Roger Wagner, Ph.D.
Professor Emeritus
Wagner
Phone: (302) 831-2284
Fax: (302) 831-2281
Email: rags@udel.edu
Web: Dr. Wagner's Homepage, Dr. Wagner's Wagart
Office: 005 McKinly Lab
Address:
Department of Biological Sciences
Wolf Hall
University of Delaware
Newark, DE 19716
Education
- B.S. - Hamline University
- M.S. - Ohio University
- Ph.D. - University of Minnesota
- Postdoctoral - Yale University
Teaching
- BISC 408 - Mammalian Histology: Microscopic anatomy of human tissues and organ systems at both the light and electron microscopic levels. Two lectures and two 3 hour labs per week.
- BISC 442* - Vertebrate Morphology: Lectures in this course cover the comparative anatomy of selected vertebrate organisms from functional, developmental and evolutionary perspectives. The laboratory includes dissection and examination of the lamprey, dogfish shark and cat.
*Access to this site is restricted to computers on the UD network
Research Interests
The focus of my research is the role of pericytes and endothelial cells in the function of microvessels and capillaries. Electron-dense tracers have been used to determine the paracellular (endothelial junctions) and transcellular (endothelial vesicular system) pathways across the endothelium of blood capillaries in the eel rete mirabile. Electron energy loss spectroscopy has been utilized to detect different elemental tracers perfused in timed intervals and their location in pathways in temporal sequences. Computerized reconstruction of images of ultrathin serial sections through the capillary wall reveals that the vesicular system is comprised of conjoined membraneous compartments which connect to both endothelial surfaces. Electron-dense tracers used in conjunction with thin serial section reconstruction has revealed that the vesicular system transports solutes across the capillary wall. Freeze-fracture studies indicate that rete capillary endothelial cells are joined by linear low-resistence gap junctions flanked on both sides by tight junctional assemblies. This implies ionic communication between the endothelial cells as well as occlusion of solute transport through the paracellular route.
Pericytes which encircle capillaries may regulate blood flow via their contraction. They may also modulate capillary permeability by changing the amount of capillary wall they cover. Pericytes cultured from isolated rete capillaries contract and attenuate in response to vasoactive agents. Scanning electron microscopy has revealed that rete capillary pericytes in situ are connected by their processes into a syncytium. This cytoplasmic continuum implies coordination of pericyte contraction as well as mitotic activity.
Selected Publications
- Farach-Carson MC, Wagner RC, Kiick KL. Extracellular Matrix: Structure, Function and Applications to Tissue Engineering. In: Bronzino JD, ed. Tissue Engineering and Artificial Organs. 3rd ed. CRC Press; 2006:32–1 to 32–22. The Biomedical Engineering Handbook.
- Wagner RC, Czymmek K, Hossler FE. Confocal microscopy, computer modeling, and quantification of glomerular vascular corrosion casts. Microsc Microanal. 2006;12(3):262–268.
- Chen SC, Liu KM, Wagner RC. Three-dimensional analysis of vacuoles and surface invaginations of capillary endothelia in the eel rete mirabile. Anat Rec. 1998;252(4):546–553.
- Wagner R, Kachar B. Linear gap and tight junctional assemblies between capillary endothelial cells in the eel rete mirabile. Anat Rec. 1995;242(4):545–552.
- Murphy DD, Wagner RC. Differential contractile response of cultured microvascular pericytes to vasoactive agents. Microcirculation. 1994;1(2):121–128.
- Wagner RC, Hossler FE. SEM of capillary pericytes prepared by ultrasonic microdissection: evidence for the existence of a pericapillary syncytium. Anat Rec. 1992;234(2):249–254.
- Wagner RC, Chen SC. Transcapillary transport of solute by the endothelial vesicular system: evidence from thin serial section analysis. Microvasc Res. 1991;42(2):139–150.
