ABSTRACT
Peripheral blood lymphocytes from healthy human donors were cultured with biotin and concanavalin A (Con A) for varying periods up to 48 h. At the end of incubation, the percentages of total, active, and stable E-rosettes were determined. The percentage of total E-rosettes decreased significantly in the course of time in both cultures with biotin and Con A, but more slowly than in the control cultures. Biotin and Con A induced a significant increase in the number of high-affinity E-rosettes (aE-RFC and sE-RFC). Preincubation for 4 h in the presence of puromycin or actinomycin D inhibited biotin, and Con A stimulated E-rosette formation. These results suggest that the effect of biotin on the T lymphocytes might be due to stimulation of protein synthesis and, perhaps, new receptors for sheep red blood cells (SRBC).
Subject(s)
Biotin/pharmacology , Rosette Formation , T-Lymphocytes/drug effects , Concanavalin A/pharmacology , Erythrocytes/immunology , Humans , T-Lymphocytes/immunologySubject(s)
Cattle/anatomy & histology , Endometrium/anatomy & histology , Estrus , Exocrine Glands/cytology , Ovulation Induction/veterinary , Animals , Cloprostenol/pharmacology , Cytoplasmic Granules/ultrastructure , Endometrium/ultrastructure , Epithelium/ultrastructure , Exocrine Glands/ultrastructure , Female , Gonadotropins, Equine/pharmacology , Microscopy, Electron , Organoids/ultrastructure , PregnancyABSTRACT
Biotin-deficient rats show a slower growth rate and a reduction in thymus, intestinal lymph nodes and spleen weight. The effect is reversible. Biotin administration to normal rats (1 mg/rat/day) causes an increase in intestinal lymph nodes and spleen, while there is no effect on body and thymus weight. The amount of thymus and spleen DNA is lower for deficient than control rats. No difference was noticed between the levels of DNA from normal control and biotin-deficient rat lymph nodes, and between the levels of DNA from normal rats treated and untreated with biotin. The time-course of the specific radioactivity of DNA and the DNA turnover shows that biotin increases both the incorporation of labelling in DNA and DNA turnover rate.