Fluctuations in levels of various gangliosides in the different tracts of the oviduct of the frog (Rana esculenta) during the reproductive cycle.

The ganglioside content and pattern have been followed in the different tracts (rectus, convoluted and uterine) of the frog oviduct during the reproductive cycle. The main variations we observed are: a) average higher levels of ganglioside sialic acid in the preovulatory phase, with two peaks in March and April for the convoluted and rectus tract, respectively, and a more homogenous behaviour for the uterine tract; in all three tracts of the oviduct a minimum coincident with the ovulation has been found; b) a balanced presence of sulfolipids and gangliosides in the uterine tract: in fact sulfolipids, whose variations have been determined in a previous work, are higher when gangliosides are lower and vice versa, maintaining nearly constant the total negative charge due to these glycolipids; c) an alternate fluctuation of monosialo- and disialo-gangliosides in the preovulatory phase and a net trend toward the increase of monosialo- and the decrease of disialogangliosides in the postovulatory phase; trisialo-gangliosides are in general less represented and show less marked variations; d) the presence of particular gangliosides in particular moments of the reproductive cycle: Fuc-GM1, a fucosylated ganglioside, is higher than the more represented GM1 during the ovulation, while GD1 alpha, a ganglioside with a sialic acid residue linked to GalNAc, is steadily present in all three tracts after ovulation.(ABSTRACT TRUNCATED AT 250 WORDS)

A rapid procedure for elimination of non-polar lipids hampering the usual polar lipid extraction and TLC separation.

A new and rapid method is proposed for extraction of non-polar lipids from tissues where they are present as abundant components which can interfere with the usual procedures of lipid extraction and TLC separation, and hamper, in particular, sulphatide visualization. A solvent more hydrophobic than chloroform, i.e.

Effects of low-power 632 nm radiation (HeNe laser) on a human cell line: influence on adenylnucleotides and cytoskeletal structures.

HeNe (632 nm) irradiation (5, 15 and 30 min) of an embryonal human cell line (EUE) was used to study the short-term effects on energy charge and the rapid, energy-dependent, remodelling processes of cytoskeletal and adhesion structures. The adenosine triphosphate (ATP) concentration, tested by luminometric and high performance liquid chromatography (HPLC) procedures, is constant after 15 and 30 min of HeNe treatment; the lower phosphorylated nucleotides, i.e.

Effects of glycosaminoglycans on U-937 leukemia cell proliferation and differentiation: structure-function relationship.

Glycosaminoglycans (heparins, dermatan sulfate, chondroitin sulfate) with different structures and physicochemical properties were evaluated for their capacity to influence proliferation and differentiation of U-937 cell line. The contrasting and specific effects of glycosaminoglycans (depending on their structures and properties) on a leukemia cell line could help explain the regulation of proliferative and/or differentiative processes of hematopoietic cells in order to clarify the control of development and differentiation of hematopoietic progenitor cells by bone marrow extracellular matrix. Heparin from beef intestinal mucosa, heparan sulfate from beef spleen, dermatan sulfate from beef intestinal mucosa, and chondroitin sulfate from bovine trachea were extracted and purified, and their purity, structures, and physicochemical properties were evaluated.

ATPase activity of melanosomes in liver pigment cells of Rana esculenta L.

Luminometric methods show that melanosomes in liver pigment cells of Rana esculenta L. have endogenous ATP and ATPase activity. The Km value of ATPase is 0.