Carbohydrate binding properties of complex-type oligosaccharides on immobilized Datura stramonium lectin

The carbohydrate binding specificity of Datura stramonium agglutinin was studied by analyzing the behavior of a variety of complex-type oligosaccharides on a D. Stramonium agglutinin-Sepharose column. Oligosaccharides which contain Gal beta 1----4GlcNAc-beta 1----4(Gal beta 1----GlcNAc beta 1----2)Man units are retarded in the column so long as the pentasaccharide unit is not substituted by other sugars. Oligosaccharides which contain unsubstituted Gal beta 1----4GlcNAc beta 1----6(Gal beta 1----4GlcNAc beta 1----2)Man groups and those in which there is at least one Gal beta 1----4GlcNAc repeating unit present on an outer chain bind to the column and are eluted with buffer containing N-acetylglucosamine oligomers. Binding was not affected by the inner core portion of complex oligosaccharides nor by the presence of a bisecting N-acetylglucosamine residue. With these principles in mind, the column can be used as an effective tool for the analysis of complex-type, asparagine-linked sugar chains.

Effect of exogenous dopamine on hypothalamic dopamine and norepinephrine concentrations in the neonatal brain in rats

Hypothalamic dopamine (DA) and norepinephrine (NE) concentrations were studied in the neonatal rats after acute (postnatal day 4) or chronic (postnatal days 1-10) DA injections (0.5 mg in 5% dextrose in 0.45% saline). Acute injection of DA twice on postnatal day 4 resulted in an increase of hypothalamic DA and NE concentrations 16 hr later. Chronic treatment with the DA (twice in a day) for 10 days resulted in a reduction of NE concentration in the hypothalamus. The results of these studies suggest that the amount and duration of exposure to exogenous DA during postnatal development may result in divergent effects on hypothalamic catecholamine concentration.

Fractionation of L-fucose-containing oligosaccharides on immobilized Aleuria aurantia lectin

The carbohydrate-binding specificity of Aleuria aurantia lectin was investigated by analyzing the behavior of a variety of fucose-containing oligosaccharides on an A. aurantia lectin-Sepharose column. Studies with complex-type oligosaccharides obtained from various glycoproteins by hydrazinolysis and their partial degradation fragments indicated that the presence of the alpha-fucosyl residue linked at the C-6 position of the proximal N-acetylglucosamine moiety is indispensable for binding to the lectin column. Binding was not affected by the structures of the outer chain moieties nor by the presence of the bisecting N-acetylglucosamine residue. These results indicated that A. aurantia lectin-Sepharose is useful for the group separation of mixtures of complex-type asparagine-linked sugar chains. Studies of glycosylated Bence Jones proteins indicated that this procedure is also applicable to intact glycoproteins. The behavior of oligosaccharides isolated from human milk and the urine of patients with fucosidosis indicated that the oligosaccharides with Fuc alpha 1----2Gal beta 1----4GlcNAc and Gal beta 1----4(Fuc alpha 1----3)GlcNAc groups interact with the lectin, but less strongly than complex-type sugar chains with a fucosylated core. Lacto-N-fucopentaitol II, which has a Gal beta 1----3(Fuc alpha 1----4)GlcNAc group, interacts less strongly than the above two groups with the matrix. Oligosaccharides with Fuc alpha 1----2Gal beta 1----3GlcNAc and Gal beta 1----4GlcNAc beta 1----3Gal beta 1----4(Fuc alpha 1----3)GlcNAc groups showed almost no interaction with the matrix.

Structures of the carbohydrate moieties of two monoclonal human lambda-type immunoglobulin light chains

Human Bence Jones proteins of lambda type, Wh and Nei, both of which belong to subgroup II, contain an asparagine-linked sugar chain. Their carbohydrate moieties were liberated as oligosaccharides by hydrazinolysis and labeled by reduction with NaB3H4 after N-acetylation. Structural studies of each oligosaccharide by sequential exoglycosidase digestion in combination with methylation analysis revealed that Wh lambda contains the mono- and disialylated oligosaccharides (Formula: see text). These oligosaccharides are different from the oligosaccharides found in another lambda-type Bence Jones protein, Sm lambda, by Chandrasekaran et al. [Chandrasekaran, E. V., Mendicino, A., Garver, F. A., & Mendicino, J. (1981) J. Biol. Chem. 256, 1549-1555] and Garver et al. [Garver, F. A., Chang, L. S., Kiefer, C. R., Mendicino, J., Chandrasekaran, E. V., Isobe, T., & Osserman, E. F. (1981) Eur. J. Biochem. 115, 643-652].

Purification of hamster melanoma tyrosinases and structural studies of their asparagine-linked sugar chains

In cultured melanotic melanoma, a marked decrease of pigmentation has been found to be induced by the addition of tunicamycin [Y. Mishima and G. Imokawa (1983) J. Invest. Dermatol. 81, 106-114]. Since it appears that this impaired pigmentation arises from the loss of asparagine-linked sugar chains serving as a signal for transport of tyrosinase from GERL (Golgi-associated endoplasmic reticulum of lysosomes) to premelanosomes, tyrosinases from the membrane fraction of Greene's hamster melanoma have been purified, and the structures of their sugar chains have been analyzed. Two kinds of tyrosinases were purified by Triton X-100 solubilization; DEAE-cellulose, Sephadex G-200, and DEAE-Sephadex column chromatography; and preparative polyacrylamide gel electrophoresis. The two tyrosinases were separated by polyacrylamide gel electrophoresis, and both corresponded to Mr 69,000. Their asparagine-linked sugar chains were released by hydrazinolysis and analyzed. The sugar chains of the two tyrosinases were identical except for the sialic acid contents. One mole of each tyrosinase contained 1 mol of high-mannose-type sugar chains and 3 mol of complex-type sugar chains. The former chain has Man3 approximately 5 X GlcNAc2 and the latter has Man3 X GlcNAc beta 1----4(+/- Fuc alpha 1----6)GlcNAc as their core structures. The complex-type sugar chains are composed of mono-, bi-, tri-, and tetraantennary sugar chains, with +/- Sia alpha 2----3Gal beta 1----4GlcNAc beta 1----as their outer chains.

Comparative study of the oligosaccharides released from baby hamster kidney cells and their polyoma transformant by hydrazinolysis

The asparagine-linked sugar chains of the membrane of baby hamster kidney cells and their polyoma transformant were quantitatively released as oligosaccharides by hydrazinolysis and labeled by NaB3H4 reduction. The radioactive oligosaccharides thus obtained were fractionated by paper electrophoresis. The neutral oligosaccharides of both cells were exclusively of high mannose type. The acidic oligosaccharides were bi-, tri-, and tetraantennary complex-type sugar chains with Man alpha 1----6 (Man alpha 1----3) Man beta 1----4 GlcNAc beta 1----4 (+/- Fuc alpha 1----6) GlcNAc as their cores and Gal beta 1----4 GlcNAc and various lengths of Gal beta 1----4 GlcNAc repeating chains in their outer-chain moieties. Prominent features of these acidic oligosaccharides are that all sialic acid residues were N-acetylneuraminic acid and were linked exclusively at C-3 of the nonreducing terminal galactose residues of the outer chains. Comparative study of oligosaccharides of the two cells by Bio-Gel P-4 column chromatography revealed that transformation of baby hamster kidney cells leads to a reduction in high mannose-type oligosaccharides and an increase in tetraantennary oligosaccharides. Increase of the outer chains linked at C-6 of the Man alpha 1----6 residue of the core is the cause of increase in the relative amount of highly branched oligosaccharides in the polyoma transformant.

[Suppression of puerperal lactation by metergoline]

Suppression of puerperal lactation by a potent serotonin antagonist, metergoline was studied in 33 puerperal women, i.e., abortion after sixteen weeks of gestation 6, premature labor 13, labor at term 13, and hydatiform mole 1. The drug was administered orally at a dose of 4 mg bid for 5 days to 26 subjects, starting within one week from delivery (group A). The remaining 7 subjects received 4 mg of metergoline bid for 7 days after more than 2 weeks from delivery (group B). Lactation was either rapidly suppressed or prevented in 22 out of the 26 subjects in group A and in all subjects in group B. After the therapy was stopped, rebound phenomena were observed in 4 subjects in group A and in 2 subjects in group B, but a further 5-7 days' treatment with metergoline produced satisfactory results. The mean plasma prolactin levels, studied in 10 subjects in group A at hourly intervals after the first metergoline dose, decreased significantly one hour later (p less than 0.05) and reached the nadir level, 19.9 +/- 2.6% of the mean basal value, 4 hours later. The daily plasma prolactin levels in 9 subjects were significantly lower than those of the control group during metergoline treatment (p less than 0.001). No side effects of metergoline medication were observed. Metergoline for a short course of administration is very effective in the suppression of puerperal lactation. In case of the suppression of lactation after the second week of puerperium, 10-14 days of metergoline treatment is recommended to avoid the rebound phenomena.

[Effects of bromocriptine and dopamine on pituitary hormone secretion in women]

The present study was designed to examine whether a dopamine agonist, bromocriptine (Brc) exerts similar effects as dopamine (DA) on the pituitary hormones secretion and also to investigate the interaction of these dopaminergic agents and a dopamine receptor antagonist, metoclopramide (MCP) on the DA receptors in the hypothalamic-pituitary axis. Thirty normal cycling women in the midfollicular phase volunteered for this study. Following the administration of Brc (2.5mg, orally) to 13 subjects, a partially significant fall in LH levels, but not in FSH levels, during 4h was observed. DA, infused at a rate of 5 micrograms/kg/min for 4h, induced a significant fall in LH levels between 1 and 4h, but in FSH levels only at 2.5h after the start of infusion in 9 subjects. The amplitude of the spontaneous pulsations of LH secretion which was observed in 8 control subjects, was diminished by DA, while the amplitude seemed to be augmented by Brc. The administration of MCP (10mg, i.v.) to all subjects at 3h during the 4h experimental period caused no observable change in LH and FSH levels. A significant and progressive decline in PRL levels was observed in both Brc-and DA-treated groups of subjects, and this PRL-lowering effect was markedly counteracted by MCP administration in DA-treated group, but not in Brc-treated group. Brc induced a widely varying but significant rise in GH levels, with which MCP did not appear to interfere, whereas DA failed to cause any significant changes in GH levels. These data suggest that Brc, in contrast with DA, seems to be able to increase the pulse amplitude, but not the basal level, of LH and to stimulate GH secretion. Brc is also regarded to be a potent and unique PRL inhibitor, because its PRL-lowering effect cannot be easily antagonized by MCP.

Urinary oligosaccharides of GM1-gangliosidosis. Structures of oligosaccharides excreted in the urine of type 1 but not in the urine of type 2 patients

Among the seven oligosaccharide fractions obtained by Bio-Gel P-4 column chromatography of urine of GM1-gangliosidosis Type 1 patients, three fractions (peaks V, VI, and VII) were completely missing in the urine of GM1-gangliosidosis Type 2 patients. Structural study of these oligosaccharide fractions by sequential exoglycosidase digestion in combination with methylation analysis and periodate oxidation has shown that peaks V, VI, and VII are mixtures of 16, 30, and 49 isomeric oligosaccharides. All these 95 oligosaccharides contain Gal beta 1 leads to 4GlcNAc beta 1 lead to 3 repeating structures in their outer chain moieties, indicating that the tissues of GM1-gangliosidosis Type 2 patients do contain beta-galactosidase activity which releases readily galactose residue from such repeating sugar chains.

Urinary oligosaccharides of GM1-gangliosidosis. Different excretion patterns of oligosaccharides in the urine of type 1 and type 2 subgroups

Oligosaccharide patterns obtained by gel filtration of the urine of GM1-gangliosidosis Type 1 patients are quite different from those of GM1-gangliosidosis Type 2. By studies of oligosaccharides in the four major peaks obtained from the Type 1 subgroup using sequential exoglycosidase digestion, methylation analysis, and periodate oxidation, the structures of 15 oligosaccharides: Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3Man beta 1 leads to 4GlcNAc, Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6Man beta 1 leads to 4GlcNAc, Man alpha 1 leads to 6(Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc, Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc, Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[Gal beta 1 leads to 4GlcNAc beta 1 leads to 4(Gal beta 1 leads to 4GlcNAc beta 1 leads to 2)Man alpha 1 leads to 3]Man beta 1 leads to 4GlcNAc, Gal beta 1 leads to 4GlcNAc beta 1 leads to 6(Gal beta 1 leads to 4GlcNAc beta 1 leads to 2)Man alpha 1 leads to 6(Gal beta 1 leads to 4Glc NAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc, Gal beta 1 leads to 4GlcNAc beta 1 leads to 6(Gal beta 1 leads to 4GlcNAc beta 1 leads to 2)Man alpha 1 leads to 6[Gal beta 1 leads to 4GlcNAc beta 1 leads to 4(Gal beta 1 leads to 4GlcNAc beta 1 leads to 2)Man alpha 1 leads to 3]Man beta 1 leads to 4GlcNAc, Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6, and 3(Gal beta 1 leads to 4GlcNAc beta 1 leads to 3Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3 and 6)Man beta 1 leads to 4GlcNAc, (formula see text) were elucidated. The amounts of total oligosaccharides excreted in the urine of the Type 2 subgroup were approximately one-tenth of those of Type 1. Moreover, the last eight oligosaccharides shown above, which have a Gal beta 1 leads to 4GlcNAc beta 1 leads to 3Gal beta 1 leads to 4GlcNAc beta 1 leads to outer chain, were completely missing in the urine of Type 2.

Effect of postovulatory treatment with a luteinizing hormone-releasing hormone analog on the plasma level of progesterone in women

(des-Gly-NH2(10),Pro-ethylamide9) luteinizing hormone-releasing hormone (LH-RH) (100 microgram) was administered subcutaneously once daily for 5 days during the postovulatory period in six women with regular menstrual cycles. Plasma levels of luteinizing hormone, follicle-stimulating hormone, estradiol, and progesterone were measured daily by radioimmunoassay from the ovulatory stage to menses. Suppression of plasma progesterone occurred during the treated luteal phase as compared with that of the control luteal phase. This finding suggests that repetitive, massive, endogenous luteinizing hormone or massive, exogenous, LH-RH itself during the early luteal phase of the cycle may induce functional luteolysis.