ABSTRACT
An attempt was made to find out the immunomodulatory role of thyroid hormone, tetraiodothyronine (T4), and its effect on in vitro mitogen induced blastogenesis. Human peripheral blood lymphocytes (PBL) were subjected to phytohaemagglutinin (PHA) concanavalin-A (Con. A) and pokeweed mitogen (PWM) in presence or absence of T4. Basal blastogenic response was significantly enhanced in dose related manner by T4. PHA and Con.A induced response was depressed significantly (r = -0.975 and r = -0.945) whereas less than 50 ng T4 in presence of PHA showed mild stimulation. On the other hand, PWM induced response in presence of T4 was enhanced significantly in dose related manner.
Subject(s)
Adult , Cell Division , Cells, Cultured , Concanavalin A/pharmacology , Humans , Lymphocyte Activation/drug effects , Mitogens/pharmacology , Phytohemagglutinins/pharmacology , Pokeweed Mitogens/pharmacology , Thyroxine/pharmacologyABSTRACT
Effect of long term administration of thyroid hormones and the removal of thyroid on humoral antibody response to S. typhi O antigen was studied in male albino rats of HM strain. Humoral antibody response to S. typhi O antigen was enhanced in animals pretreated with T3 or T4 at a dose of 10 micrograms daily for 15 days. Administration of thyroid hormones simultaneously along with antigen, resulted in suppression of antibody response. In thyroidectomized animals, the antibody titer to S. typhi O antigen was decreased; this decrease in antibody titer was restored to normal level following hormone supplementation. Thyroidectomy significantly depressed TLC as well. Total leucocyte count and absolute lymphocyte count were increased following hormone treatment. Present findings, thus show the lymphoproliferative response of thyroid hormones and their effect on antibody response suggesting the immunomodulatory role of thyroid hormones.
Subject(s)
Animals , Antibody Formation , Antigens, Bacterial/immunology , Male , O Antigens , Rats , Thyroid Hormones/physiologyABSTRACT
The effect of long term administration of thyroid hormones and its deprivation on delayed type hypersensitivity (DTH) reaction to 2-4 dinitrochlorobenzene (DNCB) was studied. Animals were either pre-treated with thyroid hormones (T3 or T4) for 15 days and then subjected to DNCB skin test or the animals received thyroid hormones and simultaneously subjected to DNCB skin test. In both the cases DTH reaction was found to be increased significantly. When DNCB skin test was performed in the thyroidectomized animals, DNCB skin reaction was significantly decreased and the reaction was restored to normal following supplementation of thyroid hormones to the thyroidectomized animals. TLC and ALC were increased significantly following hormone treatment and thyroidectomized animals. TLC hand, induced significant depression in the count which was restored by hormone administration to the thyroidectomized animals.