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Two ecdysteroids were isolated from juveniles and adults as well as from eggs of the pycnogonid Pycnogonum litorale Ström and characterized by bioassay, thin layer chromatography, gas liquid chromatography, and high performance liquid chromatography. One of the hormones could be identified as 20-hydroxyecdysone whereas the other behaves in HPLC in a way that is similar to but not identical with ecdysone. This unidentified ecdysone-like hormone exceeded 20-hydroxyecdysone in all developmental stages (1.67:1 to 3:1). Determination of moulting hormone titers by a radioimmunoassay showed highest amounts of hormones in juvenile females (150 ng/mg tissue dry wt). The results are compared with those obtained from other arthropods and are discussed in view of the evolution of hormonal systems.

Increased plasma and tissue levels of vitamin E were found in spontaneously diabetic BB rats (D) as well as asymptomatic/diabetes-prone BB rats (AD) in comparison to levels in non-diabetic control rats (ND). Treatment of D rats with insulin for 30 days returned plasma and tissue values of vitamin E to control levels. The changes reported here could not be explained solely on the basis of variations in total lipid content of plasma. These data suggest the metabolism of vitamin E is altered in asymptomatic and spontaneously diabetic BB rats and this alteration returns to control values following insulin treatment. Furthermore, it might be speculated that these data indicate a relationship between vitamin E and insulin.

Vitamin E, ascorbic and dehydroascorbic acids were determined in plasma and selected tissues of rats fed for 2-3 months different diets varying in vitamin E content. The diets contained as low as 5 IU for group LE, a normal amount of 50 IU for group NE and as high as 250 IU of vitamin E for group HE. Small increases in total vitamin C were observed only in liver, kidney, spleen and plasma with increased dietary levels of vitamin E, however, this was not followed by a substantial increment in the ascorbate/dehydroascorbate ratio. These differences were only observed between diets LE and HE; there was no correlation between vitamin E and vitamin C levels in the tissue. These data suggest that the interactions that readily take place in vitro between these two vitamins do not occur in vivo, probably due to the complexity of natural membranes.

Oxygen consumption and concentration of noradrenaline (NA) in arterial plasma have been measured in warm-acclimated (WA) and in cold-acclimated (CA) rats during exposure to cold and in barbital-sedated WA or CA rats receiving intravenous infusions of NA at various doses at room temperature. In WA and in CA rats in the cold, NA in plasma increased rapidly from a resting level of 0.1 to 0.2 ng/ml at thermoneutrality to values 5 to 10 times greater at -19 degrees C. The increases were directly related to the degree of cold exposure and were maintained throughout exposure. In barbital-sedated WA or CA rats infused with NA the plasma levels of NA which stimulated calorigenesis were approximately 10 times greater than those resulting from overflow of NA into the blood during intense cold exposure and were in the range found by others to be effective in stimulating O2 consumption in isolated brown adipocytes.

Copper in blood plasma and liver and tissue reactions were compared for cattle injected with various amounts of copper salts of glycine or edetate. In young Holstein calves, initial concentrations of copper in blood plasma were normal (89 micrograms/dl). At 1 h postinjection, concentrations in plasma and the change were higher for the edetate group than for the glycinate group. Thereafter no differences of plasma copper occurred between forms of copper. Differences between concentrations of copper in plasma, especially for higher injections, occurred during the first 24 h but only occasionally thereafter. Hemolysis was severe during the 1st wk when 240 mg of copper edetate was administered but without mortality. Copper edetate caused less tissue irritation than equivalent copper from glycinate. Calves apparently mobilize injected copper rapidly from the subcutaneous site of injection, especially copper edetate, but concentrations in plasma are only increased temporarily. Copper is stored rapidly in the liver postinjection and probably serves to minimize toxic hemoconcentrations of copper.

Vitamin E (alpha- and gamma-tocopherol) and total lipid concentrations were determined in the serum of 451 healthy human male and female subjects ranging in age from 19 to 70 years. Mean serum alpha-tocopherol concentration (microgram/ml) was 8.82 +/- 2.84 (SD) and gamma-tocopherol concentration was 1.35 +/- 0.70. The concentration of alpha-tocopherol increased significantly with age, as well as with total lipid; gamma-tocopherol concentration remained unchanged with age. The data also indicated that subjects with higher serum alpha-tocopherol had lower gamma-tocopherol levels and vice versa for subjects with higher gamma levels. A close interrelationship and competition appeared to exist between these two vitamers.

Dopamine beta-hydroxylase (DBH) (3,4-dihydroxyphenylethylamine, ascorbate:oxygen oxidoreductase (beta-hydroxylating) (EC 1.14.17.1) activity in serum of blood obtained by decapitation of white rats at 19, 20, and 21 days in utero, immediately after birth, and postnatally to 70 days, was measured. Noradrenaline (NA) and DBH in plasma from undisturbed, cannulated, postweaning rats were also assayed. During the last few days in utero and the first 2 postnatal days serum DBH activity tripled and then remained elevated during the suckling period. Upon weaning, serum DBH activity declined at first precipitously and then more slowly, until the adult level was reached around 70 days of age. This postweaning decrease in DBH activity was also observed with the cannulated animals. In contrast, plasma NA levels remained low and constant throughout the postweaning period. In suckling rats treated with 6-hydroxydopamine from 2 to 12 days of age, serum DBH activity decreased to less than half its initial value by day 8. It is suggested that the observed changes in serum DBH activity in fetal and postnatal rats reflect ontogenetic changes in sympathetic nerve terminals and that they are probably not correlated with release of NA.

The pH optimum for rat serum dopamine beta-hydroxylase (DBH) (3,4-dihydroxyphenylethylamine, ascorbate:oxygen oxidoreductase (beta-hydroxylating)(EC 1.14.17.1) was 4.0 in acetate buffer; other requirements were as reported by others. DBH activity in serum of 20-day-old fetuses is slightly higher than in that of their mothers. Levels of the enzyme in blood a few hours after birth are almost five times greater than in the adult, remain high during the suckling period, then drop rapidly during the 4th week after birth to about three times the adult level, which is then slowly reached over the next few weeks. These fluctuations in serum DBH activity coincide with the period of intense development and maturation of the sympathetic nervous system. There was not significant effect of cold exposure on blood DBH activity when newborn, suckling, weanling or adult warm- and cold-acclimated rats were exposed to cold. Similarly, exposure to cold that elicited two- to three-fold increases in O2 consumption failed to increase DBH activity in thoracic duct lymph. Therefore serum and lymph DBH activities are not sensitive indices of sympathetic secretory activity in the intact rat.

A highly sensitive procedure for determining ascorbic acid (AA) and dehydroascorbic acid (DHAA) by high-performance liquid chromatography with electrochemical detection in biological fluids, tissues, and foods is described. AA is separated in a C18 reverse-phase column after extraction from the sample with metaphosphoric acid. An aliquot of 20 microliter of diluted extract is injected into the column for the estimation of AA. DHAA is indirectly estimated by converting it to AA after reduction with DL-homocysteine at pH 7.0-7.2 for 30 min at 25 degrees C. After dilution, a 20-microliter aliquot is injected into the column to obtain total vitamin C (AA + DHAA). The concentration of DHAA is calculated by subtraction. AA can be reproducibly quantified at concentrations as low as 50 pg/20 microliter of sample extract. The method described here used a specially designed mobile phase, gave greater stability and a noiseless baseline, and increased substantially the sensitivity and precision. The procedure is rapid, analysis being completed within 10 min after sample preparation, and has been successfully applied to biological fluids, tissues, and foods.

The effect of high dietary ascorbic acid intake on the homeostasis of ascorbic acid and on the metabolism of catecholamine was studied in rats. In order to eliminate changes in serum levels due to stress, blood was obtained without anesthesia through implanted cannulas. Rats with a high intake of ascorbic acid (20 g/kg diet, for 7-9 weeks) had significantly higher levels of ascorbic acid in serum (83%), liver (28%), kidney (47%) and superior cervical ganglia (43%). The values were slightly, but not significantly higher in adrenal gland, brain and interscapular brown adipose tissue. However, no significant differences were observed in the levels of noradrenalin, adrenalin and dopamine in any of the tissues analyzed. Dopamine beta-hydroxylase activity was also unchanged. There was thus no evidence of an effect of high dietary intakes of ascorbic acid on the metabolism of catecholamines in the intact rat.

The metabolism of alpha- and gamma-tocopherol was studied in three groups of rats that were fed a modified AIN-76 diet containing normal (NE, 0.2 g alpha-tocopherol/kg), high (HE, 1.0 g alpha-tocopherol/kg) or low (LE, less than 0.02 alpha-tocopherol/kg) vitamin E for 3 mo. After 1, 2 and 3 d of an oral dose of 20 mg of alpha-tocopherol, gamma-tocopherol or both, the levels of the two vitamers were measured in plasma and tissues and in some cases in isolated microsomal and mitochondrial fractions from liver. Twenty-four hours after an oral dose of 20 mg gamma-tocopherol the levels of alpha-tocopherol in plasma and tissues remained constant and higher levels of gamma-tocopherol were found in tissues in which low alpha-tocopherol levels could be found such as in the LE group. In spite of this, it was enabled to remain there, after 2 and 3 d gamma-tocopherol had decreased levels in all tissues. When given in combination with alpha-tocopherol, the levels of gamma-tocopherol were lower than when gamma-tocopherol was given alone. Microsomes and mitochondria from livers of LE group bound five and nine times more alpha-tocopherol than gamma-tocopherol in rats dosed with equal amount of alpha- or gamma-tocopherol, respectively. These data indicate that the mechanisms that regulate the metabolism of vitamin E are highly specific for alpha-tocopherol. Moreover, the relative amount of alpha-tocopherol determined the levels of gamma-tocopherol in tissues. However, the retention of gamma-tocopherol in tissues did not depend on the presence of alpha-tocopherol.(ABSTRACT TRUNCATED AT 250 WORDS)

Latex spheres with nominal diameters of 1.857, 2.02, 3.5, 5.2 and 9.69 mum were used to compare improvement in Coulter resolution gained (a) by a simple hydrodynamic focusing modification and (b) by Coulter edit and high resolution circuits. Since pulse size profiles of focused 9.69-mum spheres appeared quasimonodisperse [geometric SD (GSD) congruent to 0.016 congruent to (1 + Arithmetic SD/arithmetic mean)], unfocused profiles of these particles approximated the error function resulting from inhomogeneities in the electric and hydrodynamic sensing-zone fields. As expected, this field error function differed systematically with differences in orifice diameters (30, 50, 70 and 100 mum) and length to diameter ratios (0.75 or 1.2), the error being reduced slightly by the edit circuit and considerably by the high resolution circuit. Data on the 1.857- and 2.02-mum spheres (focused GSDs congruent to 1.06) and 3.5- and 5.2-mum spheres (focused GSDs congruent to 1.6) indicated that the field error affected closely similar particles similarly but its influence on the unfocused population means and variances differed in the GSD regions of 1.06 and 1.60.

Platelet count, platelet size, and circulating platelet biomass concentration estimates made with an erythrocyte-calibrated electronic sizing system on EDTA-anticoagulated blood samples gave population medians and 95% ranges for 145 asymptomatic Mediterranean and 200 healthy Northern European subjects. The Mediterraneans had lower platelet counts [161,000 (89,000-290,000)/mul compared with 219,000 (148,000-323,000)/mul] and higher arithmetic mean volumes [17.8 (10.8-29.2) cu mum compared with 12.4 (9.9-15.6) cu mum], while the individual lognormal platelet size distribution profiles were comparable [geomatric standard deviations of 1.78 (1.60-1.98) against 1.70 (1.54-1.88)]; and the platelet biomass concentrations, given by count per microliter times mean volume times 10- minus 7 and expressed as a volumetric percentage of whole blood, were almost identical [0.286% (0.216%-0.379%) against 0.272% (0.201%-0.367%)]. Mediterranean macrothrombocytopenia is, therefore, considered a benign morphologic variant that requires differentiation from thrombocytopenias in which the circulating platelet biomass concentration is decreased.

Dopamine-beta-hydroxylase (DBH) (EC 1.14.17.1) activity is present in the interscapular brown adipose tissue (IBAT) as early as 2 days of age in the white rat. The specific and the total activities of this enzyme, as well as those of cytochrome oxidase (COX) (EC 1.9.3.1) in IBAT increase up to at least 20 days of age. Daily administration of 6-hydroxydopamine (6-OHDA) between the second and the twelfth day after birth does not significantly alter IBAT weight gain relative to untreated controls, but the increase in protein content with age is reduced to about half the normal value at the end of the treatment. The treatment with 6-OHDA also results in a drastic lowering of DBH specific and total activities, and a much smaller rate of increase of COX specific and total activities with age in IBAT compared with controls. These results provide additional evidence for a previously proposed role of sympathetic nervous system activity in the development of the thermogenic potential of IBAT in the newborn rat.