Effect of heparin on the activation of the anticoagulation system by alpha-thrombin

Heparin-regulated alpha-thrombin ability to activate the response of the anticoagulation system has been studied by the perfusion of sinocarotid area of rabbits with DIP-alpha-thrombin-heparin complex. In a series of experiments the area was perfused with 1.8 micron DIP-alpha-thrombin and significant changes in anticoagulation parameters have been registered in systemic circulation. During perfusion of sinocarotid area by DIP-alpha-thrombin-heparin complex (2 microns) no activation of anticoagulation system was noted. DIP-alpha-thrombin-heparin perfusates contained no endogenic heparin, unlike DIP-alpha-thrombin perfusates. This confirms the absence of anticoagulation system response to DIP-alpha-thrombin. Control perfusion by heparin alone in equimolar concentrations revealed no changes in anticoagulation system. It is assumed that heparin, blocking cation subcentre of the recognition centre for high molecular compounds in the enzyme molecule, prevents the response of anticoagulation system, disturbing the enzyme ability to bind to specific receptors of the vascular walls.     

Thrombosis prophylaxis using plasmin and its combination with alpha-adrenoreceptor antagonists]

Using two models of experimental thrombosis (arterio-venous shunt and Wessler's model) the effect of plasmin and its combination with alpha-adrenoreceptor antagonists on the formation of thrombus was studied on white rats. It was established that the efficacy of prophylactic of thrombosis by plasmin only was low: middle ball of thrombosis was 2.5-3.0. The combination of plasmin with alpha-adrenoblockers dihydroergotoxine or prazosin under these conditions is most efficient against the formation of thrombus (middle ball of thrombus in this case was 0.8-1.1). Prazosin under certain conditions have some advantages.     

Elemental distribution in striated muscle and the effects of hypertonicity: Electron probe analysis of cryo sections

A method of rapid freezing in supercooled Freon 22 (monochlorodifluoromethane) followed by cryoultramicrotomy is described and shown to yield ultrathin sections in which both the cellular ultrastructure and the distribution of diffusible ions across the cell membrane are preserved and intracellular compartmentalization of diffusabler ions can be quantitated. Quantitative electron probe analysis (Shuman, H., A.V. Somlyo, and A.P. Somlyo. 1976. Ultramicros. 1:317-339.) of freeze-dried ultrathin cryto sections was found to provide a valid measure of the composition of cells and cellular organelles and was used to determine the ionic composition of the in situ terminal cisternae of the sarcoplasmic reticulum (SR), the distribution of CI in skeletal muscle, and the effects of hypertonic solutions on the subcellular composition if striated muscle. There was no evidence of sequestered CI in the terminal cisternae of resting muscles, although calcium (66mmol/kg dry wt +/- 4.6 SE) was detected. The values of [C1](i) determined with small (50-100 nm) diameter probes over cytoplasm excluding organelles over nuclei or terminal cisternae were not significantly different. Mitochondria partially excluded C1, with a cytoplasmic/ mitochondrial Ci ratio of 2.4 +/- 0.88 SD. The elemental concentrations (mmol/kg dry wt +/- SD) of muscle fibers measured with 0.5-9-μm diameter electron probes in normal frog striated muscle were: P, 302 +/- 4.3; S, 189 +/- 2.9;C1, 24 +/- 1.1;K, 404 +/- 4.3, and Mg, 39 +/- 2.1. It is concluded that: (a) in normal muscle the "excess CI" measured with previous bulk chemical analyses and flux studies is not compartmentalized in the SR or in other cellular organelles, and (b) the cytoplasmic C1 in low [K](0) solutions exceeds that predicted by a passive electrochemical distribution. Hypertonic 2.2 X NaCl, 2.5 X sucrose, or 2.2 X Na isethionate produced: (a) swollen vacuoles, frequently paired, adjacent to the Z lines and containing significantly higher than cytoplasmic concentrations of Na and Cl or S (isethionate), but no detectable Ca, and (b) granules of Ca, Mg, and P = approximately (6 Ca + 1 Mg)/6P in the longitudinal SR. It is concluded that hypertonicity produces compartmentalized domains of extracellular solutes within the muscle fibers and translocates Ca into the longitudinal tubules.     

Inductive effect of the eye tissues of adult clawed toads on the gastrula ectoderm

The inducing influence of adult eye tissues on the early gastrula ectoderm was studied in vitro. Both retina and pigment epithelium induced in the early gastrula ectoderm similar spectra of cell types, including nervous tissue, retina, pigment epithelium, lentoids, ectomesenchyme, and melanophores. It is suggested that the correspondence of these cell types with those arising at a spontaneous transdifferentiation of the isolated retina and pigment epithelium cells in vitro or at the induction of the early gastrula ectoderma by archencephalic endomesoderm during the normal development can be accounted for by that in these eye cells molecular determinants appeared as a result of induction and maintaina the stability of their differentiation and their potencies to transdifferentiation in vitro being reproduced during the lifetime of these cells.     

Inactivation of blood plasma alpha 1-proteinase inhibitor as affected by 2 splenic thiol proteinases active in a neutral medium

It has been found that two active in neutral medium thiol proteinases from bovine spleen, cathepsin L and cathepsin H, bring about rapid and irreversible inactivation of alpha 1-proteinase inhibitor (alpha 1PI)--one of the major plasma inhibitors of serine proteinases. The activity of the enzymes studied did not change upon the interaction with alpha 1PI. With stoichiometric proteinase/inhibitor ratio, the inactivation of alpha 1PI under the effect of cathepsin L was instantaneous, while under the effect of cathepsin H it occurred within 30-60 min. The products of alpha 1PI inactivation had an inhibitory effect on the rate of its reaction with cathepsin L. alpha 1PI inactivation under the action of cathepsin L and cathepsin H was accompanied by the decrease in the molecular mass of the inhibitor from 54 kDA to 46 kDa. This was, probably, caused by the hydrolysis of the peptide bond formed by NH2 group of threonine. The 46 kDa fragment did not undergo further degradation. It did not bind to immobilized trypsin but retained antigenic properties. The results obtained show that the limited proteolysis is a mechanism of the inhibitor inactivation. It is suggested that under some conditions thiol proteinases, upon their release from the cell, participate in the control of effective alpha 1PI concentration.     

The dynamic morphofunctional state of the adrenals in irradiated recipients following bone marrow transplantation

The influence of syngenic bone marrow transplantation in the dose of 1.10(7) cell/ml upon the adrenal gland state of lethally irradiated recipients at various stages of posttransplantation period during 3 months has been studied at 150 linear F1 (CBA x C57B) male mice. Histological and histochemical studies conducted have shown the transplantation of native and cryopreserved bone marrow of the lethally irradiated recipients to result, depending upon observation time, in undulating change in adrenal gland weight, cortex thickness and lipid content in spongiocytes, which testifies to the certain dynamics of processes, occurring in recipients' adrenal gland.