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A Delbaere

Publications and source records attributed to A Delbaere.

23 records · Page 2Linked to original sources
PubMed1996

Bioactive angiotensin (1-8) is the main component of angiotensin II immunoreactivity in human follicular fluid.

The ovarian renin-angiotensin system is involved in various aspects of human reproduction. As immunoreactive measurement of angiotensin II (ANG II) in follicular fluid (FF) relates to several angiotensin peptides with different biological activities, HPLC was used to characterize the molecular forms of the ANG II immunoreactivity in human FF. Samples of FF, obtained from gonadotropin-stimulated patients for in vitro fertilization, were collected at the time of oocyte retrieval. The C-terminal 2-8 heptapeptide was never detected. HPLC analysis revealed for the first time that the major component of the ANG II-IR in human FF was the biologically active octapeptide ANG II.

Angiotensin II↗
PubMed1996

Periovulatory elevation of angiotensin II in the peritoneal fluid during the human menstrual cycle.

Local variations in the ovarian renin-angiotensin system were investigated in peritoneal fluid (PF) during normal menstrual cycles and after ovarian stimulation with gonadotropins. PF was collected either during laparoscopy or by transvaginal aspiration before ovocyte retrieval for in vitro fertilization. Renin activity (RA) and angiotensin II immunoreactivity (Ang II-ir) were assayed in PF and simultaneously collected blood. The level of Ang II-ir was higher in PF than in plasma throughout the cycle, where as RA was in the same range of magnitude in the two compartments. In PF, Ang II-ir reached levels 2-5 times higher in the periovulatory period (days 12-14 and 15-17 of the cycle) than those found during the other stages of the cycle, whereas plasmatic Ang II-ir remained stable. No significant change could be demonstrated in RA throughout the cycle in either PF or plasma. Ovarian stimulation induced a strong elevation of Ang II-ir in PF, but not in plasma. High performance liquid chromatography revealed that the majority of Ang II-ir in PF was true Ang II. In conclusion, these results show a periovulatory elevation of Ang II in PF during the cycle and a more pronounced rise after treatment with gonadotropins. These observations support the involvement of Ang II in the process of ovulation or fecundation.

Adult↗
PubMed1995

[Update on ovarian hyperstimulation syndrome].

The ovarian hyperstimulation syndrome (OHSS) is the most important complication of the pharmacological ovulation induction. Exclusively postovulatory, it is clinically characterized by a massive ovarian enlargement associated with an acute third-space fluid shift responsible for the development of ascites, and sometimes pleural and/or pericardial effusion. While mild OHSS has no consequence, severe forms can be life-threatening because of associated hemodynamic troubles. The main risk factors are the polycystic ovarian syndrome and an explosive ovarian response to the stimulation characterized by high serum oestradiol levels and an increased number of follicles. Ultrasound and endocrine monitoring make prevention measures possible, mainly by either abandoning the stimulation cycle or, during in vitro fertilization, cryopreserving the embryos for subsequent replacement in another cycle. Treatment consists in correcting circulatory and electrolyte imbalance. Paracentesis is more and more systematically proposed in the severe forms.

Ascites↗
PubMed1994

Angiotensin II immunoreactivity is elevated in ascites during severe ovarian hyperstimulation syndrome: implications for pathophysiology and clinical management.

OBJECTIVE: To investigate the ovarian renin-angiotensin system (RAS) during severe ovarian hyperstimulation syndrome (OHSS). DESIGN: Simultaneous sampling of blood and ascitic or peritoneal fluid (PF) during therapeutic paracentesis or laparoscopy. SETTING: University Hospital. PATIENTS: Twelve patients were investigated: three patients presenting severe OHSS, three patients with a spontaneous first trimester pregnancy, three normally cycling women during the early luteal phase, and three patients with ascites of nonovarian origin. MAIN OUTCOME MEASURE: Renin-like activity and angiotensin II (ANG II) immunoreactivity were measured simultaneously in the plasma and the ascites or PF. RESULTS: Angiotensin II immunoreactivity was much higher in the ascites or PF than in corresponding plasma during severe OHSS, first trimester pregnancy, and in the early luteal phase, while it was lower in ascites of nonovarian origin. Renin-like activity and ANG II immunoreactivity were the highest in the ascites of severe OHSS and in the PF from part of the patients with a spontaneous first trimester pregnancy. CONCLUSIONS: The present findings argue for the ovarian origin of the elevated renin-like activity and ANG II immunoreactivity in the ascites of severe OHSS and suggest a stimulatory role of hCG on the ovarian RAS whether during severe OHSS or first trimester spontaneous pregnancy. The vasoactive peptide ANG II may contribute to the maintenance of the ascites in severe OHSS but is probably not responsible for the formation of the ascites. The efficiency of paracentesis during severe OHSS could be explained at least partially by the removing of great amounts of ANG II from the peritoneal cavity.

Adult↗