Corticosteroidogenesis in the hypertrophic adrenal gland produced by betamethasone 17, 21-dipropionate in the rat fetus

Betamethasone 17, 21-dipropionate (BMDP), a potent glucocorticoid, produces adrenal hypertrophy in the rat fetus. The present study was performed to investigate the possible alterations of corticosteroidogenesis due to endogeneous substrates or exogenous pregnenolone in the incubation of homogenates of fetal hypertrophic adrenals caused by BMDP given to pregnant rats at day 19 of pregnancy.The corticosteroidal products and those levels per mg homogenate in an incubate of the hypertrophic adrenal homogenate did not differ from those of a normal adrenal. No accumulations of abnormal precursors or intermediates were found in the incubates of the hypertrophic adrenals. It is concluded from these findings that no qualitative alterations in the pathway of corticosteroidogenesis occurred in the hypertrophic adrenal glands caused by BMDP in the rat fetus. When the calculation was done per adrenal gland, the content of corticosterone in the incubate of the homogenate of the hypertrophic adrenal was remarkably higher than that found in a normal gland. This finding was compatible with the significant increase of the plasma corticosterone concentration in the fetuses with the adrenal hypertrophy caused by BMDP.     

Incorporation of Serine-3-14C into Sphingolipid by Rat Liver Particulate

Four semi-synthetic and fourteen quassinoids were tested for their antifeedant and insecticidal activity against 3rd instar larvae of the diamondback moth (Plutella xylostella). In this quassinoid series, isobrucein-B was the most potent compound in both assays. Chemical conversion of the methoxy and/or methylenedioxy groups in the A and C rings to hydroxy groups among these quassinoids resulted in decreased activity.     

Characterization of a monoclonal antibody that induces the acrosome reaction of sea urchin sperm

A monoclonal antibody, J18/29, induces the acrosome reaction (AR) in spermatozoa of the sea urchin Strongylocentrotus purpuratus. J18/29 induces increases in both intracellular Ca2+ and intracellular pH similar to those occurring upon induction of the AR by the natural inducer, the fucose sulfate-rich glycoconjugate of egg jelly. Lowering the Ca2+ concentration or the pH of the seawater inhibits the J18/29-induced AR, as does treatment with Co2+, an inhibitor of Ca2+ channels. The J18/29-induced AR is also inhibited by verapamil, tetraethylammonium chloride, and elevated K+. All these treatments cause similar inhibition of the egg jelly-induced AR. J18/29 reacts with a group of membrane proteins ranging in molecular mass from 340 to 25 kD, as shown by immunoprecipitation of lysates of 125I-labeled sperm and Western blots. The most prominent reacting proteins are of molecular masses of 320, 240, 170, and 58 kD. The basis of the multiple reactivity appears to reside in the polypeptide chains of these proteins, as J18/29 binding is sensitive to protease digestion but resistant to periodate oxidation. There are approximately 570,000 sites per cell for J18/29 binding. J18/29 is the only reagent of known binding specificity that induces the AR; it identifies a subset of sperm membrane proteins whose individual characterization may lead to the isolation of the receptors involved in the triggering of the AR at fertilization.     

Phosphorylation and Inactivation of Brain Glycogen Synthase by a Multifunctional Calmodulin-Dependent Protein Kinase

Glycogen synthase was partially purified from canine brain to about 70% purity. The purified enzyme showed differences from the properties of the skeletal muscle enzyme with respect to molecular weights of the holoenzyme and subunit and phosphopeptide mapping. The multifunctional calmodulin-dependent protein kinase from the brain phosphorylated brain glycogen synthase with concomitant inactivation of the enzyme. Although about 1.3 mol of phosphate/mol subunit was maximally incorporated into glycogen synthase, 0.4 mol of phosphate/mol subunit was sufficient for the maximal inactivation of the enzyme. The results indicate that brain glycogen synthase is regulated in a calmodulin-dependent manner similarly to the skeletal muscle enzyme, but that the brain enzyme is different from the skeletal muscle enzyme.     

Infrageneric variation of the low molecular weight carbohydrate composition of the seeds of the genusVicia (Leguminosae)

The low molecular weight carbohydrate compositions of the seeds of 29 species ofVicia, namelyV. amoena, V. amurensis, V. bifolia, V. dumetorum, V. fauriei, V. japonica, V. nipponica, V. pisiformis, V. pseudo-orobus, V. sylvatica, V. unijuga, V. venosa, V. cassubica, V. orobus, V. cracca agg.,V. hirsuta, V. villosa agg.,V. tetrasperma,V. oroboides, V. sepium, V. cuspidata, V. grandiflora, V. lathyloides, V. sativa agg.,V. bithynica, V. faba, V. narbonensis, V. hybrida andV. lutea were determined by gas liquid chromatography. The carbohydrate compositions were found to be species-specific. Principal component analysis of the carbohydrate composition data showed that these species can be divided into three groups. Although, as far as the examined species were concerned, these groups were not correlated with the known subgenera, significant correlation between the groups and the known sections was detected in the subgenusVicia. The carbohydrate composition character would be important to clarify the relationships among closely related taxa of the genusVicia.     

Origin of changes in electrical impedance during the growth and fermentation process of yeast in batch culture

The electrical impedance of the culture medium shows complex changes during the growth and fermentation process of yeast, and this prevents its possible application for the monitoring of certain yeast activities. Clarification of the mechanism of such changes is thus essential for practical use. As a first step toward this aim, the impedance, yeast concentration, and pH of a batch culture medium were measured using special cells with two compartments and also the usual type of cell with one compartment. In the special cells, the yeast was cultured in one compartment only. Conducting ions and nonconducting substances diffused through an intermediate porous membrane sandwiched between the two compartments. The impedances of the two compartments were measured simultaneously by the four-electrode method. The main mechanism responsible for increasing the impedance was the conducting ions produced by the yeast extract added as a nutrient to the culture broth by certain nonconducting substances during the process of growth. The increase in the yeast concentration was also a minor factor increasing the impedance. These increases surpassed the impedance decrease caused by the increase of H(+) ions produced by some accumulated acidic substances, and the impedance thus increased.     

Intragranular co-storage of neuropeptide Y and arginine vasopressin in the paraventricular magnocellular neurons of the rat hypothalamus

Summary Certain populations of arginine vasopressin (AVP) neurons in the magnocellular paraventricular nucleus became immunoreactive for neuropeptide Y (NPY) when rats were treated with colchicine or monosodium glutamate (MSG). The co-storage of these peptides was examined by empooying a post-embedding electron-microscopic immunohistochemistry technique using goldlabeled antibodies to the two peptides. In colchicinetreated rats, the neuronal perikarya contained numerous secretory granules showing co-storage of the two peptides. The cells of the MSG-treated rats were characterized by having well-developed Golgi bodies with the granular structures also co-storing the two peptides, although the secretory granules in the perikarya were rather fewer than in the colchicine-treated rats. It is concluded that the destruction of the arcuate nucleus by MSG-treatment may potentiate the synthesis of NPY in AVP neurons, the synthesis of which is latent in intact animals.