Effects of Preweaning Undernutrition and Continued Postweaning Protein Deficiency or Nutritional Rehabilitation on Polyphosphoinositides in Rat Brain

Metabolically inert polyphosphoinositides seem to play an important role in the structural development of neurons, glia, and myelin. The metabolically active pool of PhIpp appears to be important for the functional development of glia and myelin during the postweaning period, whereas PhIp seems to be more important for the functional development of neurons during the preweaning period. Neonatal undernutrition reduces the concentrations of structural polyphosphoinositides and metabolic PhIp while metabolic PhIpp remains unaltered. These effects can be reversed by postweaning nutritional rehabilitation. A continued postweaning protein deficiency of neonatally undernourished rats affects structural PhIpp more than PhIp. Metabolically active PhIpp is drastically reduced.     

DNA,RNA, protein and DNases in developing rat cerebellum: Effects of early postnatal nutritional deprivation

The effect of early postnatal undernutrition and subsequent rehabilitation on wet weight, DNA, RNA, protein and the activities of acid and alkaline DNases in the cerebellar region of rat brain was studied. The cerebellar region was found to be affected significantly during early undernutrition. Further, earlier the initiation of nutritional rehabilitation the better was the recovery and in some cases timely nutritional rehabilitation resulted in better than normal biochemical composition of the brain. The specific activities of acid and alkaline DNases were not affected by early undernutrition. However, the total activities of these enzymes were significantly low in undernourished rats (R1₁₅ and R₂₁) Rehabilitation of these deprived groups upto 150 days resulted in higher amounts of these enzymes as compared to those of age-matched controls. It is concluded that the two DNases, are synthesized in a preferential manner during rehabilitation, It is further concluded that cerebellar region, in terms of development schedule and response to imposed calorie restriction, is intermediary between grey and white matter regions.     

Early undernutrition increases glycogen content and reduces the activated forms of GSK3, AMPK, p38 MAPK, and JNK in the cerebral cortex of suckling rats

Exposure to maternal undernutrition during development increases the risk for neurological and cognitive defects. However, little is known about the underlying mechanisms involved. Peripheral responses to insulin are increased following food-restriction, thus the possibility arises that brain insulin actions are affected by undernutrition, causing damages to the higher cerebral functions. In this study, we examined the effects of early undernutriton on molecular targets of insulin actions such as glucose transporters, glycogen, glycogen synthase kinase-3 (GSK3) and mitogen-activated protein kinases, as well as proteins involved in apoptosis in the cortex from 10-day-old rats. We show that undernutrition results in an enhanced glycogen content which is confined to astrocytes, according to our histochemical approaches. Cortical phospho-GSK3 is also increased. In addition to glycogen synthesis, GSK3 regulates crucial cellular processes. Therefore, its elevated degree of phosphorylation may have an impact on these processes and, consequently, on the cortical development. Phospho-p38 and both total JNK and phospho-JNK, which regulate apoptosis, are reduced following undernutrition. However, cleaved caspase 3 is not altered, which suggests that this condition does not induce extensive modifications to the cortical apoptosis. Thus, our results indicate that undernutrition gives rise to molecular alterations that may have repercussions on cerebral cortex development and functions.     

Effects of maternal nutrient restriction during early or mid-gestation without realimentation on maternal physiology and foetal growth and development in beef cattle

The aim of this study is to determine the effects of early and mid-gestation nutrient restriction on maternal metabolites and foetal growth. Primiparous Angus cows were synchronized and inseminated with semen from one sire. Dietary treatments were: control to gain 1 kg/week (CON) or 0.55% maintenance energy and CP requirements (nutrient restricted; NR). A subset of dams was fed NR (n=8) or CON (n=8) from days 30 to 110 of gestation. Another group was fed CON (n=8), days 30 to 190; NR (n=7), days 30 to 110 followed by CON days 110 to 190; or CON, (n=7) days 30 to 110 followed by NR days 110 to 190. Cows were harvested at days 110 or 190 of gestation, when foetal measurements and samples were collected. Cows that were NR during days 30 to 110 or 110 to 190 of gestation lost significant BW and body condition score (P<0.001), this was associated with reduced plasma glucose during NR (P<0.002). Foetal weights, empty foetal weights, abdominal and thoracic circumferences were all reduced (P<0.03) in day 110 NR animals. Foetal perirenal adipose as a percentage of empty foetal weight was increased (P=0.01) in NR day 110 female foetuses compared with CON foetus. Maternal serum triglycerides at day 110 of gestation were decreased (P<0.05) in NR dams, whereas foetal serum triglycerides were increased (P<0.05) in response to maternal NR. Foetal weights tended to be reduced (P=0.08) in NR/CON and CON/NR v. CON/CON cattle at day 190 of gestation. Empty foetal weights, abdominal and thoracic circumferences were reduced (P⩽0.03) in NR/CON and CON/NR v. CON/CON cattle. Brain weight as a percentage of empty foetal weight was increased (P<0.001) in NR/CON and CON/NR v. CON/CON cattle. Foetal perirenal adipose as a percentage of empty foetal weight was increased (P=0.003) in NR/CON and CON/NR v. CON/CON cattle. Maternal serum triglycerides at day 190 of gestation were decreased (P<0.05) in association with maternal NR. Foetal serum triglycerides at day 190 of gestation were increased (P<0.05) in response to maternal NR during early gestation but decreased by NR in mid gestation compared with CON foetuses. The data show that maternal nutrient restriction during early or mid-gestation cause’s asymmetrical foetal growth restriction, regardless if the restriction is preceded or followed by a period of non-restriction.     

Low transformation growth factor-β1 production and collagen synthesis correlate with the lack of hepatic periportal fibrosis development in undernourished mice infected with Schistosoma mansoni

Undernourished mice infected (UI) submitted to low and long-lasting infections by Schistosoma mansoni are unable to develop the hepatic periportal fibrosis that is equivalent to Symmers’ fibrosis in humans. In this report, the effects of the host’s nutritional status on parasite (worm load, egg viability and maturation) and host (growth curves, biology, collagen synthesis and characteristics of the immunological response) were studied and these are considered as interdependent factors influencing the amount and distribution of fibrous tissue in hepatic periovular granulomas and portal spaces. The nutritional status of the host influenced the low body weight and low parasite burden detected in UI mice as well as the number, viability and maturation of released eggs. The reduced oviposition and increased number of degenerated or dead eggs were associated with low protein synthesis detected in deficient hosts, which likely induced the observed decrease in transformation growth factor (TGF)-β1 and liver collagen. Despite the reduced number of mature eggs in UI mice, the activation of TGF-β1 and hepatic stellate cells occurred regardless of the unviability of most miracidia, due to stimulation by fibrogenic proteins and eggshell glycoproteins. However, changes in the repair mechanisms influenced by the nutritional status in deficient animals may account for the decreased liver collagen detected in the present study.     

Nutritional status of the Indian population

High prevalence of low birth weight, high morbidity and mortality in children and poor maternal nutrition of the mother continue to be major nutritional concerns in India. Although nationwide intervention programmes are in operation over two decades, the situation has not changed greatly. In addition, the Indian population is passing through a nutritional transition and is expected to witness higher prevalences of adult non-communicable diseases such as diabetes, hypertension and coronary heart disease according to the theory of ‘fetal origin of adult disease’. Clearly, there is a need for examining several issues of nutritional significance for effective planning of interventions. In particular, maternal nutrition and fetal growth relationship, long term effects of early life undernutrition, interactions of prenatal nutritional experiences and postnatal undernutrition are some of the major issues that have been discussed in the present paper with the help of prospective data from various community nutrition studies carried out in the department.     

Ethnic expansions and between-group differences in children's health: a case study from the Rukwa Valley, Tanzania

The Sukuma ethnic group appears to be expanding across Tanzania at a rate far greater than other ethnic groups in the area. In this paper, the household-level dynamics that may be fueling this expansion are explored by comparing measures of infant mortality and child health with another Tanzanian ethnic group, the Pimbwe. Consistent with expectations, the Sukuma appear to have comparable levels of fertility but lower child mortality. As predicted, compared to the Pimbwe, Sukuma children are also heavier and taller for their age, suggesting better nutritional status. Four hypotheses about why the Sukuma are so successful in this area are addressed. Surprisingly, the results show that household food security and wealth are not related to children's nutritional status, nor can maternal effects account for the observed health differences. Several lines of evidence suggest that different patterns of infant feeding practices may underlie the differences in children's nutritional status.     

The hypothalamic POMC mRNA expression is upregulated in prenatally undernourished male rat offspring under high-fat diet

Epidemiological studies demonstrated that adverse environmental factors leading to intrauterine growth retardation (IUGR) and low birth weight may predispose individuals to increased risk of metabolic syndrome. In rats, we previously demonstrated that adult male IUGR offspring from prenatal 70% food-restricted dams throughout gestation (FR30) were predisposed to energy balance dysfunctions such as impaired glucose intolerance, hyperleptinemia, hyperphagia and adiposity. We investigated whether postweaning moderate high-fat (HF) diet would amplify the phenotype focusing on the hypothalamus gene expression profile. Prenatally undernourished rat offspring were HF-fed from weaning until adulthood while body weight and food intake were measured. Tissue weights, glucose tolerance and plasma endocrine parameters levels were determined in 4-month-old rats. Hypothalamic gene expression profiling of adult FR30 rat was performed using Illumina microarray analysis and the RatRef-12 Expression BeadChip that contains 21,792 rat genes. Under HF diet, contrary to C animals, FR30 rats displayed increased body weight. However, most of the endocrine disorders observed in chow diet-fed adult FR30 were alleviated. We also observed very few gene expression changes in hypothalamus of FR30 rat. Amongst factors involved in hypothalamic energy homeostasis programming system, only the POMC and transthyretin mRNA expression levels were preferentially increased under HF diet. Both elevated gene expression levels may be seen as adaptive mechanisms counteracting against deleterious effects of HF feeding in FR30 animals. This study shows that the POMC gene expression is a key target of long-term developmental programming in prenatally undernourished male rat offspring, specifically within an obesogenic environment.     

Low pasture allowance until late gestation in ewes: behavioural and physiological changes in ewes and lambs from lambing to weaning

Low pasture allowance during gestation affects ewes’ BW at parturition, the bond with their lamb, lamb development, and thus also may affect their responses to weaning. The objectives were to determine if native pasture allowance from before conception until late pregnancy affects ewe–lamb behaviours at lambing, ewes’ milk yield, lambs’ BW, and the behavioural and physiological changes of ewes and lambs at weaning. From 23 days before conception until 122 days of pregnancy, 24 ewes grazed on two different native pasture allowances: high (10 to 12 kg of dry matter (DM)/100 kg of BW per day; HPA treatment; n=12) or low (5 to 8 kg of DM/100 kg of BW per day; LPA treatment; n=12). Thereafter, all ewes grazed on Festuca arundinacea and received rice bran and crude glycerine. Ewes’ body condition score (BCS) and BW were recorded during pregnancy and postpartum periods. Milk yield was determined on days 32, 41 and 54 after lambing. Lambs’ BW was recorded from birth until 72 days after lambing. Latency from parturition until the ewe licked her lamb, maternal behaviour score (a test that evaluates maternal attachment to the lamb) and latency for lamb to stand up and suckle were determined. The behaviour of the lambs and ewes was recorded before and after weaning (at 65 days). The ewes’ serum total protein, albumin and globulin concentrations were measured before and after weaning. The HPA ewes presented greater BW (P<0.005) and BCS (P<0.005) than the LPA ewes during pregnancy and postpartum (P<0.04), and had a greater milk yield than the LPA ewes (P<0.03). Treatments did not influence any behaviour at lambing, lambs’ BW, neither the ewes’ behavioural and physiological changes at weaning. HPA lambs paced and vocalized more than LPA lambs (P<0.0001). The variation of albumin concentration before and after weaning was greater in the HPA lambs than in the LPA lambs (P<0.0001). In conclusion, although ewes’ BW, BCS and milk production were affected by pasture allowance until late pregnancy, this did not affect the behaviours that lead to the establishment of the mother–young bond, nor the ewes’ behavioural responses at weaning. Lambs reared by ewes that grazed on low pasture allowance during pregnancy presented fewer behavioural changes and a lower decrease of albumin concentration after weaning. Lambs’ BW was not affected by the feeding received by their mothers.     

Effect of undernutrition on GMP-PNP binding and adenylate cyclase activity from rat brain

1. Undernutrition is an insult that affects brain development and functioning. Considering that signaling through metabotropic receptors/G proteins is critical for normal synaptic transmission and contributes to CNS development and synaptic plasticity, the present study investigated the effects of pre- and postnatal protein deprivation (diet: 8% protein; normonourished group: 25% protein) on brain signal transduction by G proteins.2. Undernutrition decreased the [³H] GMP-PNP binding to G proteins and AC activity, in neural plasma synaptic membranes of 21- and 75-day-old rats. This effect was less pronounced or even absent in old rats.3. Ontogenetically, the dietary treatment effect might be interpreted as a retarded development associated with protein malnutrition.