ABSTRACT
The sizes of lymphocyte populations in lymphoid organs of nicotinic acetylcholine receptor knockout and chimera (knockout/wild-type) mice were studied by flow cytometry. The absence of beta2 subunit decreased, while nicotine treatment increased B lymphocyte numbers in the bone marrow. In chimera mice, either beta2 or alpha7 subunits influenced lymphocyte populations in primary lymphoid organs, while in the spleen, only alpha7 receptors were critical. More annexin V-positive B cells were found in the bone marrow of knockout than wild-type animals. We conclude that nicotinic receptors are involved in regulating lymphocyte development and control the B lymphocyte survival.
Subject(s)
Cell Growth Processes/physiology , Lymphocytes/physiology , Receptors, Nicotinic/physiology , Animals , Antigens, CD/metabolism , Behavior, Animal , Bone Marrow Transplantation/methods , Cell Count/methods , Flow Cytometry/methods , Gene Expression Regulation, Developmental/genetics , Gene Expression Regulation, Developmental/physiology , Lymphocytes/classification , Male , Mice , Mice, Knockout , Nicotine/pharmacology , Nicotinic Agonists/pharmacology , Radiation Chimera/physiology , Receptors, Nicotinic/deficiency , Spleen/metabolism , Spleen/radiation effects , Thymic Factor, Circulating/metabolism , Thymic Factor, Circulating/radiation effects , alpha7 Nicotinic Acetylcholine ReceptorABSTRACT
Irradiation of the epithelial cells from human thymus (cell line HTSC) by arsenid-gallium laser (0.89 nm, 1500 Hz) induces an enhancement of thymic hormone production. The concentration of alpha-1-thymosin was substantially increased on the days 1 and 5 in culture after irradiation. The increase of thymulin level in cultural supernatants was less pronounced and displayed after irradiation during 3-4 minutes. Local laser irradiation of thymus region of rats (5 minutes, 10 times) induce the increase of serum concentration of alpha-1-thymosin and the decrease of serum level of thymulin 2 days after irradiation.
Subject(s)
Lasers , Thymus Hormones/radiation effects , Animals , Cell Line , Cells, Cultured , Epithelium/metabolism , Epithelium/radiation effects , Gamma Rays , Humans , Rats , Thymalfasin , Thymic Factor, Circulating/analysis , Thymic Factor, Circulating/radiation effects , Thymosin/analogs & derivatives , Thymosin/blood , Thymosin/radiation effects , Thymus Hormones/biosynthesis , Time FactorsABSTRACT
Whole-body exposure of rats to X-rays (4, 6 and 8 Gy) and neutron radiation (1, 1.5 and 2 Gy) causes a dose-dependent inhibition of endocrine function of thymus and death of its lymphoid cells. Shielding of thymus somewhat reduces the degree and duration of inhibition of thymus hormone secretion.
