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Biomedical subjects

G S Robins

Publications and source records attributed to G S Robins.

5 recordsLinked to original sources
PubMed2000

Kainic acid rapidly induces cyclooxygenase (COX)-2 in piglet cerebral cortex.

Ischemia/reperfusion (I/R) results in a robust induction of cyclooxygenase (COX)-2 in the newborn brain via unknown mechanisms, but glutamate release and activation of KA receptors may be involved. We examined effects of local KA (3-300 micromol/l for 10 min) treatment on cortical COX-2 expression in anesthetized piglets using a closed cranial window. Treated and corresponding control tissue samples were collected 0.5-10 h after treatment. COX-2 mRNA and protein levels were assessed using RNase protection assay and immunohistochemistry, respectively. KA elicited reproducible dose-dependent increases in cortical COX-2 mRNA unaffected by indomethacin or N(G)-nitro-L-arginine methyl ester pretreatment. COX-2 mRNA levels were elevated at 30 min, peaked at 2 h, but remained enhanced for up to 10 h after KA. Neuronal COX-2 immunoreactivity was also enhanced compared with the control side in all cortical layers 8h after KA. In summary, activation of KA receptors may be involved in the neuronal induction of COX-2 after I/R in the newborn.

Animals↗
PubMed1999

Endothelial nitric oxide synthase gene transfer enhances dilation of newborn piglet pulmonary arteries.

We determined the expression and functional correlate of in vitro transfection with a recombinant adenoviral vector encoding the gene for bovine endothelial nitric oxide synthase (AdCMVeNOS) or Escherichia coli beta-galactosidase (AdCMVLacZ) in pulmonary endothelial cells (EC), vascular smooth muscle cells (VSMC), and pulmonary arteries (PA) from newborn piglets. AdCMVeNOS and AdCMVeLacZ vectors, grown in 293-cell monolayers, were purified by double-cesium gradient ultracentrifugation. Cell cultures and PA were incubated with increasing vector titers for 30 or 60 min, followed by incubation in fresh medium for 18 h at 37 degrees C. LacZ expression was assessed by histochemical staining; eNOS expression was evaluated by Western blot analysis. Functional eNOS expression was determined by measurement of cGMP and quantification of the relaxation response to bradykinin (BK). In PA, LacZ transgene expression was preferentially localized to the adventitia and endothelium. Increased eNOS protein expression was observed in EC and VSMC transfected with AdCMVeNOS. Functional studies revealed increased cGMP abundance in cultured cells and enhanced relaxation to BK in AdCMVeNOS-transfected PA. These studies demonstrate that gene transfer with AdCMVeNOS results in functional expression and altered vasoactive responses in the neonatal pulmonary vasculature. Gene transfer with replication-deficient adenovirus vectors is a useful tool for the study of targeted genes in vascular biology.

Animals↗