Disease relevance of PVR

• The Tage4 gene (Tumor-Associated Glycoprotein E4) is a member of the immunoglobulin superfamily overexpressed in rat colon tumors and Min mouse intestinal adenomas [1].
• The Tage4 cDNA presents approximately 60% identity with the human CD155, a member of the immunoglobulin superfamily coding for a transmembrane protein capable of serving as an entry receptor for poliovirus, porcine pseudorabies virus and bovine herpesvirus 1 [1].
• Poliovirus binding to its receptor (PVR) on the cell surface induces a conformational transition which generates an altered particle with a sedimentation value of 135S versus the 160S of the native virion [2].
• The PVR normalized to body weight was 30% higher in the experimental groups (p less than 0.005) [3].

High impact information on PVR

• We also isolated approximately 2 kb of the 5' flanking region of the Tage4 gene and demonstrated the existence of closely clustered transcription start sites [1].
• The Tage4 gene maps to rat chromosome 1q22 [4].
• Thus it will be important to determine the expression of the different PVR subtypes in normal anterior pituitary-cell types if we are to begin to understand the regulation of pituitary-cell regulation by PACAP [5].
• The resistance to blood flow in the lung was assessed either by calculating the pulmonary vascular resistance (PVR = arterial - venous pressure difference divided by flow rate) or by examining the vascular pressure-flow relationship for changes in slope and intercept [6].
• The marked increase of PVR in rat lungs was prevented with papaverine (PVR increased only 58%), suggesting that vasoconstriction was a primary event in rat lungs [6].

Biological context of PVR

• The properties of the pulmonary vasculature were assessed by measuring baseline vascular resistance, PVR = (Pa-Pv)/Q, segmental pressure gradients (double occlusion technique), pressure-flow relationship, hypoxic pressor response (HPR, 3% O2), and the response to 0.5 microgram bolus of angiotensin II (AII) [3].

Associations of PVR with chemical compounds

• Both LY and IND prevented the smoking-induced increase of PVR and SVR [7].

Other interactions of PVR

• In chronically hypoxic lungs, acute Rho kinase inhibition markedly decreased PVR but did not alter the alveolar to arterial oxygen gap [8].

Analytical, diagnostic and therapeutic context of PVR

• No splicing variant was identified by RT-PCR indicating that the Tage4 gene is transcribed as a unique mRNA [1].
• In contrast to the small effect in dog lungs, the PVR in rat lungs rose more than 400% during perfusion with heat-treated blood [6].
• PVF of PVL, IPO and sham-operated rats increased from 22.6 to 32.8, 22.0 to 28.0, 14.0 to 34.8 mL.min(-1) (P<0.01), and PVP increased from 1.86 to 2.24, 1.74 to 1.95, 1.04 to 1.80 kPa(P<0.01), PVR decreased from 71 to 61, 67 to 61, 52 to 44 kPa.min.L(-1) after intraperitoneal injection of 1mg.kg(-1) of LPS [9].
• The increase in PVR in the rat lungs was not due to mechanical obstruction of the vasculature but rather to constriction of arteries and veins (double occlusion technique) [6].
• Immunoelectron microscopy on the topographical distribution of the poliovirus receptor [10].

References