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Abstract

Osteoinductive activity of the transitional epithelium in the urinary bladder increased by more than 3 times in aging guinea pigs. The count of inducible osteogenic precursors and their sensitivity to urinary bladder osteoinductive factor decreased by several times with age. Our experiments show that proliferation of some stromal precursors in the spleen requires not only platelet-derived factors, but also growth factors produced by urinary bladder transitional epithelium.

Effect of α-fetoprotein on the count of bone marrow and splenic stromal precursor cells and proliferation of their cultural descendants

“…The decrease in mouse splenic and bone marrow CFE-F after addition of α-FP directly into culture medium supports this hypothesis ( Table 2). At least two phenomena of stromal cell inhibition in cultures are described by the present time: one of them is observed after addition of mitogens or antibodies in vitro into splenic cell cultures or after addition of the corresponding conditioned media into splenic and bone marrow cultures (presumably, due to the effect of activated lymphocytes) [2,5,6]. These data are in line with the results obtained in studies of Profetal effect on cultured human peripheral blood ML.…”

“…It is known that in vivo injection of antigens causes a drastic elevation of CFC-F content in hemopoietic and lymphoid organs. For example, injection of S. typhimurium to mice in vivo causes a 10-fold increase in the content of CFC-F in the spleen as early as after 24 h; their content in the lymph nodes of guinea pigs increases more than 30-fold 24 h after injection of diphtheria toxoid, and immunization of mice with group A (type 5) streptococcus vaccine significantly increased (by 3.5 times) the content of CFC-F in the bone marrow [2][3][4][5][6]. However, this reaction of CFC-F pool to injection of α-FP can be due to the immunostimulating effect of this protein on the lymphoid tissue [7,[12][13][14].…”

“…Profetal in concentrations of 0.01-10.00 µg/ml activated ML by inducing lymphoid cell differentiation into cytotoxic lymphocytes and natural killer cells, increasing their activity and proliferative potential [7,12,13]. The other phenomenon of stromal cell inhibition in vitro is observed in rat and rabbit bone marrow and splenic cell cultures and seems to be due to macrophage activation in the presence of FCS [5,6]. Presumably, reduction of CFE-F in bone marrow and splenic cultures after addition of α-FP in vitro is due to activation of a certain category of non-stromal cells (lymphocytes or macrophages), present in the cultures by this fetal serum protein.…”

“…The data on the immunomodulatory effects of α-FP seemed to be the most interesting, because lymphocyte activation by antigen injection significantly modified the count of CFC-F in the spleen and bone marrow [2][3][4][5][6].…”

Platelet-Derived Growth Factor Requirement for Cultured Descendants of Rabbit Stromal Bone Marrow Precursors

“…Populations of stromal precursor cells (ClFU-F) from hemopoietic and lymphoid organs in different animal species are usually cloned in the presence of the same growth factors (GF) under the same culturing conditions. There are data on the existence of considerable interspecies differences in the sensitivity of ClFU-F to factors produced by non-stromal bone marrow cells coexisting with ClFU-F in cultures [2]. For instance, irradiated bone marrow cells from rabbits and guinea pigs (so-called feeder) after increasing cell density to a certain values suppress the formation of rabbit bone marrow ClFU-F colonies [2].…”