A.6

A C O M P A R A T I V E S T U D Y ON P L A C E N T A L PATHOLOGY BETWEEN ABRUPTIO PLACENTAE A N D P L A C E N T A P R E V I A W I T H S P E C I A L R E F E R E N C E TO D E C I D U A L V A S C U L O P A T H Y . Yoshiaki Watanabe, Hiroaki Soma, Hiroyuki Osawa, Kayo Yamamoto , Hiroshi Horikiri , Hiroshi Sakuma and T o s h i o Hata . D e p a r t m e n t of O b s t e t r i c s and Gynecology, Saitama Medical School.

In this report, pathological lesions be tween abruptio p lacentae (34 cases) and placenta previa (24 cases) w e r e c o m p a r a t i v e l y i n v e s t i g a t e d w i t h s p e c i a l r e fe rence to decidual vasculopat 'hy. .Resul ts : 1) The incidence of abruptio placenta was gradually increased after 27 weeks of gestation, while placenta previa was often found before 25 weeks. Fetuses under 800g were o c c u p i e d in 37 .5% of the l a t e r g roup . Thus , the incidence of placental weight under 290g was 29.4% and 41.6%, respect ively. 2) Placental lesions such as infarcts, thrombosis, and marginal hemorrhages in the basal p la te were p r o m i n e n t in both groups . 3)The f requency of decidual vasculopathy such as f ibrinoid degenera t ion and foamy changes was of ten seen in both g roups (41 .2% and 45 .8%, r e s p e c t i v e l y ) . 4) Chorangiosis was also found in both groups (17% and 20.8%, respectively). Conclusion: It is suggested that p l a c e n t a l s e p a r a t i o n m i g h t be due to r u p t u r e of vasculopathy in the basal plate of p lacentas in both conditions.

Placenta (I996), Vol. 17

A U T O N O M O U S R E G U L A T I O N O F PROSTAGLANDIN PRODUCTION IN PLACENTA A N D F E T A L M E M B R A N E S . O s a m u I s h i h a r a , D e p a r t m e n t of Obs t e t r i c s & G y n e c o l o g y , Sa i tama Medical Centre, Saitama Medical School

Pregnant uter ine muscle remains re la t ively si lent in c o n t r a s t to f r e q u e n t i r r egu la r c o n t r a c t i o n of non- pregnant uterus. Therefore, the release of suppression m e c h a n i s m of u t e r i ne c o n t r a c t i o n s migh t lead to n o r m a l l a b o u r o r p r e m a t u r e l a b o u r . S i n c e p r o s t a g i a n d i n s (PGs) are po ten t agen ts for u te r ine contraction, the regulatory mechanism of PG synthesis in the u terus has to be e l u c i d a t e d . T h e r e f o r e , we inves t iga ted cyc looxygenase (COX), a rate l imi t ing enzyme of PG production, using placenta t issues and fetal mambranes obtained before and after the labour. The inducib le type of COX-2 was con ta ined in the t i ssue ob ta ined after the onse t of labour assoc ia ted wi th h igher p roduc t i on of PGs via COX-2 . On the con t r a ry , c o n s t i t u t i v e type of C O X - I was p r e s e n t wi thout a dramat ic change be tween both t issues. In v i t ro s tudy r evea l ed that e x o g e n o u s IL-1 induced C O X - 2 e n z y m e , and that e n d o g e n o u s IL-1 m i g h t m a i n t a i n PG p r o d u c t i o n v ia C O X - 2 i n d u c t i o n . Complex cytokine network seems to be important as an autonomous regulatory mechanism of prostaglandin production.

A U T O N O M Y O F H U M A N P L A C E N T A L S T E R O I D G E N E S I S ; D I V E R S E F U N C T I O N OF

HUMAN PLACENTAL AROMATASE. Yukiko Shimizu, Depa r tmen t of Obs te t r i c s and G y n e c o l o g y , Showa University School of Medicine, Tokyo, Japan.

Human placental aromatase (Are) is a cytochrome P-450 complex which catalyzes the important biotransfcrmation of androgens to estrogens (E). The 2-hydroxylation is one of

the major metabolic pathways of E. Recently we found the evidence that placental E 2-hydroxylat ion (2-OHE) is catalyzed by Are p-450 after purification and reconstitution. It was also confirmed that both activities were exhibited in Chinese hamster ovarian cells t rasfected with human placental A.ro cDNA. We also found that 2-OHE activity is elevated in the placental microsomes of the pregnancy induced hypertension patients as compared to normotensive

subjects. The catecholamines ; dopamine, norepinephrine and epinephrine competitively inhibited Are and 2-OHE

activities. Are also exhibits xenobiotic N-demethylase activities aueh as 7-ethoxycoumarin o-deethylation and cocaine N-demethylation with a high degree of substrate spec i f i c i ty . These s tud ies sugges t that the relat ive importance of Are deverse functions may be involved the physiological s ign i f i cance in placental autonomical steroidogenesis.

CELLULAR AND SUBCELLULAR LOCALIZATION OF NADPH-DIAPHORASE ACTIVITY IN THE HUMAN PLACENTA. S. Matsubara. H. Minakami, T. Takayama, I. Sate and T. Saito, Department of Obstetrics and Gynecology and Anatomy, Jichi Medical School, Tochigi, Japan

Recent research has shown that the endothelial-derived relaxing factor, nitric oxide (NO), and its synthesizing enzyme, nitric oxide synthase (NOS), exists in the human placenta and that this system has a crucial role in regulating fete-placental hemody'namics. NOS utilizes reduced nicotinamide adenine dinucleotide phosphate (NADPH) as a co-factor in producing NO. The action of NOS and NADPH-diaphorase (NADPH-d) reflect two functions carried out by the same enzyme molecule and NADPH-d activity, therefore, can be used as a marker for NOS. In the'present study, we demonstrated the cellular and subcellular localizations of NADPH-d activity in the human placenta. Ten Fu'st-trimester and I0 full term placental tissues were taken, and fixed in 0.25% luteraldehyde for 30 rain. Sections of 40/.z m thickness were cubated in NBTor BSPT medium for cytochemical detection of

enzyme activity. For electron microscopy, sections were postf'zxed in 1% buffered osmium, dehydrated and embedded in Epon. Ultrathin section were prepared, followed by investigation under TEM. For light microscopy, dark purple deposits indicating NADPH-d activity could be observed in the endothelium of cord artery and vein, amniotic epithelium, chorionic trophoblasts and syncytiotrophoblasts. Activity was negative in villous vascular en.dothelium, villous stroma and cytotrophoblasts. By electron microscopy, electron dense deposits indicating the enzyme activity, were observed throughout the cytoplasm of syneytiotrophoblasts. Deposits did not have a relationship with intracytoplasmic organeles or plasma membrane. In terminal villi, NADPH-d activity was thus confined to the syncytiotrophoblasts. This indicates that syncytium might have major role in NO production in terminal villi and, thus, this cell would play an important role in regulation of fete-placental eh'culation.