Dr. Roger Wagner

Professor Emeritus

Contact

Wagner

Lab: 005 McKinly Lab

Mailing address:
Department of Biological Sciences
Wolf Hall
University of Delaware
Newark, DE 19716

Phone: (302) 831-2284
Fax: (302) 831-2281
E-mail: rags@udel.edu
Web: Dr. Wagner's Homepage
Web: Dr. Wagner's Wagart

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Education

B.S.: Hamline University
M.S.: Ohio University
Ph.D.: University of Minnesota
Postdoctoral: Yale University

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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.

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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 hr. 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.
• BISC 617 - Techniques in Biological Electron Microscopy: Preparation, microscopy and analysis of tissue for transmission and scanning EM.
• BISC 618 - Computer Imaging in Biology: Fundamental principles of digital image acquisition, processing, and analysis.

*Access to this site is restricted to computers on the UD network.

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Selected Publications

Wagner, R.C., Czymmek, K. and Hossler, F.E. 2006. Confocal Microscopy, Computer Modeling and Qauntification of Glomerular Vascular Corrosion Casts. Microscopy and Microanalysis 12:262-268.

Farach-Carson, M.C., Wagner, R.C. and Kiick, K.L. 2006. Extracellular Matrix: Structure, Function and Applications to Tissue Engineering. In "Tissue Engineering and Artificial Organs". Ed. J. D. Bronzino, Chp. 32 pp. 32-1 to 32-22. The Biomedical Engineering Handbook (3rd ed.) CRC Press.

Chen, S.-C., Liu, K.-M. and Wagner, R.C. 1998. Three-Dimensional Analysis of Vacuoles and Surface Invaginations of Capillary Endothelia in the Eel Rete Mirabile. Anatomical Rec. 252:546-553.

Wagner, R.C. and Kachar, B. 1995. Linear Gap and Tight Junctional Assemblies between Capillary Endothelial Cells in the Eel Rete Mirabile. Anatomical Rec. 242:344-352.

Murphy, D.D. and Wagner, R.C. 1994. Differential Contractile Response of Cultured Microvascular Pericytes to Vasoactive Agents. Microcirculation 1:121-128.

Wagner, R.C. and Hossler, F.E. 1992. SEM of Capillary Pericytes prepared by Ultrasonic Microdissection: Evidence for the Existence of a Pericapillary Syncytium. Anatomical Rec. 234:249-254.

Wagner, R.C. and Chen, S.C. 1991. Transcapillary Transport of Solute by the Endothelial Vesicular System: Evidence from Thin Serial Section Analysis. Microvascular Res. 42:139-150.

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