Biomedical subjects

C Hoche

Publications and source records attributed to C Hoche.

5 recordsLinked to original sources

PubMed1987

Prostaglandin metabolism in umbilical vessels of smoking and non-smoking mothers.

Arachidonic acid (AA) and its metabolites are responsible for the regulation of the umbilical blood flow. We investigated the prostaglandin (PG) synthesis in umbilical arteries and veins of 16 smoking and 17 non-smoking mothers. AA and PGs were analyzed after extraction of samples by means of thin layer chromatography (TLC). Of all the AA metabolites in umbilical arteries and veins, prostacyclin reached the highest concentration. In non-smoking mothers the conversion rate of AA in arteries and veins was similar. The only exception was PGE2 which showed a significantly lower concentration in umbilical veins of smoking mothers. However, the influence of PGE2 on the blood flow of umbilical arteries and veins seems to be of minor importance compared to other vessels.

Arachidonic Acid↗

PubMed1984

Prostacyclin synthesis stimulating plasma factor in pregnancy and puerperium.

Prostacyclin is assumed to play a key role in maintaining a sufficient blood flow in maternal and fetal circulation. Recent reports pointed out that the prostacyclin synthesis is regulated by a so-called plasma factor. The activity of this plasma factor was tested during pregnancy, labor, and puerperium. During the first and second trimesters, increased values could be observed, whereas in the third trimester and at the onset of labor, the values decreased. After delivery, there was again a moderate increase in plasma factor activity. A feedback mechanism is discussed between prostacyclin or 6-oxo-prostaglandin F1 alpha and the plasma factor, but hormones, such as 17 beta-estradiol, may possibly influence prostacyclin synthesis in pregnancy.

Animals↗

PubMed1982

[Plasma factors regulating prostacyclin synthesis during pregnancy].

Prostacyclin is the most potent endogenous inhibitor of platelet aggregation known so far, produced by endothelial and smooth muscle cells. This substance is assumed to play a key role in maintaining a sufficient blood flow in maternal and fetal circulation. There is now some evidence that there is a non-cellular component in human blood, which is able to influence the prostacyclin formation to a certain degree, the so-called "prostacyclin synthesis stimulating plasma factor". A change in the plasma factor activity in patients with a disturbance of PGI2 metabolism has been observed. We examined the activity of this plasma factor during pregnancy and one year after delivery. During the first and second trimenon increased values were observed, whereas at the end of pregnancy the values were significantly decreased. The values for plasma factor activity one year after delivery were comparable to those of the control group. In patients with diabetes mellitus decreased activity of the plasma factor was observed, but its course was similar to that seen in normal pregnancy.

Biological Products↗

PubMed1982

[Prostacyclin synthesis in human umbilical vessels].

Umbilical arteries exhibit the highest capacity to synthesize PGI2 of all human blood vessels. This capacity is not only severely suppressed in adults, but also in umbilical arteries in mothers suffering from diseases accompanied by vessel wall alterations such as diabetes mellitus, hypertension and with smoking, for example. In parallel, severe morphological changes of endothelium and smooth muscle cells of umbilical arteries can be observed. It is assumed that a decrease in PGI2 formation might cause a disturbance in local haemodynamics.

Diabetes Mellitus↗

PubMed1982

[Prostacyclin synthesis-stimulating plasma factor in different age groups].

The vascular synthesis of prostacyclin (PGI2), the most powerful endogenous inhibitor of platelet aggregation and vasodilator, plays a central role in prevention of vascular damages by uncontrolled platelet aggregation. PGI2 seems to be an important defense mechanism of vascular system against, among others, the development of atherosclerosis. The PGI2-production of blood vessels is stimulated and thereby decisively influenced by a plasma factor (PF). This PF participates in the pathogenesis of several diseases. This activity of PF is for instance increased in renal insufficiency, which explains partly the haemorrhagic diathesis occurring in this illness. On the other hand there seems to be a hereditary lack of PF in patients suffering from thrombotic-thrombocytopenic purpura or haemolytic-uraemic syndrome. The PF was estimated in 62 healthy subjects collected in 8 age groups by means of bioassays and RIA-determination of 6-oxo-PGF1 alpha, the stable PGI2-metabolite, in tissue cultures. No differences of PF in the different age groups could be demonstrated. These findings support the view, that the PF as an important regulator of vascular PGI2-synthesis is functioning absolutely normal in older age.

Adolescent↗