Abdel Rahim, Sheik El Din Awad

2018-05-14T10:11:21Z

2018-05-14T10:11:21Z

1983

Experiments were conducted to study the stimulus for PGF„ release from the uterus and the utero-ovarian 2oc pathway for PGF2oc transport in sheep

Frequent uterine venous blood samples were collected from the mammary vein after anastomosing it with the uterine rein, while simultaneous uterine tissue samples were obtained by fistulation of the uterine horn through the abdominal wall thus exposing the uterine endometrium to the exterior. Uterine venous blood and tissue samples were analysed for PGF2cC» progesterone and oestradioi-17/3 and endometrial PGF~ and PGE~ content ' 2oc 2 and synthesizing ability respectively. There was an increase in PGF_ release towards the end of the cycle 2oc with peaks appearing consistently at 30-45 and 3-9 hrs before the decline in progesterone conc^trations. Further PGF^ peaks occurred after the initiation of progesterone decline in 4 of 5 cycles studied. Elevation of endometrial PGF_ content and synthesizing ability Zee occurred at similar times to PGF„ release, but did not 2oc consistently either precede, coincide or follow it. This suggested that neither an increase in PGF2oC content or an increase in the ability of the uterus to synthesize PGF2qc are prerequsites for PGF2oC release. Oestradiol-17^3 showed an increase in levels around the time of both periods of PGF2qc increase. These elevated levels of oestradiol-17/3 precede and/or coincide with peaks of PGF2oc , thus confirming a role for oestradiol in PG^oc release. An increase in oestradiol-17/3' and PGF„ was zoc also observed after the commencement of progesterone decline but before oestrus.

Investigations into the utero-ovarian pathway for PGF2oc imitated that the oestr°us cycle of the ewes were extended when the uterine vein was cannulated and all otner direct tissue connections between the uterine horn and the ipsilateral ovary were surgically separated. The results demonstrated that blood passing through the uterine vein is not sufficient to account for the luteolytic effect of the uterus on the ipsilateral ovary . Examination of the anatomy of the uterine lymphatic drainage revealed that there was no direct lymph flow between the uterus and ovaries, and that the main uterine lymphatic trunks were in close association with the main utero-ovarian artery. In view of this finding the availability of prostaglandins in lymph drainage from the uterus at different stages of the oestr°us cycle was examined. Samples of uterine lymph were collected on different days of the oestr°us cycle and analysis showed that PGF2qc was present in this lymph in amounts comparable to those in uterine venous blood. Furthermore, the mean concentration remained low until day 12, while increased amounts were present from day 12 onwards. There was no significant variation in PGE2 in o uterine lymph during the oestrus cycle. Sequential uterine lymph samples were obtained by chronic cannulacion of a uterine lyrnpn vessel. These sequential samples were analysed for PGF^^, PGE2' Pro<3esterone anc^ oestradiol-17/3 . The results indicated that the concentration of PGF2qc in uterine lymph fluctuated considerably, with a complex series of peaks being apparent especially from the time of initiation of luteal regression (day 12) to the end of the cycle. The results demonstrated that PGF2(X is present in uterine lymph in increased quantities at the time of luteal regression. Again there was no significant change in PGE2 concentration. However there were high levels of oestradiol-17/3 / and progesterone levels did not decline to low levels that were seen in venous blood. It was transfer system similar to that propose! for tna concluded that, it is possible that a counter-current^ transfer of PGF„ from the utero-ovarian vein to the 2oc ovarian artery may occur between the main uterine lymph trunks and the ovarian arterial blood, and so form an additional or even alternative method of transfer of PGF2oc from the uterus to the ovary.

http://hdl.handle.net/1842/29648

The University of Edinburgh

Annexe Thesis Digitisation Project 2018 Block 18

Already catalogued

Uterine prostaglandin in the non-pregnant sheep: studies on release and lymphatic transport

Thesis or Dissertation

Doctoral

PhD Doctor of Philosophy