Comparison of in vitro and in vivo cell cycle parameters of lymphoid cells in Pig spleens

Trepel

1979

Anat. Rec.

Lymphocyte production by mesenteric lymph nodes of normal young pigs was studied by intranodal injections of either tritiated thymidine or tritiated deoxycytidine as DNA precursors. One or two days after selective labeling of the mesenteric lymph nodes the relative and absolute number of lymphocytes derived from mesenteric lymph nodes were determined autoradiographically in the following organs: mesenteric, cervical and inguinal lymph nodes, spleen, thymus, bone marrow, Peyer's patches, tonsil, different regions of the gut, lung and liver. The overall cell production of mesenteric lymph nodes, as derived from the sum of all labeled cells one day after labeling, was estimated to be about 7 X 10(9) lymphocytes. Up to 40% of all newly formed lymphocytes had already left the lymph nodes within one day and were found in all organs studied. There was a preferential homing to the mucosa of the small intestine, but a considerable number migrated to the spleen and even to the thymus and bone marrow. In lymphoid organs all labeled cells were small and medium-sized lymphocytes one and two days after labeling. In cervical lymph nodes, spleen, tonsil and Peyer's patches the relative distribution to T and B cell areas was determined. There was an obvious preference of newly formed lymph node cells to home to T cell areas. The differences of labeling between thymidine or deoxycytidine were surprisingly low.

Selective labeling of mesenteric lymph nodes: Cell production and emigration ofnewly formed lymphocytes to other organs

Trepel

1979

Anat. Rec.

Comparison of lymphocyte production in lymphoid organs and their compartments using the metaphase-arrest technique

Fritz

1986

Cell Tissue Res.

Lymphocyte proliferation was studied in normal young anesthetized pigs by the metaphase-arrest technique using vincristine (VCR). In each animal biopsies were taken simultaneously from the thymus, mesenteric lymph nodes, spleen, palatine tonsil and Peyer's patches from the ileum and jejunum. After taking the first samples, 0.25 mg VCR/kg body weight was injected i.v. and then four more biopsies were excised for up to 3.5 h after VCR. Imprints of the lymphoid organs were evaluated as an overall index for each organ, and histological sections were used to determine the mitotic index in typical B- and T-lymphocyte areas in these organs. In follicles of mesenteric lymph nodes, tonsils and the two types of Peyer's patches a comparable increase in the mitotic index was found, 3.62% per hour. In the corona the increase was also comparable but much lower, 0.43% per hour and in the interfollicular area similarly 0.38% per hour. In the spleen the mitotic rate was 0.69% for the white pulp and 0.42% per hour for the red pulp. In the thymic cortex the mitotic index increased by 0.49% and in the medulla by a surprisingly high value of 0.32% per hour. The metaphase-arrest technique in larger animals enables a comparison of lymphocyte production among organs and their different compartments, and demonstrates the important contribution of peripheral lymphoid organs to the renewal of the lymphocyte pools.

Perfusion of isolated human spleens

Reinecke

1980

Blut

Twelve normal human spleens were perfused in vitro for 17 h at normothermia. The histological structure was well preserved. Splenic imprints showed a normal cellular pattern, mitoses, and labelled lymphoid cells after 3H-thymidine labelling. Metabolic parameters were comparable to in vivo data of human spleens. The perfusion system can preserve the structure and function of human spleens in vitro.