Gonadal steroid hormone level in blood plasma and milk of primiparous and multiparous nonpregnant and pregnant buffaloes

Changes in the concentration of progesterone and estradiol-17beta were measured by radioimmunoassay in 11 primiparous and 17 multiparous buffaloes at estrus and daily post insemination and in 6 nonbred buffaloes at 6 hour intervals from 4 days before expected estrus to one day after estrus. Plasma progesterone concentration at estrus was 0.1 ng/ml which rose to a peak level of 3.47 ng/ml on day 17. It fluctuated around this level in those animals which conceived, but followed a declining trend in those which failed to do so and attained lowest values on the day of next estrus. Temporal changes of the hormone revealed that the occurrence of major decline varjed between 16 and 62 h before estrus. The average concentration in milk was about three to four times higher than in plasma. The concentration of estradiol-17beta about 23.50 pg/ml at estrus and fluctuated around 10 pg/ml in animals that returned to estrus with a peak around estrus. Temporal changes of hormone revealed that peak level occurred 8-17 h before estrus. The concentration of estradiol in pregnant animals fluctuated around 10 pg/ml. The concentration in milk was about 2-3 times higher than in plasma. There was no significant (P > 0.05) difference in the concentrations of progesterone and estradiol-17beta between primiparous and multiparous animals.     

Luteinizing hormone and oestradiol-17β in blood plasma and milk during the oestrous cycle and early pregnancy in Murrah buffaloes

Immunoreactive luteinizing hormone and oestradiol-17β were measured by radioimmunoassay in 28 Murrah buffaloes. The concentration peaked sharply in blood plasma (plasma) coincident with the onset of oestrus (range 0 to +6 h), whereas the oestradiol-17β concentration increased before the onset of oestrus (range ?8 to ?17 h). There were erratic fluctuations in the LH concentration in milk which did not correlate with the concentration in the plasma. However, the basal concentration of LH in milk was significantly higher (P < 0.01) than in plasma. The oestradiol-17β concentration in milk mimicked that in plasma and was significantly higher (P < 0.001) than in plasma. There was no significant difference (P > 0.05) of these hormones in primiparous and multiparous animals.     

Electric convulsive therapy (ECT) increases plasma and red blood cell haloperidol neuroleptic activities

In nine schizophrenic patients (five males and four females) on haloperidol treatment, plasma and red blood cell (RBC) haloperidol neuroleptic activities were measured before and after ECT by radioreceptor assay. Five patients randomly selected from these patients also served as controls on another occasion and neuroleptic activities in plasma and RBC were examined before and after the premedication only. All patients given ECT showed a considerable increase in plasma and RBC haloperidol neuroleptic activities after ECT (% increase in plasma neuroleptic activity, 28–409%; mean + SD, 136 ± 155%, P<0.005, Wilcoxon test; % increase in RBC neuroleptic activity, 11–121%; mean + SD, 59 ± 40%, P<0.005). However, no significant increase was observed for either plasma or RBC haloperidol neuroleptic activity, when patients were examined after premedication only. It was suggested that ECT induced a transient redistribution of haloperidol. It remains to be studied whether this phenomenon is causally related to the previous observation that the combination therapy of ECT and neuroleptics is more effective in the treatment of schizophrenia than ECT alone.     

Determination of butaperazine in plasma and red blood cells by fluorometry

A simple and sensitive fluorometric method is described for the determination of butaperazine in plasma and red blood cells. This method is specific for butaperazine and reproducible over a wide range of drug levels in the blood. The sensitivity of the method is 8 ng/ml of blood, but could be increased for determining much lower levels.     

Chromatin structure of the potential Z-forming sequence (dT-dG)n X (dC-dA)n. Evidence for an "alternating-B" conformation

The sequence (dT-dG)n X (dC-dA)n is the most abundant purine-pyrimidine dinucleotide repeat in eukaryotic genomes. This sequence and certain others that contain alternating purine-pyrimidine residues have been shown to adopt the left-handed, Z-DNA conformation in vitro when subjected to negative torsional stress or elevated ionic strengths. We have asked whether (dT-dG)n X (dC-dA)n tracts exist in topologically constrained Z-form structures in vivo by examining the chromatin organization of these sequences in cultured mouse cell nuclei. We find that these elements are quantitatively packaged into typical core particles which are embedded in canonical polynucleosomal arrays. In addition, these sequences neither flank nor reside within regions of chromatin that are preferentially sensitive to S1 nuclease. These characteristics suggest that these tracts do not exist predominantly in the Z-form in vivo. Furthermore, employing techniques that permit prominent hybridization to DNA fragments as short as 18 bases, we provide evidence that in vivo, most (dT-dG)n X (dC-dA)n elements instead adopt an "alternating-B" conformation on the nucleosomal surface.     

Purification and properties of poly(ADP-ribose) synthetase from mouse testicle

Poly(ADP-ribose) synthetase has been purified to apparent homogeneity from mouse testicle by a rapid and simple procedure using column chromatography on DNA-agarose and on Cibacron blue F₃G-A-Sephadex G-150. The purified enzyme absolutely requires DNA for activity, and half-maximal activation occurs at a DNA concentration of 25 μg/ml. The K_m for NAD and V at pH 8.0 and 25 °C are 47 μm and 1400 nmol/min/ mg, respectively. The molecular weight is 116,000 as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Amino acid analysis indicates that the mouse testicle enzyme is very similar to calf thymus enzyme, but there is a difference in the contents of several amino acid residues between the two enzymes. This difference appears to reflect species or tissue specificity of poly(ADP-ribose) synthetase.     

Tris(1-methylcytosine-N3)ammineplatinum(II) perchlorate monohydrate,a model for simultaneous binding of three nucleobases to a single metal ion

A Pt(II) complex containing three 1-methylcytosine ligands (C), [Pt(NH₃)C₃] (CIO₄)₂· H₂], has been prepared starting with cis-Pt(NH₃)₂Cl₂, and its crystal structure has been determined. The title compound represents a model of a hypothetical interaction of cis.Pt(II) with three biomolecules which proceeds via an intermediate monochloro complex, cis-[Pt(NH₃)₂CCl]Cl, and loss of ammonia from this compound. [Pt(NH₃)C₃](ClO₄)₂·H₂O crystallizes in space group P2₁/c (No. 14) with a = 15.296(3), b = 4.666(3), c = 14.025(2) Å, β = 122.61(1)° and has 4 formula units in the unit cell. Data were collected with use of a Syntex P2₁ diffractometer and MoKα radiation. The crystal structure was determined by standard methods and refined to R₁ = 0.043 and R₂ = 0.056 based on 2925 independent reflections. The compound contains the three 1-methylcytosine ligands bound through N(3) with the three ligands almost perpendicular to the Pt coordination plane. The two C ligands trans to each other have identical orientations with respect to the platinum square plane whereas the cytosine trans to NH₃ has the opposite orientation. Bond lengths and angles are normal.     

Effects of butyric acid on cell cycle regulation and induction of histone H1(0) in mouse cells and tissue culture. Inducibility of H1 (0)in the late S-G2 phase of the cell cycle

We have examined the regulation of the synthesis of histone H1(0) in cultured mammalian cells treated with butyric acid. Treatment of cells with the inducer results in the arrest of synthesis of DNA and the other histones, while increasing the synthesis of H1(0) by a factor of 11. The induction of H1(0) by butyric acid occurs in a pulse with a peak at six hours, followed by a decrease to negligible levels. This pulse-like induction appears to be due to the fact that the cells are inducible for H1(0) only in the late S or G2 phases of the cell cycle. This, coupled with the fact that butyric acid blocks cells in G1, results in the burst of H1(0) synthesis after addition of the inducer. The G1 block provoked by butyric acid does not appear to result from the accumulation of H1(0). Removal of butyric acid from G1-blocked cells resulted in the resumption of cellular proliferation without prior loss of H1(0), demonstrating that the presence of this histone is not sufficient to prevent cellular proliferation.     

Studies on prolactin 48: Isolation and properties of the hormone from horse pituitary glands

Isolation of prolactin from equine pituitary glands has been described. It has a potency of 42 IU/mg in the pigeon crop-sac test and consists of 199 amino acids. The hormone has only four half-cystine residues in contrast to other mammalian prolactins which have six residues. From NH₂-terminal sequence analysis and amino acid composition of cyanogen bromide fragments, the NH₂-terminal disulfide loop is missing in the equine prolactin molecule. Circular dichroism spectra indicate that the α-helical content of equine prolactin appears to be lower (50%) than that found in the ovine hormone (65%).     

Interaction between heparin and human pregnancy-associated plasma protein A (PAPP-A): a simple purification procedure

Human pregnancy-associated plasma protein A (PAPP-A) binds to heparin-Sepharose. This affinity chromatography preceded by molecular sieve chromatography provides a simple two-step purification procedure of PAPP-A from late pregnancy plasma. One hundred percent of the applied PAPP-A was recovered, with more than 40% being electrophoretically homogeneous after the two procedures. The remaining PAPP-A could be purified by negative affinity chromatography on anti-total human serum immobilized on agarose.     

NADH: (acceptor) oxidoreductase from bovine adrenal medulla chromaffin granules

The NADH:(acceptor) oxidoreductase from membranes of bovine adrenal medulla chromaffin granules has been purified by column chromatography. After solubilization of the membranes with emulphogen, a nonionic detergent, the enzyme was purified by dye-ligand chromatography and gel filtration. The oxidoreductase appeared essentially homogeneous on two gel electrophoretic systems. On polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate, the enzyme revealed a dimeric structure with a combined molecular weight of about 55,000. The enzyme eluted as a detergent-lipid-protein aggregate with a Stoke's radius of 43 Å on gel filtration columns in the presence of emulphogen. The amino acid composition of the oxidoreductase was found to be distinct from that of similar enzymes from other organelles. Topographical experiments indicated that the enzyme is a transmembrane protein.     

Comparison of detergent-solubilized and membrane-bound forms of kidney (Na + K)-ATPase

The detergent solubilization of dog kidney (Na + K)-ATPase has been investigated. The nonionic detergents, Brij 58, C₁₂E₈, and Lubrol WX were tested for their ability to produce active, soluble enzyme. Lubrol WX gave the best results. Enzyme so treated is found in the supernatant fraction after centrifugation at 100,000g for 1 h. It has the same or slightly greater specific activity, the same subunit composition as judged by SDS-gel electrophoresis, and very similar kinetic parameters with respect to sodium, potassium, ATP, pNPP, and ouabain as the membrane-bound enzyme. The Lubrol-treated enzyme is stable for at least 5 days at 4 °C. The phospholipid content of the Lubrol-treated enzyme is decreased, as might be expected, by about 50%. Limited tryptic proteolysis and fluorescence changes seen after modification with FITC indicate that the solubilized (Na + K)-ATPase undergoes the same conformational transitions as the membrane enzyme. Our results indicate that kidney enzyme solubilized as described here is nondenatured and fully active, and therefore a valuable preparation for spectroscopic and other approaches for study of this enzyme.     

Effect of adenosylhomocysteine and other analog thioethers on a prokaryotic tRNA (guanine-7)-methyltransferase

S-Adenosylhomocysteine (SAH), a potent inhibitor of methyltransferases, and several thioethers structurally related to SAH, have been tested as potential inhibitors of tRNA (guanine-7)-methyltransferase from Salmonella typhimurium. The tested compounds are l-, d-, dl-S-adenosylhomocysteine, S-adenosylcysteine, methylthioadenosine, butylthioadenosine, thioethanoladenosine, isobutylthioadenosine, S-inosylhomocysteine, and methylthioinosine. Among them the highest inhibitory activity has been shown by SAH (K_i = 8 μM), whereas butylthioadenosine, isobutylthioadenosine, and thioethanoladenosine are almost inactive as inhibitors. The other compounds inhibit the enzyme with K_i values ranging between 400 and 800 μm. From these data it is possible to evaluate the importance of the -NH₂ and -COOH groups of the substrate in the binding to the enzyme molecule, as well as other features such as the chirality at the α-carbon atom and the length of the hydrocarbon chain connecting the -NH₂ and -COOH groups to the aromatic ring of adenosine. The aminic group of the adenosine is also critical, because S-inosylhornocysteine and methylthioinosine are poorer inhibitors in comparison with SAH and methylthioadenosine.     

Spectroscopic and magnetic properties of a novel pyrazine-bridged copper(II) chain: [Cu(terpy)(pyz.)](ClO4)2

The [Cu(Terpy)(pyz.)](ClO₄)₂ complex (were Terpy = 2,2′:6′,2′'-terpyridine and pyz. = pyrazine) was synthesized and characterized by means of spectral and magnetic properties. UV-visible and EPR spectra indicate a square pyramidal coordination for the copper(II) ion. Magnetic susceptibility measurements, reported in the temperature range 2–125 K, are analyzed in terms of regular and alternating Heisenberg-chain models giving 2J = ?4.4 K, g = 2.19 (regular chain) and 2J = ?5.6 K, 2J′ = ?1.7 K, g = 2.15 (alternating chain). The better agreement obtained with the alternating-chain model allows us to propose a dimerized zig-zag chain structure with the pyz. ligand bridging the copper(II) ions.     

The synthesis of 8-(6-aminohexyl)-amino-GMP and its applications as a general ligand in affinity chromatography.

The steady-state kinetic behaviors of the five rabbit adrenal norepinephrine N-methyl transferase isozymes have been compared with particular reference to substrate inhibition patterns. Four distinct substrate inhibition patterns were observed. The E-1 isozyme was not subject to inhibition by either substrate, while the E-2 isozyme was inhibited by both substrates. The E-3 and E-4 isozymes were inhibited by norepinephrine only, while E-5 is inhibited only by S-adenosylmethionine. The substrate inhibition constants were sufficiently small in relation to the Michaelis constants to make substrate inhibition an important factor in regulation of activities of the isozymes.     

Fecundity and reproductive ecology of a natural population of Actinia equina L. (Cnidaria: Anthozoa)

Results are given of sampling Actinia populations monthly for two years, recording colour and weight of adults and weight and number of young in each adult. An anemone has a lower probability of bearing young if exposed on the rock than if one of a group in a pool, and anemones seem to migrate in and out of pools at different times of the year. In the light of these observations the hypothesis that at least some planulae leave their parent and enter another anemone is considered.     

How does limited trypsinization influence the surface structure and binding of calcium to lipoprotein (a): a spin-labeling study

Enzyme kinetic studies are presented which demonstrate the activating effect of phosphate on the conversion of pyruvate to lactate by rabbit muscle lactate dehydrogenase. A simple method of active enzyme gel chromatography is used to preclude the possibility that this effect is due to redistribution of enzyme between tetrameric and dissociated states as the result of preferential binding of phosphate to the tetrameric enzymatic form. By analysis of the kinetic results in terms of an ordered two-substrate mechanism, the source of the activation is traced to enhancement of the strength of the enzyme-NADH interaction, primarily because of an increase in the rate constant for the formation of the binary enzyme-coenzyme complex. Preliminary estimates of the relevant equilibrium constants from the kinetic data indicate that the binding of phosphate to rabbit muscle lactate dehydrogenase leads to a two- to fourfold increase in the intrinsic association constant for the interaction between NADH and the enzyme under the conditions (pH 7.4, I = 0.15) used to study the activation phenomenon.     

Mechanism of action of benzo(a)pyrene and nicotine on hormone production by rat pituitary tumor cells

The effects of the cyclic aromatic hydrocarbon, benzo(a)pyrene (BaP) and that of the tobacco alkaloid, nicotine, on prolactin (PRL) and growth hormone (GH) synthesis by rat pituitary tumor cells in culture (GH cells) have been studied. Treatment of GH cells with nicotine (0.1–300 μg/ml) neither affected the growth, nor significantly altered the general pattern of hormone production in these cells. BaP at concentrations greater than 5 μg/ml irreversively inhibited the growth of these cells. The sublethal concentrations of BaP, which did not affect either 1) cell growth, or 2) amino acid transport or 3) total protein synthesis or degradation, did however inhibit specifically, hormone synthesis by these cells. More interestingly concentrations of nicotine which did not affect either cell growth or hormone synthesis, modulated both of these cellular processes in the presence of BaP. A concentration dependent stimulation of microsomal BaP monooxygenase activity was observed in nicotine or BaP treated cells. The effects of these drugs on stimulation of BaP monooxygenase activity seems to be additive. Nicotine also enhanced the association of radioactivity (presumably [³H] BaP metabolites) with DNA in [³H] BaP treated cells. It is concluded that nicotine by itself did not demonstrate any cytotoxic effect nor influence hormone synthesis in GH cells. However, this constituent of tobacco smoke stimulated BaP monooxygenase activity and the interaction of [³H] BaP metabolites with cellular DNA and also modulated BaP induced inhibition of hormone synthesis in GH cells.     

Spectroscopy and crystal structure of neodymium coordination compound with glycine: Nd2(Gly)6·(ClO4)6·9H2O

Neodymium complex compound with glycine: Nd₂(Gly)₆·(ClO₄₆·9H₂O was synthesized and obtained in the form of monocrystals. Absorption spectra recorded in the region of 8000–35 000 cm^-1 were measured along the crystallographic axes. Intensities of the f-f transitions were analysed on the basis of the Judd theory. The X-ray crystal structure determination of the complex is reported. Crystals are triclinic, space group P$\text{I}$, with a = 11.554(4) Å, b = 14.108(1) Å, c = 15.660(3) Å, α = 97.14(1)°, β = 102.82(2)°, γ = 105.28(1)°, V = 2355.25 ų Z = 2, M.W. = 1495.4, D_c = 2.129)(3) g cm^-3, D^m = 2.103(1) g cm^-3. The structure was solved by Patterson's method and successive Fourier syntheses giving the locations of all nonhydrogen atoms. The final R factor was 0.062 and R_w = 0.073 for 12869 reflections with |F_o| > 5σ|(F_o)|. The asymmetric unit consists of a dimeric formula unit. The coordination polyhedron of Nd atoms comprises seven oxygen atoms from glycine and two from water molecules. The neodymium-glycine bonding mode is compared with that of the calcium-glycine complex.     

Growth hormone receptors in lymphocytes of growth hormone-deficient children

Human growth hormone was injected intravenously into 18 growth hormone-deficient children and growth hormone binding sites in lymphocytes were investigated. Fresh circulating lymphocytes had a low initial value for the binding of growth hormone to solubilized receptors (3.45 +/- 1.46%) but after growth hormone injection, the binding rapidly increased to 14.8 +/- 4.2% at 2 1/2 h and 8.7 +/- 1.8% at 5 h. The sharp increase in binding is due to increase in the number of binding sites. Two control children who received chorionic gonadotropin had no change in lymphocyte growth hormone receptors. The methodological differences between the present study and previous attempts to identify human growth receptors in lymphocytes were (1) lymphocytes were separated and disrupted with Triton X-100 as quickly as possible (to avoid error from receptor leaking out of the cell) and (2) the receptors were assayed at 2 1/2 h after growth hormone administration (previous studies were 12-24 h later). One possible explanation for the data is that growth hormone receptor from liver is taken up by lymphocytes and rapidly released again, thus, contributing to the hormonal receptor economy in humans.