Relaxin deficiency in the placenta as possible cause of cervical dystocia. A case report.

In a case of cervical dystocia which had to be delivered by caesarean section, the placenta was examined for relaxin content. The placenta was processed by acidic acetone extraction and separation of the raw extract on a carboxymethylcellulose column. The activity of relaxin was estimated by means of heterologous porcine radioimmunoassay. The elution profile of the placenta extract showed significant differences to that of the placenta in normal deliveries i.e. there was no evidence of typical protein peaks with relaxin activity. It is suggested that there is possibly a causal relationship between the lack of placental relaxin and the pathological behaviour of the cervix during delivery.

Studies on the involvement of lysosomes in estrogen action, III. The dehydrogenation of estradiol to estrone by porcine endometrial lysosomes.

Endometrial cells from prepuberal pigs contain an estradiol 17 beta-dehydrogenase. By differential centrifugation of homogenate fractions and isopycnic separation of the particles sedimenting in the 600 leads to 38000 x g range, accompanied by marker enzyme and electron microscopic analyses, the enzyme appears to be exclusively associated with a subpopulation of lysosomes. It displays a high affinity for estradiol with a Km = 5 x 10(-7) mol/l. Dehydrogenation of estradiol to estrone is favorably driven by NAD, poorly by NADP. The reverse reaction with estrone as substrate and either NADH or NADPH or NADPH + regenerating system as cosubstrate does not proceed beyond the detection level, but trace amounts of 6 alpha/7 alpha-hydroxyestrone are observed at pH 6.5 with the latter two cosubstrates.

Studies on the involvement of lysosomes in estrogen action, II. Seasonal variation in the sedimentation patterns of endometrial lysosomes from prepuberal pigs.

The lysosomal population in endometrial cells of prepuberal pigs varies with the seasons. In summertime, lysosomes equilibrate in sucrose density gradients over a broad, domeshaped area from p = 1.21 g/cm3 to p = 1.15 g/cm3. The winter pattern is characterized by a major sharp peak of aggregated lysosomes at p = 1.20 g/cm3, visible as a "snowflurry"-like band. The two extremes are linked by transition patterns in spring and fall. The possible correlation of this phenomenon to the seasonal fluctuations in the level of soluble cytoplasmic estrogen receptor is discussed.