Utilization of 14C-tyrosine in brain and peripheral tissues of developmentally protein malnourished rats

MILLER, M., J. P. LEAHY, F. McCONVILLE, P. J. MORGANE AND O. RESNICK. Utilization of ¹⁴C-tyrosine inbrain and peripheral tissues of developmentally protein malnourished rats. BRAIN RES. BULL. 3(6) 681–686, 1978.—Prior studies of developmentally protein malnourished rats have reported substantial changes in brain and peripheral utilization of ¹⁴C-leucine, ¹⁴C-phenylalanine, and ¹⁴C-tryptophan. In the present study rats born to dams fed a low protein diet (8% casein) compared to the offspring of control rats fed a normal diet (25% casein) showed few significant differences in the uptake and incorporation of ¹⁴C-tyrosine into brain and peripheral tissues from birth to age 21 days. At birth, the 8% casein pups exhibited significant decreases in brain and peripheral tissue incorporation of tracer only at short post-injection times (10 and 20 min), but not at longer intervals (90 and 180 min). During ontogenetic development (Days 5–21), the 8% casein rats showed significant increases in uptake of ¹⁴C-tyrosine into the brain and peripheral tissues on Day 11 and a significantly higher percent incorporation of tracer into brain protein on Day 21 as compared to the 25% casein rats. For the most part, there were no significant changes in incorporation of radioactivity in peripheral tissues for the 2 diet groups on these post-birth days. Overall, the data indicates that developmental protein malnutrition causes relatively fewer changes in brain and peripheral utilization of the semi-essential amino acid tyrosine than those observed in previous studies with essential amino acids.     

Ventricular system of the brain of the dolphin, Tursiops truncatus, with comparative anatomical observations and relations to brain specializations

A comparative and quantitative anatomical study of the cerebral ventricular system of the dolphin, Tursiops truncatus, and six other mammalian species, including man, has been made in the course of extensive neuroanatomical investigations of the dolphin. Several techniques have been used in these studies to confirm the morphological arrangement and contours of the ventricles. Casts of the ventricles were produced by use of a variety of casting media and methods and their relative merits were investigated and described. Following injection of the brain with casting media, the brain was either totally removed by dissection or digestion or one hemisphere dissected away to reveal the relationships of the ventricular cast to the opposite cerebral hemisphere. Serial sections of the brains of three dolphins were cut in three cardinal planes, and from these a model of the entire ventricular system was reconstructed. Serial sections (Nissl and Loyez) were also used to identify structures closely related to the ventricular cavities. Our results show that components of the cerebral ventricular system of the dolphin reflect, to a considerable degree, many of the specialized features of that brain including brachycephaly, widened and foreshortened temporal lobes, large limbic lobe, hypodeveloped frontal region, absence of an occipital pole, and massive development of the tectal acoustic apparatus. The morphological characteristics of the ventricular system and the relationship of this system to brain areas is discussed with respect to possible functional and phylogenetic implications.     

Dynamic evolution of the adenine nucleotide translocase interactome during chemotherapy-induced apoptosis

The mitochondrial permeability transition pore complex (PTPC) is involved in the control of the mitochondrial membrane permeabilization during apoptosis, necrosis and autophagy. Indeed, the adenine nucleotide translocator (ANT) and the voltage-dependent anion channel (VDAC), two major components of PTPC, are the targets of a variety of proapoptotic inducers. Using co-immunoprecipitation and proteomic analysis, we identified some of the interacting partners of ANT in several normal tissues and human cancer cell lines. During chemotherapy-induced apoptosis, some of these interactions were constant (e.g. ANT-VDAC), whereas others changed strongly concomitantly with the dissipation of the mitochondrial transmembrane potential and until nuclear degradation occurred (e.g. Bax, Bcl-2, subunits of the respiratory chain, a subunit of the phosphatase PP2A, phospholipase PLC beta 4 and IP3 receptor). In addition, a glutathione-S-transferase (GST) interacts with ANT in normal tissue, in colon carcinoma cells and in vitro. This interaction is lost during apoptosis induction, suggesting that GST behaves as an endogenous repressor of PTPC and ANT pore opening. Thus, ANT is connected to mitochondrial proteins as well as to proteins from other organelles such as the endoplasmic reticulum forming a dynamic polyprotein complex. Changes within this ANT interactome coordinate the lethal response of cells to apoptosis induction.     

Cancer incidence in adults living in the vicinity of nuclear power plants in France,based on data from the French Network of Cancer Registries

Nuclear power plants (NPPs) release toxic emissions into the environment that may affect neighboring populations. This ecologic study was designed to investigate the possibility of an excess incidence of cancer in the vicinity of French NPPs by examining the incidence by municipality of 12 types of cancer in the population aged 15 years and older during the 1995–2011 period. Population exposure to pollution was estimated on the basis of distance from towns of residence to the NPP. Using regression models, we assessed the risk of cancer in a 20‐km zone around NPPs and observed an excess incidence of bladder cancer (Relative Risk (RR), 95% Credibility Interval (95% CI)) in men and women (RR_men = 1.08; 95% CI: 1.00, 1.17 and RR_women = 1.19; 95% CI: 1.02, 1.39). Women living within the 20‐km proximity areas had a significantly reduced risk of thyroid cancer (RR_women = 0.86; 95% CI: 0.77, 0.96). No excess risk of hematologic malignancies in either sex was seen. The higher than expected incidence of bladder cancer may be due to an excess incidence localized around the Flamanville NPP and the nearby La Hague nuclear waste treatment center, which is a source of chemical contaminants, many (including arsenic) of them known risk factors for bladder cancer. Differences in medical practices could explain the reduced risk of thyroid cancer. In this first study of adults living near NPPs in France, cancer incidence is significantly higher than in the references populations for one of the cancer types studied: bladder cancer.     

NRL and CRX Define Photoreceptor Identity and Reveal Subgroup-Specific Dependencies in Medulloblastoma

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Effects of pre- and early postnatal protein malnutrition on carcass composition and lipoprotein lipase activity in male rats

Little is known about the effects of pre- and early postnatal protein malnutrition on energy storage (e.g., carcass lipid) and expenditure (e.g., brown adipose tissue [BAT] thermogenesis) and their reversibility by nutritional rehabilitation. Therefore, the purpose of these experiments was to examine the permanence of prenatal and early postnatal protein malnutrition on energy balance in rats. Five weeks before mating and through gestation adult female rats were fed either a 25 or 8% casein diet (designated 25 or 8). Diet reversals were performed at birth and/or at weaning (designated B or W) and the pups were cross-fostered at birth. Thus, the groups were: 25-25B (controls), 8-25W (gestational and lactational protein malnutrition, 8-25B (gestational protein malnutrition), and 25-8B-25W (lactational protein malnutrition). Animals were weighed and sacrificed 200-250 days postpartum for carcass composition. Retroperitoneal white adipose tissue (RWAT) and interscapular BAT (IBAT) wet weights and lipoprotein lipase (LPL) activity were also measured in the 25-25B and 8-25W groups. Nutritional rehabilitation at birth (8-25B) resulted in normal body weights as adults. Lactational protein malnutrition (25-8B-25W) resulted in intermediate body weights to the controls (25-25W), which had the greatest weights, and the 8-25W group, which had the lowest weights. The 8-25W and 25-8B-25W rats also had significantly decreased carcass wet weight and total body water, fat and fat-free dry mass relative to the 25-25B and 8-25B groups, the latter two of which did not differ in their carcass composition.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of dietary protein on food and water intake in spontaneously hypertensive rats

We have been studying the development of hypertension in spontaneously hypertensive rats (SHR) fed a low protein diet. The effects of a low protein diet upon food and water intake were examined. Body weight gain, food and water intake were measured in three to twenty-three week-old SHR and Wistar Kyoto rats (WKY) fed diets containing 8%, 15% or 25% casein. Body weights of SHR and WKY fed an 8% casein diet were significantly lower at 23 weeks than rats on the higher protein diets, although both groups on the 8% diet consumed more food and water per g of body weight. In addition, SHR fed an 8% casein diet drank less water per gram of food than WKY or SHR fed 15% and 25% casein diets. These results indicate that changes in food and water intake, as a consequence of low protein diets, should be an additional consideration when examining the effects of dietary protein on the development of hypertension.