Angiogenesis in developing rat brain: An in vivo and in vitro study

Brain capillary proliferation in postnatal rats was measured in vivo by [3H]thymidine autoradiography. Maximal capillary proliferation occurred between 5 and 9 postnatal days, and was 40 times greater than in the adult. To test the hypothesis that soluble angiogenesis factors play a role in this developmental vascularization of brain, we prepared extracts from the brains of 6-day-old rats at the peak of proliferative activity, and from adults when it was lowest. We assayed them using an in vitro growth system measuring [3H]thymidine incorporation into cultured brain capillary endothelial cells. Extracts prepared from either 6-day or adult rats and containing 150 [mu]g/ml protein caused more than a 4-fold stimulation of the endothelial cells, increasing to 8-fold at a concentration of 1500 [mu]g/ml. The presence of growth-promoting activity in brain extracts from both adult and immature rats suggests that soluble angiogenesis factors may be present in the brain throughout life, but are unavailable for stimulation of in vivo capillary growth unless released or activated by an appropriate stimulus.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25473/1/0000013.pd

Presence of a novel epithelial antigen on rat cerebellar cell lines as detected by a monoclonal antibody

We have derived a monoclonal antibody, MCAb 51, following immunization of BALB/c mice with a Rous sarcoma virus-transformed rat cerebellar cell line. When assayed by immunofluorescence on primary rat cerebellar cultures MCAb 51 recognizes only islands of cells with an epitheloid morphology. Double-label immunofluorescence experiments with MCAb 51 and antisera to tetanus toxin, glial fibrillary acidic protein, galactocerebroside and fibronectin reveal that these cells do not appear to be neurons, astrocytes, oligodendrocytes, or fibroblasts, respectively. In contrast, cells from kidney, liver, tongue and choroid plexus epithelium are positive for the antigen. Of 12 Rous sarcoma virus-transformed cell lines, in contrast to 2 out of 9 chemically transformed lines, 11 exhibit the MCAb 51 antigen. These findings demonstrate that MCAb 51 recognizes an epithelial cell surface marker. Possible explanations for the difference in the expression of the antigen on Rous sarcoma virus and chemically transformed neural lines are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25625/1/0000175.pd

Gastropods

82 p. : ill. ; 24 cm.Includes bibliographical references (p. 69-82)