 per cent. was accounted for by variation in N, 40 per cent. by variation in A, and 10 per cent. by variation in L. Variation of the compound character O accounted for nearly 90 per cent. of the variation in W over the body.


2014 ◽  
Vol 44 (11) ◽  
pp. 2045-2051
Author(s):  
Kátia de Oliveira ◽  
Ricardo Velludo Gomes de Soutello ◽  
Ricardo da Fonseca ◽  
Andréa Machado Lopes ◽  
Paulo César da Silva Santos ◽  
...  

This study aimed to evaluate the use of Pessoa's rein in training equine, as a support in exercise training, on biometry by ultrasonography of the epaxial (Longíssimus Dorsi, Gluteus Medius e Musculus Multifidus) and pelvic musculature (Biceps Femoris e Semitendinosus). Thereby, eight Quarter Horse mares was used, with eight years on average age, 400kg of body weight, trained with the Pessoa's rein twice a week, for two months. Variables were measured before and after training, consisting of assessment thickness (cm) of the Longíssimus Dorsi and cross-sectional area (cm2) of muscles, Gluteus Medius, Biceps Femoris, Semitendinosus and Musculus Multifidus. It observed a significant effect of training with Pessoa's rein, on the Biceps Femoris (P<0.01) and Musculus Multifidus (P<0.01), which the average cross-sectional area at the final evaluation were of 28.66cm2 and 14.29cm2, respectively. Thus it can be conclude that training with Pessoa's rein modifies muscular function, promoting hypertrophy Musculus Multifidus and Biceps Femoris of horses


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