Abstracts: R.T.C. and T.G.W.M.S. Canada 1996

Elastic Type Fetal Blood Vessels in Human Placental Stem ViZZi. u H. Neudeck’, D. Matejevic2, K. Vetter’ ‘Institut fir Anatomie, Freie UniversitM Berlin, 2Frauenklikk, Krankenhaus Neukdlln, Berlin, FRG.

Objective. In the course of our recent study demonstrating for the first time that elastic tissue fibres are an essential component of the perivascular contractile sheath (PVCS) in human placental stem villi, we have also seen elastic fi- bres in fetal blood vessels of these villi. The existance of elastic tissue fibres in fetal placental blood vessels is still a matter of debate. Therefore, we reinvestigated the distri- bution pattern of elastic tissue fibres within the placental fetal blood vessel tree. Methods. Investigations were car- ried out using cryostat sections of 10 human term placentae (39-41 weeks of gestation) of normal pregnancies, which were processed for conventional Orcein staining. Results. In the chorionic plate and all types of stem villi, arteries containing different amounts of elastic tissue fibres in the tunica media and adventitia as well as arteries completely devoid of elastic fibres were found. Independently of the stem villous type, high amounts of elastic fibres in numer- ous blood vessel walls indicated an elastic type blood ves- sel. In these cases elastic fibres formed lamellae throughout the blood vessel wall, very likely to the aorta, In several blood vessels only one side of the tunica media contained elastic tissue fibres, while the other side was of muscular type. Conclusion. We describe for the first time the pres- ence of arteries of elastic type within the stem villous tree and the chorionic plate. In combination with the highly differentiated system of signal transduction within the PVCS our present findings indicate that stem villi have a complex tinction in fetal blood flow modulation. Supported by the DFG (Sfb 174 and Gr1041/3-1).

A.19

The Perivascular Contractile Sheath of Human Placental Stem Villi: Extracellulgr Matrix Collagens and Proteogly- cans. D. Mateievic’, D. Schuppan2, R. Gra?, K. Mster4, 0. Baum4, H. Neudeck3 and K. Vetter’, ‘Frauenklinik, Krankenhaus Neukiilln, Berlin; 2Abtlg. f%r Gastroenterolo- gie, 31nstitut fir Anatomic, Institut fiir Biochemie und Molekularbiologie, Freie Umversitiit Berlin, FRG

Objective. The presence of focal adhesion molecules, as well as al and pl integrins within extravascular smooth muscle Cel1.S of the placental stem villi (see contribution of Graf et al. in this issue) suggests a system of signal exchange between extracellular matrix components (including collagens and elastic fibres) and cells of the perivascular contractile sheath (PVCS). Therefore, the aim of the present investi- gation was to examine the pattern of collagen VI? an un- banded network forming collagen, involved in sliding of collagen fibres, undulin (collagen type XV), a glycoprotein which interconnects interstitial collagen I fibres, and plays a role in the supramolecular organization of connective tis- sues, and heparadchondroitin sulfate PG perlecan, a con- stituent of basement membranes. Methods. Monospecific antibodies were applied to cryostat sections of term pla- centae. Binding sites were detected by ABC-immunostai- ning. Results. Collagen VI-immunostaining was distributed throughout the connective tissue of the PVCS, while anti- undulin-reactivity predominated in thick undulating fibre bundles. Both antibodies also stained vascular connective tissues. Cells were unstained. Perlecan was localized to basement membranes of extravascular (PVCS) and vascu- lar smooth muscle cells. Conclusions. The extravascular smooth muscle cells of the PVCS are surrounded by a highly differentiated extracellular matrix, the pattern of which supports a specific cell-matrix interaction.

The Perivascular Contractile Sheath of Human Placental Stem Villi: Detection of Cytoplasmic Molecules Involved in Si al Transduction from the Extracellular Matrix, R. Gra. K. LBste?, 0. Baum’ D. Schuppan3, M. Shakibaec f9” H. Neudeck’, D. Matejevic’” and K. Vetter4, ‘Institut Eir Anatomie, ‘Institut i?ir Biochemie und Molekularbiologie, 3Abtlg. fir Gastroenterologie, Freie Universitlt Berlin, 4Frauenklinik, Krankenhaus Neukijlln, Berlin, FRG

Objective. Our previous studies on the perivascular con- tractile sheath (PVCS) of human placental stem villi sug- gest the PVCS as a myofibroelastic functional unit. The immunocytochemical demonstration of the focal adhesion molecules a-actin and talin initiated the question, whether paxillin, vinculin and tensin, considered substrates of the focal adhesion kinase are also present in the PVCS. Aim of the present study was to examine the presence of these molecules together with a-a&in and the integrins al and pl in the PVCS of term placentae. Methods. Immunocy- tochemical detection was performed with monospecific an- tibodies using the ABC-immunostaining method on cry- ostat sections. Results. All antibodies reacted specifically within extravascular PVCS smooth muscle cells. Addition- ally, immunoreactivity of all molecules was also found in medial smooth muscle cells of stem villous fetal blood ves- sels. Conclusions. In connection with the contractile and intermediate filament system, and the highly differentiated extracellular matrix (see contribution of Matejevic et al. in this issue) our results support the concept of a myofibroe- lastic unit within the PVCS. Our results indicate that within the PVCS there exists a tightly regulated system of signal transduction and cross-talk between cells and their sur- rounding extracellular matrix. Supported by the DFG (Sfb 174 and Gr1041/3-1).

Quantitative Differences in Arterial Mar hometry define the Placental Bed in Preeclampsia. CM. Sala&, K.A. Starz&& Pezzullo, J.M. Lage, V. Parkash, L.Vercruysse, R.Pijnenhor University d

Departments of, Path. and OblGyn, Geor etowd edrcal Center, Washmgton DC,, Yale Umversity E SC 001 of

Medicine, New Haven CT, University Hospital, Leuven Belgium.

OBJECTIVE: To quantitatively analyze normal and preeclamptic

with smaller caliber rumens and thicker waifs. Failure of propel

1 lacentation ed,

may result in abnormal spatial anatomy in the or there may be an anatomical vanant of spiral and facentd bass arteries

that is more susceptible to hemodynamic stresses and endothelial damage, and manifests as preeclampsla.