Quantitative analysis of the neurons from the myenteric plexus in the ileum of rats submitted to severe protein deficiency / Análise quantitativa dos neurônios do plexo mientérico do íleo de ratos submetidos a intensa carência de proteínas

The effects of protein malnutrition on the quantitative aspects of the myenteric plexus in the ileum of adult Rattus norvegicus were assessed. Thirty 90-day-old rats were divided into two groups: Control Group (CG, n=15) and Experimental Group (EG, n=15). The CG received 26 percent protein chow and the EG received 4 percent protein chow for 90 days. At the end of the experiment, the animals from the CG weighed 369.63±26.33, and the ones from the EG 215.34±56.31. The ileum was submitted to Giemsa, NADH- and NADPH-diaphorase technique in order to evidence nervous cells in the whole-mount preparations. Animals from the EG presented a 41.75 percent body weight loss in relation to the CG as well as 17.6 percent length reduction for the ileum-jejunum. Moreover, the organ was 41 percent lighter for the EG. Giemsa-stained neurons were 17.02 percent more concentrated in the EG (p>0.05). NADH-diaphorase-stained neurons were 26.6 percent more concentrated in the EG (p<0.05), while the NADPH-diaphorase were 26.28 percent more concentrated in this group (p<0.05).

Avaliou-se o efeito da desnutrição protéica sobre o número de neurônios mientéricos do íleo de ratos adultos. Foram utilizados 30 animais (90 dias de idade), divididos em dois grupos: controle (GC, n=15) e experimental (GE, n=15), sendo oferecido ao GC ração com teor protéico de 26 por cento e, para o GE, ração com 4 por cento de proteína, durante 90 dias. Os animais do grupo controle pesaram 369,63±26,33g e o experimental 215,34±56,31g. Preparados de membrana do íleo foram submetidos à técnica de Giemsa, NADH- e NADPH-diaforase. Os animais do GE apresentaram perda de peso de 41,75 por cento, em relação ao GC e redução do comprimento do jejuno-íleo de 17,6 por cento, além disso, o órgão apresentou-se 41 por cento mais leve no GE. Os neurônios corados com a técnica de Giemsa apresentaram-se 17,02 por cento mais concentrados no GE (p>0,05). Os neurônios NADH-diaforase apresentaram-se 26,60 por cento mais concentrados no GE (p<0,05). E os neurônios NADPH-diaforase apresentaram-se 26,28 por cento mais concentrados neste grupo (p<0,05).

Efecto de la diarrea sobre la utilización de nutrientes en ratas con desnutrición proteico-calórica o proteica / Effect of diarrhea on nutrient utilization in protein deficient or protein-calorie deficient rats

La diarrea magnifica los efectos de la desnutrición. En consecuencia, aquí se estudió el efecto de la diarrea sobre dos tipos de desnutrición (proteica y proteico-calórica). El experimento incluyó 42 ratas jóvenes de la cepa Sprague Dawley que se distribuyeron en tres grupos (14 ratas/grupo). Durante los primeros 16 días del experimento, el primer grupo recibió una dieta control ad-libitum, el segundo recibió la misma dieta pero su consumo se redujo en un 50% y el tercer grupo recibió una dieta deficiente en proteína. Al final de este período había ratas bien nutridas (controles) y con desnutrición proteica y calórico-proteica. Luego, a la mitad de estas ratas en cada grupo, se les produjo diarrea con lactosa y todas las ratas continuaron con su dieta y el régimen de alimentación preasignado durante una semana. Así, durante este período había ratas controles así como con deficiencia proteica o calórico-proteica que tenían diarrea y grupos idénticos que no tenían diarrea. Los resultados mostraron que la diarrea causó una disminución del consumo y del crecimiento en las ratas del grupo control y deficiente en proteína. Sin embargo, el grupo con deficiencia calórico-proteica no redujo su consumo ni disminuyó su crecimiento en respuesta a la diarrea. La consecuencia de esto fue que la diarrea produjo desnutrición en el grupo control y aumentó la desnutrición en el grupo deficiente en proteína, pero no tuvo un efecto adicional en el grupo con deficiencia calórico-proteica. Además, la reducción en la absorción aparente del nitrógeno y de la grasa asociada con la diarrea, fue mayor en las ratas deficientes en proteína. Este grupo también presentó las actividades más bajas de disacaridasas intestinales. Esto resultados muestran que la diarrea tiene un efecto negativo mayor en ratas con deficiencia proteica que con deficiencia calórico-proteica.

Diarrhea increases the effects of malnutrition. Accordingly, the effect of diarrhea on two types of malnutrition (protein deficiency and protein-calorie deficiency) was studied. The experiment included 42 young Sprague Dawley rats. The rats were distributed into three groups with 14 rats per group. During the first 16 of the experiment, the first group was fed a control diet ad libitum, the second received the same diet but with food intake reduced in 50% whereas the third group was offered a protein deficient diet. Thus, at the end of this period there were well-fed rats (control), as well as protein and protein-calorie malnourished rats. Then one half of the rats in each group were given lactose to produce diarrhea and all rats continued with their previously assigned diet and feeding regime during one more week. Therefore, during this period there were control rats, protein deficient rats and protein-calorie deficient rats with and without diarrhea. The results showed that diarrhea caused a substantial reduction in food intake and growth in the well-fed rats and also in the group fed the protein deficient diet. However, the protein-calorie deficient group did not reduce its intake nor its growth rate. As a result, diarrhea caused malnutrition in the control group and increased malnutrition in the protein deficient but it did not have an additional effect in the protein-calorie deficient rats. The apparent absorption of lipids and nitrogen measured in these rats showed that the absorption reduction caused by diarrhea was more pronounced in the protein deficient group. This group also had the lowest activities of intestinal disaccharidases. These results showed that diarrhea had a more detrimental effect in protein deficient than in protein-calorie deficient rats.

Phospholipid metabolism and protein kinase C mediated protein phosphorylation in dietary protein deficiency in rat lung.

Nutritional deprivation of proteins decreases the protein kinase C (PKC) activity in rat lung. The activity of (PKC) is influenced by lipid metabolism. Changes in PKC activity may influence phosphorylation of its substrate proteins in the tissues. Therefore, alterations in phospholipid metabolism and PKC mediated protein phosphorylation in dietary protein deficiency in rat lung were envisaged. The study was conducted on rats fed on three different types of diet viz., casein (20% protein), deficient (4% protein, rice flour as source of protein) and supplemented (deficient diet supplemented with L-lysine and DL-threoning). Feeding of protein deficient diet caused reduction in incorporation of [3H] myo-inositol in the total phosphoinositides in lungs and an increase in total inositol phosphate pool. There was a significant reduction in the contents and turnover rate of phosphatidyl inositol and phosphatidyl inositol monophosphate. Supplementation of diet with L-lysine and DL-threonine had a reversing effect on total pool of phosphoinositides and, the metabolism of phosphatidyl inositol bisphosphate and phosphatidyl inositol. In phosphatidyl choline metabolism, the dietary protein deficiency led to a decrease in incorporation of [14C-methyl] choline-chloride in total phospholipids. In contrast, its incorporation increased in phosphatidyl choline pool. The contents of phosphatidyl choline and residue, incorporation of [14C-methyl] choline-chloride in them and their turnover rate also increased. Supplementation of diet had a reversal effect on most of these parameters. Phosphorylation of proteins of 84, 47, 35 and 16 kDa was identified to be mediated by PKC. In dietary protein deficiency, phosphorylation of all these proteins, except that of 47 kDa, increased. Supplementation of diet reversed the pattern except that of 84 kDa. The findings suggest that changes in phospholipid metabolism in dietary protein deficiency may effect the activity of PKC thereby influencing the phosphorylation of its substrate proteins and hence associated functions that may lead to pathophysiology of lung.

Biokinetics of 65Zn in liver and whole body and its bio-distribution in nickel treated protein deficient rats.

This study was designed to determine the effect of nickel treatment on biological half-lives of 65Zn in whole body and liver as well as on distribution of 65Zn in different organs of protein deficient rats. Nickel sulfate at a dose level of 800mg/l in drinking water was administrated to normal control as well as to protein deficient rats for 8 weeks. A significant increase was found in fast and slow components of biological half lives of 65Zn in whole body and only fast component in liver of protein deficient rats. Interestingly, slow component in whole body and fast component in liver of nickel treated protein deficient rats were not different from normal controls though they were significantly elevated in protein deficient rats. On the other hand, slow component of 65Zn was also not altered in nickel treated protein deficient rats, which however, was significantly decreased in nickel treated rats. Protein deficiency led to a marked elevation in per cent uptake of 65Zn in brain and caused significant depression in liver, kidney and intestine. However, uptake of 65Zn in brain showed a significant depression in nickel treated rats, whereas the uptake was elevated in brain in nickel treated protein deficient rats. In conclusion, protein deficient conditions seem to be playing a dominant role in context with the distribution of 65Zn in different organs when nickel is administered to protein deficient rats. However nickel alone is seen to cause adverse effect on the distribution of 65Zn.

Effects of protein and vitamin B deficiency on blood parameters and myenteric neurons of the colon of rats

The aims of this work were to evaluate the effects of the deficient ingestion of protein and vitamin B on the biochemical and hematologic parameters and on the NADH- and NADPH-diaphorase positive myenteric neurons. The control animals (n=10) received commercial chow and the experimental rats (n=10) received chow with protein level reduced to 8 percent during 120 days. At the time of killing blood was collected for assessment of the blood and hematologic parameters and the ascending colon for quantitative analysis of the neurons of the myenteric plexus. It was observed that the reduction of the protein level to 8 percent coupled to the reduction of the levels of vitamin B in adult rats neither led to qualitative or quantitative changes on red or white blood cells, nor decreased globulin levels, induced the formation of edema or gave rise to clinical signs typical of protein or vitamin B deficiency. On the other hand, the experimental protocol led to less weight gain, change on the body composition with fat deposition; decrease of the values of serum total protein and albumin; reduction of the area of colon and density of nitrergic and NADH-diaphorase myenteric neurons inferior to the expected

IgA B and T cells in the intestinal villi of immunodeficient rats orailly treated with thymomodulin

Previous studies on the effect of the oral administration of bacterial immunomodulators (IM-104 and RN-301) during the protein free diet period, have shown an increase on B and T cell gut repopulation, accompanied by IgA antibody production. The usefulness of oral administration of the immunomodulator thymomodulin (TmB) during the protein refeeding period was investigated. TmB allowed the recovery of a normal repopulation of gut lamina propria with IgA B and CD5 T cells and decreases to control values the number of activated intraepithelial lymphocytes (CD25+T cell subset). Therefore, the oral administration of TmB may be useful as a therapeutic agent as it seems to improve the repopulation of intestinal villi with immunocompetent cells. Also, it seems to regulate the immunosurveillance at the epithelium level as it increases the CD5+T cells but decreases the activated ones.

Effects of protein deficiency and natural intestinal infection with Giardia lamblia on jejunal intraepithelial lymphocytes in rats of different ages

1. The interaction between experimental protein deprivation and natural intestinal infection by Giardia lamblia was studied in terms of its effects on the intraepithelial lymphocyte (IEL) population and morphology of the jejunal mucosa of rats of different ages. 2. Young, adult and old male Wistar rats received a protein-deficient diet (2 casein) or a control diet (20 casein) for 42 days. Mucosal height and the number of lymphocytes located among 500 consecutive epithelial cells (EC) along the villi or crossing the basement membrane were determined in PAS-stained jejunal fragments. 3. The number of IEL increased progressively with animal age, from 14 to 25 per 100 epithelial cells, with significant differences between age ranges. However, the number of IEL did not differ between control and protein-deficient rats in any of the age groups. The proportion of lymphocytes crossing the basement membrane was approximately two-fold greater in young (2.8/100 EC) and adult (5.8/100 EC) protein-deficient animals than in their respective controls (1.6 and 2.8/100 EC). The intensity of parasite colonization was moderate, from 3 to 5/100 EC and did not differ between groups. The pattern of morphologic changes of jejunal mucosa in protozoal infection did not differ between control and protein-deficient animals in any of the three age groups. 4. We conclude that intestinal infection with Giardia lamblia probably stimulated the local immune response, masking the reduction of the IEL population induced by protein deficiency. The increase in lymphocyte numbers with age may be related to prolonged antigenic stimulation promoted by infection.

'Dark' cell formation under protein malnutrition: process of conversion and concept of 'semi-dark' type Purkinje cells.

This paper deals with some deleterious effects of protein malnourishment in rat cerebellum. Severe protein deprivation enhanced the formation of 'dark' cells in white rats. It is postulated that abnormal changes in the neuronal contents induced by nutritional stress play a vital role in the formation of the 'dark' cells through an intermediary stage, 'semi-dark' cells. Centrophenoxine a lipofuscinolytic agent, however, seems to interfere with the process of formation of 'dark' cells and/or helps reconversion of the 'dark' cells into the normal or 'light' type Purkinje cells.

Hepatic plasma membrane fluidity and dietary proteins.

Effect of protein deficient diet on hepatic plasma membrane fluidity has been studied in rats using (i) steady state fluorescence polarization and anisotropy, (ii) phospholipid and cholesterol contents, (iii) phospholipid fatty acid composition, (iv) turnover of phosphatidyl choline (PC), and (v) activities of membrane-bound enzymes as parameters and rats fed casein (20%) diet as standard group. A significant increase in steady state fluorescence and anisotropy values was registered in the deficient group, indicating increased resistance and hence decrease in fluidity of the plasma membrane. Supplementation of the diet with lysine and threonine improved these values, thereby suggesting the significance of diet for membrane fluidity. Simultaneous significant alterations in other parameters, viz. (i) decrease in PC, PE and free cholesterol and increase in esterified cholesterol contents, (ii) decrease in unsaturation of fatty acids of PC, (iii) decrease in incorporation of NaH2 32PO4, [CH3-14C]choline and [CH3-14C]methionine into plasma membrane PC, and (iv) decrease in activities of plasma membrane 5'-nucleotidase and phosphodiesterase along with increase of (Na(+)-K+)ATPase and adenyl cyclase, were observed in the deficient group which on supplementation with lysine and threonine showed improvement over alterations.

Changes in macrophage membrane proteins in relation to protein deficiency in rats.

Resident and thioglycollate (TG) macrophages were isolated from rats fed 20 and 4% protein diets. These cells were cultured for 2 and 18 hr; further the membrane proteins were separated by SDSPAGE. Though basically all the samples had a similar banding pattern, the protein profile was very complex in nature. TG elicited macrophages from the protein fed group had increased contents of high molecular weight proteins compared to the resident cells from both the groups as well as TG cells from the protein deficient group. The difference increased with prolonged incubation. Polypeptides at 56.5 and 46 kd which were prominently present in the control samples, was very low in the protein deficient ones. Bands at 34, 32, 27 to 19.5 kd were reduced in the TG cells from the protein fed group. The protein deficient samples exhibited a strong band at 43 kd (presumably actin) while it was present in very small amounts in the cells from the protein fed groups. These observations indicate that the protein restriction had down regulated TG induced modulation of macrophage membrane proteins to the level of resident cells which are physiologically in a lower state of activation. These changes could reflect on their reduced functional properties.

Effects of protein restriction on functional properties of rat peritoneal macrophages.

Rats were maintained on 20% and 4% protein diets for 3 weeks. The functional properties of thioglycollate (TG) elicited macrophages from these groups were compared with the non elicited resident cells from the protein fed group. Elicitation of macrophages in response to TG was low in the protein deficient group. These cells also exhibited low adherence in overnight cultures compared to those isolated from the protein fed group; however their viability and total protein content remained unaltered. Normal resident and TG elicited cells from 4% protein fed group exhibited an initial lag period in H2O2 production in response to zymosan stimulation. The lag period could be correlated to the high endogeneous catalase activity in these cells. Incubation with zymosan resulted in rapid decline in catalase levels, facilitating evolution of H2O2. On prolonged incubation, the elicited cells from the protein fasted rats evolved about 87% H2O2 compared to the protein fed samples. In the absence of zymosan all the samples possessed comparable NADPH oxidase activity. Zymosan induced activation of this enzyme was higher in TG cells from the protein fed groups, compared to the protein fasted and the resident samples. The cellular enzyme activity, however was not altered in the TG cells of both the groups though it declined rapidly in the corresponding resident cells. Significant reduction (congruent to 50%) in both serum iron and transferrin in the low protein fed samples did not correspondingly affect the oxidative burst process. However the engulfment of yeast cells was greatly impaired due to protein restriction. Adherence and phagocytic properties of macrophages are regulated by the activity of their membrane constituents.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of feeding low protein diet with and without leucine supplementation on protein status of lactating females and their pups.

Female rats were fed low protein diet (10% casein) either as such or supplemented with 3% leucine during pregnancy and lactation. Changes in litter size and the survival rate, growth and protein status of the pups were noted. The milk yield and hepatic and mammary gland protein status of the mothers were also studied. Feeding low protein diet reduced litter size, increased their mortality and resulted in poor growth of the pups. It also resulted in poor hepatic and mammary gland protein status of the mothers, as well as reduced their milk yield. On adding 3% leucine to 10% casein in the diet, the changes observed in the low protein group, did not alter in any manner.

Effect of nutritional status on mutagenicity of urine excreted by rats treated with standard/experimental carcinogens.

Urine samples, collected from Sprague Dawley rats treated with extracts of tobacco/masheri, benzo (a) pyrene, N'-nitrosonornicotine, N'-nitrosodiethylamine and maintained on semi-synthetic diets sufficient or deficient in Vitamin A, B and protein were tested for mutagenicity using Salmonella/microsome assay. The mutagenic activity of urine or various treated groups was in the order deficient diet greater than standard laboratory diet greater than nutritionally sufficient diet. Present results confirmed the earlier observations that nutritionally deficient animals are likely to have more exposure to mutagenic metabolites that are generated by increased phase I enzymes and decreased detoxification system.

Acetylcholine levels of rat brain and heart in starvation and protein restriction.

Acetylcholine (ACh) levels and protein content in brain and heart were determined in normal, acutely starved, chronically semi-starved and chronically protein restricted groups of adult male rats. The only change observed in acute starvation and chronic semi-starvation was an increase in ACh level with a decrease in protein content in the heart, no change was observed in the brain. Protein restriction, however, produced a significant rise in ACh levels with a decrease in protein content of both brain and heart.

Effect of protein deprivation and subsequent rehabilitation on the intestinal transport of L-methionine in vivo.

The effect of protein deprivation and subsequent rehabilitation on the intestinal transport of L-methionine was studied in albino rats of both sexes. The rats given diet containing no protein or 3 per cent maize protein for 28 days, lost their intestinal cell population by 50 and 20 per cent respectively. The net absorption rate of L-methionine was little affected, while absorptive capacity of intestinal cells was considerably enhanced in protein-deficient rats. The increase in absorptive capacity of intestinal cells was much higher in rats given protein-free diet than in those given maize diet. The augmentation is absorptive capacity of intestinal cells of protein-deprived rats was a temporary adaptation to the conditions that prevent the formation of new cells. Rehabilitation of malnourished rat on diet containing 17 per cent casein, resulted in a rapid increase in intestinal cell population, return of the absorptive capacity of intestinal cells to normal, and augmentation in net absorption rates.