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PubMed1995

Role of progesterone in regulating the effect of estradiol on the secretion of thyrotropin-releasing hormone and dopamine into hypophysial portal blood in ovariectomized rats.

In this study, an investigation was undertaken regarding the effects of estradiol and progesterone on the secretion of thyrotropin-releasing hormone (TRH) and dopamine into hypophysial portal blood and on the concentrations of arterial plasma thyroid-stimulating hormone (TSH) and prolactin (PRL) in ovariectomized (Ovx) rats. Ovx rats were injected subcutaneously with either estradiol benzoate (25 micrograms/kg BW/day) or progesterone (10 or 50 mg/kg BW/day), or both estradiol benzoate and progesterone daily for 3 days. The control group was injected with sesame oil. The hypophysial portal blood was collected and mixed either with or without 2,3-dimercaptopropanol before extraction by methanol for measuring TRH or by perchloric acid for measuring dopamine. The femoral arterial blood was also collected. The concentrations of TRH in hypophysial portal plasma and that of PRL and TSH in femoral arterial plasma were measured by radioimmunoassay. The concentrations of catecholamine in portal plasma were measured by radioenzymatic assay. Concomitant estradiol benzoate and progesterone caused a dose-dependent increase in TRH concentration in portal plasma and that of PRL in arterial plasma in Ovx rats. Progesterone alone did not alter the concentration of portal plasma TRH and the concentration of arterial plasma PRL, but rather increased the concentrations of dopamine in the hypophysial portal plasma. These above results indicated that the increase in plasma PRL and TSH levels is associated with a rise in hypophysial portal plasma dopamine and TRH following injection of both progesterone and estradiol benzoate. We can conclude that stimulation of progesterone on the secretion of hypothalamic TRH is involved in the increase in plasma PRL following concomitant treatment of estradiol.

Animals↗
PubMedDate not supplied

Methylamines and polyols in kidney, urinary bladder, urine, liver, brain, and plasma. An analysis using 1H nuclear magnetic resonance spectroscopy.

Methylamines and polyols are known to behave as organic osmolytes in the adaptation of many cells to hyperosmolar conditions. Using 1H nuclear magnetic resonance spectroscopy to analyze perchloric acid extracts we have examined several tissues in the rat for the presence of these compounds. Methylamines such as glycerophosphorylcholine, choline and betaine were observed in the renal inner medulla, urinary bladder, urine, liver, brain, and plasma. Myoinositol was relatively abundant in the renal inner medulla and brain whereas sorbitol was detected only in the inner medulla. A variety of unidentified compounds was also detected in each tissue. Although these methylamines and polyols are known to respond to osmotic changes in the renal inner medulla, their responses in other tissues remain to be investigated.

Animals↗
PubMed1982

Fluorometry of selenium in human hair, urine and blood. A single-tube process for submicrogram determination of selenium.

This communication introduces a special lyophilization process for selenium determination by fluorometric methods. It permits a small sample volume, with several modifications including a single test tube process. Samples and standard are lyophilized first, then digested with nitric-perchloric acid mixture in a heated sand bath. Selenium is complexed with 2,3-diaminonaphthalene and extracted by n-hexane in the same test tube. The n-hexane layer is transferred to a cuvette and measured fluorometrically. Selenium concentration in healthy children from Long Island (aged 5-18 years) was: hair 0.765 +/- 0.114 microgram/g (n = 52), urine 28.65 +/- 8.27 micrograms/g creatinine (n = 66), and serum 95.4 +/- 14.4 ng/ml (n = 44). The current literature reflects an increase in the role of selenium in human nutrition. Thus, a simple but reliable method for determination of selenium in biological materials is needed in the clinical and research laboratory.

Adolescent↗
PubMed1977

Age changes of the pattern of F1 histone subfractions in rat liver and spleen chromatin.

The polyacrylamide gel electrophoresis of total histone extracted from young (3 months) and old (26-27 months) rat tissues does not show age-related differences in the pattern of the main five histones. However, when the lysine-rich F1 histone was extracted from chromatin separately by perchloric acid and purified by Biogel P-60 column chromatography from chromatin of rat liver and spleen, the polyacrylamide gel electrophoresis did show obvious age changes in the distribution of F1, F1o, and F1(00) subfractions. In liver chromatin the increase of rat-specific methionine-containing subfraction (F1met.) was also found.

Aging↗
PubMed1991

Highly effective extraction of carcinoembryonic antigen with phosphatidylinositol-specific phospholipase C.

Carcinoembryonic antigen (CEA) was highly effectively extracted with phosphatidylinositol-specific phospholipase C (PI-PLC) from various source materials. The yield of CEA was, in some cases, 20-30 times more than that obtained by the usual method with perchloric acid. Addition of 0.1-0.2 units of PI-PLC to 1 g tumor tissue and incubation at 37 degrees C for 1 h with continuous shaking seem to be practically sufficient for CEA extraction. A simple purification procedure for CEA after extraction with PI-PLC is proposed. The immunochemical properties of CEA thus obtained were found to be identical to those of CEA obtained by the usual method.

Adult↗
PubMed1979

Paul-Bunnell antigen in malignancies and rheumatoid arthritis.

By means of agglutination inhibition test, Paul-Bunnell (P-B) antigen was demonstrated in sera of patients with cancer (5%), lymphomas or leukemias (12.5%) and rheumatoid arthritis (RA) (1.4%) as well as in synovial fluids from RA patients (27%). In contrast, none of 124 normal human sera gave positive results. P-B antigen was also demonstrated in 3 of 12 perchloric acid extracts of cancer tissues and 2 of 11 saline extracts obtained at 100 degrees C from spleens of lymphoma-leukemia patients. Extracts of apparently normal tissues from 16 individuals gave negative results.

Antigens, Neoplasm↗
PubMed1985

Induction of antibodies in rats to a rat carcinoembryonic antigen.

In a previous communication, carcinoembryonic antigen (CEA) of rat, which is an analogue to human CEA, was demonstrated in gastrointestinal adenocarcinomas induced in inbred Fischer rats by injection of 1,2-dimethylhydrazine. Antibodies detectable by enzyme immunoassay were elicited in Fischer rats by immunization with a perchloric acid extract of the CEA-containing rat tumor, RCA-1, incorporated into Freund's complete adjuvant. Specificity studies showed that activity of the rat antisera could be virtually abolished by inhibition with the tumor extract used at a concentration of 25 micrograms/ml. Inhibition by newborn rat tissues required extract at a concentration of 250 micrograms/ml. Extracts of normal adult tissues did not inhibit at these concentrations, but did inhibit at a concentration of 2,500 micrograms/ml. The results showed that rat CEA, though present in low concentration in normal adult rat tissue, is capable of eliciting an immune response in rats.

Adenocarcinoma↗
PubMed1990

Isolation and characterization of rat carcinoembryonic antigen.

A rat tumor-associated antigen with properties similar to those of human carcinoembryonic antigen (CEA) has been detected with rabbit immune sera in extracts of transplantable rat colonic adenocarcinoma, RCA-1. This antigen, termed rat CEA, was also detectable by a monkey antihuman CEA serum and a rat monoclonal antibody to rat CEA. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of perchloric acid extracts of RCA-1 tumor, followed by immunoblotting with the above-mentioned anti-CEA reagents, revealed that rat CEA activity resided in components with a molecular weight of approximately 350 kD. The glycoprotein nature of these components was indicated by positive staining with periodic acid-Schiff. Sephadex G-200 chromatography, as well as Sepharose 4B chromatography with and without sodium dodecyl sulfate indicated that the 350-kD components existed in the extracts as molecular aggregates. The 350-kD material, which had been purified by an affinity column containing rat monoclonal antibodies to rat CEA, reacted with the rabbit and monkey anti-CEA sera. This provided strong evidence that serological activity of rat CEA was confined to the 350-kD components.

Animals↗
PubMed1988

Effects of moist-chamber and McCarey-Kaufman medium storage on the metabolic status of the cornea: a 31P-magnetic resonance analysis.

The rate of change in concentration of corneal phosphatic metabolites of cat corneas stored in moist chamber and McCarey-Kaufman (M-K) medium was determined in order to provide a basis for prediction of the corneal metabolic status at a given storage time. Perchloric acid corneal extracts were examined by phosphorus-31 magnetic resonance after storage at 4 degrees C of whole globes under moist-chamber conditions up to 48 h and of excised corneas in M-K medium up to 168 h. A significant decline in the corneal concentrations of ATP and a significant increase in inorganic phosphate occurred for both storage methods; however, depending on the metabolite, the rate of decline or increase was significantly greater for the moist-chamber-stored corneas. The phosphorylated sugars significantly increased and the glycerophosphodiesters significantly decreased in the moist-chamber-stored corneas, whereas both metabolites remained unchanged in the M-K-medium-stored corneas. There was no significant change in the dinucleotides and nucleoside diphospho-sugars during the time course for both storage methods. A threefold greater rate of decline was noted in the tissue energy modulus for the moist-chamber-stored corneas than for the M-K-medium-stored corneas (-0.0465 vs. -0.0121 modulus values/h). M-K medium was significantly more effective in the maintenance of high-energy phosphatic metabolites. The mathematical model for these rate determinations provides a basis for prediction of the corneal metabolic status at a given time in moist-chamber or M-K medium storage.

Adenosine Triphosphate↗
PubMed1990

Retinal cyclic GMP and AMP in rod-cone dysplasia: comparison of assays in fixed and unfixed retinal tissues.

The effects of 3 fixatives (formalin, Bouin's solution and glutaraldehyde-paraformaldehyde) on retinal cyclic AMP and GMP content were determined in canine eyes with a known abnormality of cyclic GMP metabolism. Cyclic nucleotides were measured by radioimmunoassay on perchloric acid (PCA)-precipitated retinal samples from fixed (left) and unfixed (right) eyes from nine 6-week-old rod-cone-dysplasia-affected Irish setter dogs. Cyclic AMP values were significantly lower for fixed retinas than for unfixed controls. Retinal cyclic GMP values were also lower from glutaraldehyde-paraformaldehyde-fixed samples, but were not different from control values for formalin- or Bouin's-fixed eyes, when the retina was PCA-precipitated promptly after fixation.

Animals↗
PubMed1991

Comparison of phosphate metabolites of the ocular humors.

Ocular humors (aqueous humor and vitreous body) were obtained from porcine eyes. Perchloric acid extracts were prepared from aqueous and vitreous aspirates, and phosphorus-31 nuclear magnetic resonance spectroscopy 31P-NMR performed. Resonance signals from four high-energy phosphate groups (phosphocreatine, adenosine tri- and diphosphate and the dinucleotides) and nine low-energy phosphate groups [dihydroxyacetone phosphate, hexose-6-phosphate, alpha-glycerophosphate, fructose-1,6-diphosphate, ethanolamine phosphate, choline phosphate, inorganic orthophosphate (Pi), glycerol-3-phosphorylethanolamine and glycerol-3-phosphorylcholine] were present in the aqueous humor and/or vitreous body. Vitreous body phosphates significantly elevated relative to that of the aqueous humor were: DHAP, Hex 6-P, alpha-GP, Fru 1,6-diP, CP, GPE, PCr, ATP, ADP, and the dinucleotides; only Pi was significantly lower. Six metabolic indices (monoesters, diesters, monoesters/diesters, monoesters/Pi, ATP/Pi, energy modulus) were determined; all vitreous body indices were significantly higher than those of the aqueous humor. In particular, the energy modulus, a measure of overall metabolic energy status, was higher in the vitreous body (0.121 +/- 0.047) than in the aqueous humor (0.05 +/- 0.021).

Animals↗
PubMed1996

Metabolic analysis of the rabbit cornea by proton nuclear magnetic resonance spectroscopy.

Perchloric acid extracts of the rabbit cornea were analyzed by high-resolution 1H NMR spectroscopy, including the two-dimensional shift-correlated (COSY) technique. Numerous metabolites including leucine/isoleucine, 3-hydroxybutyrate, valine, lactate, alanine, lysine, acetate, glutamate, creatine/phosphocreatine, taurine, glycine, inositol, glucose, tyrosine, phenylalanine, histidine, adenosine and formate have been simultaneously detected and identified in the NMR spectra. Concentrations of some of these were also determined. Of particular importance are the detection and identification of hypotaurine in the corneal tissue. Hypotaurine is a precursor of the synthesis of taurine and may act as an antioxidant. Moreover, the presence of choline, a precursor for acetylcholine, was established. This novel metabolite profile of the cornea obtained by high-resolution 1H NMR spectroscopy may be of value in the study of pathologic and toxic disorders.

Acetates↗
PubMed1996

Nuclear magnetic resonance studies of sugar metabolism in the human infant lens.

We investigated sugar metabolism in lenses isolated from infants with stage-5 retinopathy of prematurity (ROP). The lenses were incubated in 13C-labeled glucose (35.5 mM) or galactose (30 mM) for 24 h at 37.5 degrees C. Six to 8 lenses were pooled for each experiment. 13C-nuclear magnetic resonance spectroscopy was then performed on perchloric acid extracts of these lenses. Active aldose metabolism was indicated by the production of lactate. However, neither sorbitol nor dulcitol was detected. On the other hand, an experimental aldose reductase inhibitor, sorbinil, caused a decrease in the hexose monophosphate shunt activity suggesting an active polyol pathway. Both polyols therefore appeared to have been metabolized further. In addition, galactose metabolism was unique in that it not only involved a galactose-->glucose epimerization, but also a direct galactose-->ribose conversion, and a production of galactose-3-phosphate. Although it is possible that the ROP lenses have adapted to oxidative stress during the postnatal high-oxygen incubation for premature infants, we believe the observed sugar metabolism is representative of the developing human lens.

Aldehyde Reductase↗
PubMed1979

Effects of ischemia on tissue metabolites in red (slow) and white (fast) skeletal muscle of the chicken.

Brief periods of ischemia have been shown to produce marked reactive hyperemia in both red (slow) and white (fast) skeletal muscle. However, evidence is lacking for specific vasodilator metabolites which are rapidly produced in ischemic skeletal muscle. The present study examined the effects of 1 and 3 minutes of ischemia on creatine phosphate (CrP), adenine nucleotide metabolism, and anaerobic glycolysis in red anterior (ALD) and white posterior latissimus dorsi (PLD) muscles of the chicken. Tissue metabolite concentrations were determined from perchloric acid or trichloroacetic acid extracts using enzymatic assay or high pressure liquid chromatography. CrP or adenine nucleotides were not significantly altered in either muscle following 1 or 3 minutes of ischemia. However, adenosine increased by 611% in the ALD at 1 minute. Following 3 minutes of ischemia, adenosine concentrations were elevated by 439% and 201% in the ALD and PLD, respectively. The PLD showed the greatest increases in inosine and IMP. Inorganic phosphate increased by 67% and lactate increased by 142% in the ALD at 3 minutes. The PLD, which is reported to have a high anaerobic glycolytic capacity, showed no increase in lactate. These results support the hypothesis that adenosine may be a mediator of akeletal muscle reactive hyperemia following short periods of ischemia.

Adenosine↗
PubMed1989

Nuclear magnetic resonance study of regional metabolism after forebrain ischemia in rats.

Proton nuclear magnetic resonance (NMR) spectroscopy of perchloric acid tissue extracts has been used to follow serial postischemic changes in the levels of metabolites in the hippocampus, cerebellum, frontal lobes, and parietal/occipital lobes in a rat model of short-duration (10 minutes) forebrain ischemia. Shortly (10 minutes, 1 hour) after the ischemic insult, the levels of the amino acids alanine and gamma-aminobutyric acid are elevated and that of glutamate is depressed in all regions except the cerebellum. The levels of these species return to control values by 24 hours postischemia. No changes are observed in the levels of aspartate or N-acetylaspartate. Greatly elevated levels of acetate 10 minutes postischemia, particularly in the hippocampus, may be due in part to metabolic degradation of fatty acids released due to membrane breakdown. Elevated levels of lactate persist for up to 7 days postischemia, suggesting that normal mitochondrial functioning is not fully restored following the ischemic insult.

Acetates↗
PubMed1984

Proteinase inhibitory function in inflammatory lung disease. I. Acute bacterial pneumonia.

This study examines the bronchial alveolar lavage (BAL) samples from a group of patients with acute bacterial pneumonia (n = 13) and makes a comparison with a control group (n = 5). The proteinase inhibitory capacity was examined and found to be composed primarily of alpha 1-proteinase inhibitor (PI, alpha 1-antitrypsin) and, to a lesser extent, bronchial mucosal inhibitor. Although the average PI concentration was elevated approximately 5-fold in the pneumonia group, its inhibitory function against elastase was decreased 15-fold when compared with that in the control group. The pneumonia group showed an increased concentration of immunologically identified elastin-derived peptides. Some of the BAL fluid from patients with pneumonia showed elastolytic activity against amorphous insoluble lung elastin. The majority of the elastase appears to be of neutrophil origin. Bronchial mucosal inhibitor is shown to be a component of both normal and pneumonia BAL fluids by both immunologic quantitation and by its resistance to perchloric acid inactivation. Compared with those from control subjects, BAL samples from patients with acute bacterial pneumonia showed a decreased proteinase inhibitor function and both increased elastolytic activity and elastin-derived peptide concentration.

Acute Disease↗
PubMed1975

Dependence on dose of the acute effects of ethanol on liver metabolism in vivo.

The dose dependence of the acute effects of ethanol upon liver intermediary metabolism in vivo has been demonstrated in rats. Ethanol was given i.p. in doses of 0.69, 1.7, and 3.0 g/kg in equal volumes (20 ml/kg). The liver was freeze-clamped 120 min after injection, and multiple metabolites were measured in the perchloric acid extract of the tissue. Each group showed a significantly different pattern of metabolites, redox states, and phosphorylation potentials although the rate of ethanol disappearance, at least between the two highest dose groups, was not significantly different. The mitochondrial free [NAD+]/[NADH] ratios and the cytoplasmic free [NADP+]/[NADPH] ratio were paradoxically most reduced with the lowest dose of ethanol and became progressively more oxidized with increasing dose. Once established, the differences in these ratios between the groups tended to persist with time, relatively independent of the concentration of ethanol. In a somewhat different pattern, the phosphorylation potential ([ATP]/[ADP][P1]) remained at the control level in the low-dose group but was significantly elevated in the two higher-dose groups. The results, therefore, show distinct and complicated dose-dependent patterns of intermediary metabolism that cannot be explained completely by any one hypothesis but that imply significant dose-dependent effects of ethanol upon intermediary metabolism not directly related to NADH production.

Adenosine Triphosphate↗
PubMed1984

Energetics of sodium transport in the urinary bladder of the toad. Effect of aldosterone and sodium cyanide.

Experiments were designed to determine whether the stimulatory effect of aldosterone on sodium transport involves an increase in tissue ATP. Urinary bladders that were removed from toads presoaked in 0.6% saline for 48-72 h, mounted as sacs, and maintained in open circuit except for brief observation of short circuit current every 30 min responded to 100 nM aldosterone added to the serosal bath with an increase in short circuit current to 170% of control hemibladders, which plateaus at 2-3 h. Tissue (ATP)/(ADP) X (Pi) measured in perchloric acid extracts increased to a maximum of 208% of controls (P less than 0.001) and ATP increased to 116% of controls (P less than 0.01) at 180 min. The short circuit current response to aldosterone paralleled the increase in ATP and (ATP)/(ADP) X (Pi) measured at 75, 120, 180, and 240 min. In bladders clamped at -150 mV, the short circuit current response to aldosterone was greater: 280% of controls (P less than 0.001) and tissue (ATP)/(ADP) X (Pi) increased to 191% of controls (P less than 0.001). In continuously short circuited bladders and bladders clamped at +75 mV, the short circuit current response to aldosterone and the change in ATP, ADP, or Pi were markedly diminished. 100 microM amiloride added to mucosal bath decreased the short circuit current to zero and inhibited the short circuit current response to aldosterone, whereas tissue ATP increased to 141% (P less than 0.05). 100, 250, and 500 microM NaCN dropped the short circuit current to 59, 35, and 24% of control values, respectively. Concurrently, tissue ATP measured at 60 min after the addition of NaCN dropped to 79, 66, and 56% of control values, respectively, and tissue ATP/ADP dropped to 68, 50, and 40%, respectively. The data revealed significant correlation between the change in the rate of sodium transport produced by aldosterone or NaCN as measured by the short circuit current and the concentration of ATP (r = 0.96, P less than 0.001), as well as ATP/ADP (r = 0.95, P less than 0.001). In conclusion, these results support the view that the stimulatory effects of aldosterone on sodium transport involve an increase in ATP or (ATP)/(ADP) X (Pi).

Adenosine Diphosphate↗