In:
Reproduction, Bioscientifica, Vol. 128, No. 2 ( 2004-08), p. 189-195
Abstract:
Prostaglandin (PG) F 2α released from the uterus in a pulsatile fashion is essential to induce regression of the corpus luteum (CL) in the cow. In addition to the uterus, the CL has also been recognized as a site of PGF 2α production. Therefore, this study aimed to determine the detailed dynamics of the releasing profile of CL-derived PGF 2α together with uterus-derived PGF 2α during spontaneous luteolysis in the cow. Non-lactating Holstein cows ( n = 6) were surgically implanted with a microdialysis system (MDS) on day 15 (oestrus = day 0) of the oestrous cycle. Simultaneously, catheters were implanted to collect ovarian venous plasma ipsilateral to the CL as well as jugular venous plasma. The concentrations of PGF 2α , 13,14-dihydro-15-keto-PGF 2α (PGFM) and progesterone in the MDS and plasma samples were determined by enzyme immunoassays. The intra-luteal PGF 2α secretion slightly increased after the onset of luteolysis (0 h) and drastically increased from 24 h, and was maintained at high levels towards the following oestrus. Furthermore, PGF 2α was released from the CL into the ovarian vein in a pulsatile manner during spontaneous luteolysis. Also, the fact that intra-luteal secretion of PGF 2α and PGFM showed a positive correlation indicates the existence of a local metabolic pathway for PGF 2α in the CL. In conclusion, the present study clarified the real-time dynamics of uterus-derived PGF 2α and CL-derived PGF 2α during spontaneous luteolysis in the cow, and gives the first in vivo evidence that the CL releases PGF 2α during spontaneous luteolysis in the cow. Although the physiological relevance of CL-derived PGF 2α appears to be restricted to a local role as an autocrine/paracrine factor in the CL, overall results support the concept that the local release of PGF 2α within the regressing CL amplifies the luteolytic action of PGF 2α from the uterus.
Type of Medium:
Online Resource
ISSN:
1470-1626
,
1741-7899
Language:
Unknown
Publisher:
Bioscientifica
Publication Date:
2004
detail.hit.zdb_id:
2037813-0
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