Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.48 (transcriptase)
 9,479 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The contribution of P2 receptors to vasoconstriction of mouse mesenteric arteries was determined using wild-type (WT) and P2X(1) receptor-deficient (KO) animals. alpha,beta-methylene ATP (alpha,beta-meATP) and ATP evoked transient inward currents and constrictions of WT mesenteric arteries. In contrast, alpha,beta-meATP (100 microM) and ATP (100 microM) failed to evoke responses in KO arteries from a range of vascular beds. Nerve stimulation (100 pulses at 10 Hz) evoked constrictions of mesenteric arteries. For WT arteries, the P2 receptor antagonist pyridoxalphosphate-6-azophenyl-2'-5'-disulfonate (PPADS) (30 microM) reduced the amplitude of response by approximately 50%; the residual constriction was abolished by prazosin (0.1 microM). In KO mice, vasoconstriction induced by nerve stimulation was reduced in amplitude by approximately 50%, unaffected by PPADS, but was abolished by prazosin. ADP (1 mM) (a P2Y(1), P2Y(12), and P2Y(13) receptor agonist) was ineffective. Because ATP had no effect on mesenteric artery tone from KO mice, this rules out the contribution of P2Y(2) receptors. The P2Y(4) receptor agonist ITP also failed to contract mesenteric arteries. However, UTP and UDP evoked sustained contractions of mesenteric arteries with similar potency (EC(50) approximately 10 microM). Complementary studies using reverse-transcriptase polymerase chain reaction showed that mesenteric arteries express P2Y(1), P2Y(2), and P2Y(6) receptors. These results demonstrate that homomeric P2X(1) receptors underlie the artery smooth muscle P2X receptor phenotype and contribute approximately 50% to sympathetic neurogenic vasoconstriction and indicate the presence of a UTP- and UDP-sensitive P2Y(6)-like receptor, but not vasoconstrictor P2Y(2) or P2Y(4) receptors, on mouse mesenteric arteries.
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PMID:P2X(1) receptor-deficient mice establish the native P2X receptor and a P2Y6-like receptor in arteries. 1243 12

Satellite cells were isolated from biopsies of the biceps femoris of adult dogs. Virtually all cells expressed muscle-specific proteins. Proliferation of satellite cells increased as the concentration of fetal calf serum (FCS) was increased from 1 to 10% of the basal medium. The addition of mitogenic growth factors resulted in greater proliferation than that of cells cultured in basal medium alone. Maximum proliferation was obtained when fibroblast growth factor-basic (FGF2) was added to the medium, but differences existed between sources or types. Proliferation did not plateau when the concentration of recombinant human FGF2 was 75 ng/ml but reached maximum levels when 50 ng/ml of bovine FGF2 or 10 ng/ml of growth hormone or insulin-like growth factor-1 were added to the medium. Proliferation of satellite cells decreased when more than 5 ng/ml of transforming growth factor-alpha was included in the medium. Exposure of canine satellite cells to chemically defined media induced greater fusion of total nuclei (ODM-34%; 4F, ITT-CF, and SFG-23%) than exposure to other treatments, such as basal medium plus 2 mg/ml of 1-beta-d-arabinofuranosylcytosine, 5% chick embryo extract, 1% horse serum (average 9% fused nuclei), or 1% FCS (2% fused nuclei). Actin, myosin, desmin, neural cell adhesion molecule, MyoD1, and myogenin were expressed by canine satellite cells, but expression of major histocompatibility complex class II antigen was not detected. Reverse transcriptase-polymerase chain reaction detected expression of messenger ribonucleic acid for interleukin-6 (IL-6), IL-15, and leukemia inhibitory factor by canine satellite cells. Collectively, these data suggest that isolated canine satellite cells display properties of other types of myogenic cells and may be useful for further study of the regulation of postnatal myogenesis.
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PMID:Isolation and characterization of canine satellite cells. 1260 41