Biomaterial Database

Age-related RNA polymerase I activity in isolated nuclei of PHA stimulated human lymphocytes. 1986

D L Doggett, and B L Strehler, and T Makinodan

In order to extend to the immune system previous findings that there is an age-related loss of hybridizability of the genes for ribosomal RNA (rRNA) in several tissues of mice, dogs and humans, we have investigated the function of the genes for rRNA in human T lymphocytes. These cells were chosen because they show a substantial decline in function with age, greater than that of other components of the immune system. rRNA synthesis was determined by measuring tritiated-UTP incorporation into acid precipitable counts as a result of the action of RNA polymerase I in nuclei isolated from phytohemagglutinin (PHA) stimulated peripheral-blood lymphocytes from 24 young adult and old human donors. The number of PHA-responsive cells from each donor was determined by counting grains in autoradiographs after a pulse of tritiated-uridine had been administered to them. The aggregate PHA induced synthesis of rRNA in the cultures decreased as a function of the age of the donor. However, the number of PHA-responsive cells also dropped with age. When the data are normalized for the number of PHA-responsive cells in each culture, it appears that rRNA synthesis per PHA-responding cell does not significantly decline with age, even though there is a suggestion of a decrease after corrections are made. On the average, differences between individuals of the same age group were as great or greater than age-related differences.

UI	MeSH Term	Description	Entries
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D010835	Phytohemagglutinins	Mucoproteins isolated from the kidney bean (Phaseolus vulgaris); some of them are mitogenic to lymphocytes, others agglutinate all or certain types of erythrocytes or lymphocytes. They are used mainly in the study of immune mechanisms and in cell culture.	Kidney Bean Lectin,Kidney Bean Lectins,Lectins, Kidney Bean,Phaseolus vulgaris Lectin,Phaseolus vulgaris Lectins,Phytohemagglutinin,Hemagglutinins, Plant,Lectin, Kidney Bean,Lectin, Phaseolus vulgaris,Lectins, Phaseolus vulgaris,Plant Hemagglutinins
D002467	Cell Nucleus	Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)	Cell Nuclei,Nuclei, Cell,Nucleus, Cell
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D000368	Aged	A person 65 years of age or older. For a person older than 79 years, AGED, 80 AND OVER is available.	Elderly
D000375	Aging	The gradual irreversible changes in structure and function of an organism that occur as a result of the passage of time.	Senescence,Aging, Biological,Biological Aging
D012318	RNA Polymerase I	A DNA-dependent RNA polymerase present in bacterial, plant, and animal cells. The enzyme functions in the nucleolar structure and transcribes DNA into RNA. It has different requirements for cations and salts than RNA polymerase II and III and is not inhibited by alpha-amanitin.	DNA-Dependent RNA Polymerase I,RNA Polymerase A,DNA Dependent RNA Polymerase I,Polymerase A, RNA,Polymerase I, RNA
D012335	RNA, Ribosomal	The most abundant form of RNA. Together with proteins, it forms the ribosomes, playing a structural role and also a role in ribosomal binding of mRNA and tRNAs. Individual chains are conventionally designated by their sedimentation coefficients. In eukaryotes, four large chains exist, synthesized in the nucleolus and constituting about 50% of the ribosome. (Dorland, 28th ed)	Ribosomal RNA,15S RNA,RNA, 15S
D013601	T-Lymphocytes	Lymphocytes responsible for cell-mediated immunity. Two types have been identified - cytotoxic (T-LYMPHOCYTES, CYTOTOXIC) and helper T-lymphocytes (T-LYMPHOCYTES, HELPER-INDUCER). They are formed when lymphocytes circulate through the THYMUS GLAND and differentiate to thymocytes. When exposed to an antigen, they divide rapidly and produce large numbers of new T cells sensitized to that antigen.	T Cell,T Lymphocyte,T-Cells,Thymus-Dependent Lymphocytes,Cell, T,Cells, T,Lymphocyte, T,Lymphocyte, Thymus-Dependent,Lymphocytes, T,Lymphocytes, Thymus-Dependent,T Cells,T Lymphocytes,T-Cell,T-Lymphocyte,Thymus Dependent Lymphocytes,Thymus-Dependent Lymphocyte