EFFECT OF EXERCISE DURING PREGNANCY AND DAM AGE ON MATERNAL BLOOD-CHEMISTRY AND FETAL GROWTH

In order to determine the effect of maternal exercise on maternal nutritional status and fetal growth, young (Y = 45-50 days old) Wistar rats were divided into 4 groups of 5 to 8 animals: control pregnant (CP), control non-pregnant (CNP), exercise-trained (swimming 1 h/day, 5 days/week, for 19 days) pregnant (TP) and exercise-trained non-pregnant (TNP). Four equivalent groups of adult rats (A - 90-100 days old) were also formed. Serum glucose, total protein, albumin, hematocrit and liver glycogen were determined in female rats and pups. There were no statistical differences in serum glucose, total protein and albumin levels, litter size ot birth weight among exercise-trained animals, controls and their respective pups. Hematocrit was significantly lower in pups of exercise-trained young rats than in all other groups (YCP = 38.6 +/- 3.0; YTP = 32.6 +/- 2.1; ACP = 39.0 +/- 2.5; ATP = 39.2 +/- 2.9%). Liver glycogen levels were lower in pregnant than in non-pregnant rats but similar in exercise-trained and control rats of the same age and physiological status (YCNP = 4.1 +/- 0.2; YCP = 2.7 +/- 0.9; YTNP = 4.9 +/- 0.8; YTP = 2.7 +/-0.4; ACNP = 6.1 +/- 0.6; ACP = 3.1 +/- 0.8; ATNP = 6.6 +/- 0.8; ATP = 2.2 +/- 0.9 mg/100 mg). We conclude that pups of adult female rats are spared from the effects of this kind of exercise training during pregnancy. on the other hand, it appears that maternal adaptations to exercise training in young rats are able to preserve only some aspects of pup metabolism.

Constituintes sangüíneos de vacas das raças Nelore (Bos indicus) e Holandesa (Bos taurus) e de bubalinas (Bubalus bubalis) da raça Murrah durante a gestação, no dia do parto e no puerpério

Blood constituents of Nelore, Hosltein and buffalo cows were determined during pregnancy, at the time of calving and at post-partum. It was verified that. 1. The pregnancy and post-partum periods had no influence in the erythrocyte values, but at calving the red blood cell counts and hemoglobin levels of Holstein and buffalo cows were lower than for Nelore cattle; 2. leukocyte counts were similar among groups; 3. total protein levels of Nelore cows were lower than Holstein and buffalo. The albumin levels were rite lowest at rite time of calving compared to late pregnancy; 4. glicose levels were lower ill buffalo cows during pregnancy as compared with Holstein cows. The glicemia of Nelore cows was lower as compared to Holstein cow's irt late pregnancy; 5. urea and creatinine levels were higher in buffalo cows than cattle. The urea and creatinine levels were greater in buffalo cows with maximum values at the post-partum and at the parturition, respectively; 6. bilirrubin levels were higher in bovine than buffalo cows; 7. aspartate aminotransferase activity was greater in buffalo cows and increased at the time of calving; 8. alkaline phosphatase activity was increased during pregnancy and decreased after the time of calving; 9. gammnglutamyltransferase activity,vas the highest for buffalo cows after calving; IO. calcium levels were the highest for Holstein cows at the post-partum and the phosphorus levels were higher in buffalo cows, which had the highest magnesium levels at the parturation.

Tracing heme in a living cell: hemoglobin degradation and heme traffic in digest cells of the cattle tick Boophilus microplus

Heme is present in all cells, acting as a cofactor in essential metabolic pathways such as respiration and photosynthesis. Moreover, both heme and its degradation products, CO, iron and biliverdin, have been ascribed important signaling roles. However, limited knowledge is available on the intracellular pathways involved in the flux of heme between different cell compartments. The cattle tick Boophilus microplus ingests 100 times its own mass in blood. The digest cells of the midgut endocytose blood components and huge amounts of heme are released during hemoglobin digestion. Most of this heme is detoxified by accumulation into a specialized organelle, the hemosome.We followed the fate of hemoglobin and albumin in primary cultures of digest cells by incubation with hemoglobin and albumin labeled with rhodamine. Uptake of hemoglobin by digest cells was inhibited by unlabeled globin, suggesting the presence of receptor-mediated endocytosis. After endocytosis, hemoglobin was observed inside large digestive vesicles. Albumin was exclusively associated with a population of small acidic vesicles, and an excess of unlabeled albumin did not inhibit its uptake. The intracellular pathway of the heme moiety of hemoglobin was specifically monitored using Palladium-mesoporphyrin IX (Pd-mP) as a fluorescent heme analog. When pulse and chase experiments were performed using digest cells incubated with Pd-mP bound to globin (Pd-mP-globin), strong yellow fluorescence was found in large digestive vesicles 4 h after the pulse. By 8 h, the emission of Pd-mP was red-shifted and more evident in the cytoplasm, and at 12 h most of the fluorescence was concentrated inside the hemosomes and had turned green. After 48 h, the Pd-mP signal was exclusively found in hemosomes. In methanol, Pd-mP showed maximal emission at 550 nm, exhibiting a red-shift to 665 nm when bound to proteins in vitro.The red emission in the cytosol and at the boundary of hemosomes suggests the presence of heme-binding proteins, probably involved in transport of heme to the hemosome. The existence of an intracellular heme shuttle from the digestive vesicle to the hemosome acting as a detoxification mechanism should be regarded as a major adaptation of ticks to a blood-feeding way of life. To our knowledge, this is the first direct observation of intracellular transport of heme in a living eukaryotic cell. A similar approach, using Pd-mP fluorescence, could be applied to study heme intracellular metabolism in other cell types.

BIOSENSORS FOR GLUCOSE NEEDLE-SHAPED FOR IN-VIVO MONITORING

Different procedures for obtaining a needle biosensor for the determination of glucose to be inserted subcutaneously in vivo, have been compared. Platinum wires with a diameter of 75 mum, teflon-coated were inserted in hypodermic needles and fixed with a two-component epoxy resin. Using a dip-coating procedure, several layers were deposited on electrodes. The first coating was cellulose acetate, the second was immobilized glucose oxidase (GOD) mixed with bovine serum albumin (BSA) and glutaraldheyde, the third coating was a polyurethane coating obtained with commercially available products. A large number of electrodes have been tried and statistically evaluated but they seem to be affected by poor reproducibility evidenced by a large spreading in successive calibration curves. Then, the polyurethane coating has been replaced by a thin polycarbonate membrane salinized and fixed on the tip of the needle. Reproducible results were achieved and first results of in vivo measurements on rabbits are reported.