Growth hormone, but not luteinizing hormone, acts with luteal peptides on prostaglandin F2α and progesterone secretion by bovine corpora lutea in vitro☆

2001 ◽  
Vol 63 (3) ◽  
pp. 79-92 ◽  
Author(s):  
Shuichi Kobayashi ◽  
Akio Miyamoto ◽  
Bajram Berisha ◽  
Dieter Schams
Keyword(s):  
Growth Hormone ◽  
Luteinizing Hormone ◽  
Prostaglandin F2α ◽  
Corpora Lutea ◽  
Progesterone Secretion

THE OVARIAN FOLLICLE OF THE SHEEPINHIBITION OF OESTROGEN SECRETION BY LUTEINIZING HORMONE

1974 ◽  
Vol 61 (3) ◽  
pp. 455-463 ◽  
Author(s):  
R. M. MOOR
Keyword(s):  
Luteinizing Hormone ◽  
Organ Culture ◽  
Culture Medium ◽  
Ovarian Follicle ◽  
Corpora Lutea ◽  
In Vitro Techniques ◽  
Progesterone Secretion ◽  
Experimental Approaches

SUMMARY The object of this study was to test the hypothesis that levels of luteinizing hormone (LH), comparable to those circulating at oestrus, inhibit oestrogen secretion from Graafian follicles of sheep. Three experimental approaches were used. Follicles maintained in organ culture secreted high levels of oestrogen into the medium throughout a 7-day culture period; almost no progesterone was secreted under such conditions. By contrast, oestrogen secretion declined precipitously and progesterone secretion increased rapidly after the addition of LH (0·25 μg–10 μg NIH-LH-S 17/ml) to the culture medium. In experiments combining in-vivo and in-vitro techniques, follicles were obtained from sheep from which the corpora lutea had been removed 24 h previously. The large follicles explanted from these sheep secreted high levels of oestrogen throughout the 7 days in culture. Insignificant amounts of oestrogen were, however, secreted in culture by large follicles that had been explanted from sheep in which 1 mg LH had been infused between 18 and 24 h after removal of the corpus luteum. Experiments carried out entirely in vivo showed that intravenous infusion of 1 mg LH into sheep from which the corpora lutea had been removed 18 h previously prevented the ovaries from secreting, during the ensuing 22 h, the large amounts of oestrogen they would otherwise have produced. The results demonstrate that oestrogen secretion by large Graafian follicles is terminated both in vitro and in vivo by an amount of LH corresponding to that released at oestrus.

PLASMA PROGESTERONE LEVELS IN GUINEA-PIGS ACTIVELY IMMUNIZED AGAINST PROSTAGLANDIN F2α, HYSTERECTOMIZED OR TREATED WITH INTRA-UTERINE INDOMETHACIN

1975 ◽  
Vol 67 (1) ◽  
pp. 81-88 ◽  
Author(s):  
N. L. POYSER ◽  
E. W. HORTON
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Guinea Pigs ◽  
Bovine Serum ◽  
Prostaglandin F2α ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Progesterone Secretion ◽  
Bovine Serum Albumin Conjugate ◽  
Prostaglandin F

SUMMARY Five guinea-pigs actively immunized against a prostaglandin F2α(PGF2α)–bovine serum albumin conjugate showed elongated oestrous cycles. During these, corpora lutea were maintained in a functional secretory state as indicated by plasma progesterone levels. The results are compatible with the view that the PGF2α antibodies neutralized the PGF2α released from the uterus and thus prevented its normal luteolytic effect. Similar patterns of progesterone secretion were observed in two hysterectomized animals and in two animals with intra-uterine implants of indomethacin.

scholarly journals Intraluteal regulation of prostaglandin F2α-induced prostaglandin biosynthesis in pseudopregnant rabbits

Reproduction ◽  
2007 ◽  
Vol 133 (5) ◽  
pp. 1005-1016 ◽  
Author(s):  
M Zerani ◽  
C Dall’Aglio ◽  
M Maranesi ◽  
A Gobbetti ◽  
G Brecchia ◽  
...  
Keyword(s):  
Prostaglandin F2α ◽  
Enzymatic Activities ◽  
Synthesis Rate ◽  
Corpora Lutea ◽  
Positive Staining ◽  
Mrna Levels ◽  
Cox 2 ◽  
Pg E2 ◽  
Cox 1

The objective of the present study was to investigate in rabbit corpora lutea (CL), at both the cellular and molecular level, intraluteal cyclooxygenase (COX)-1, COX-2 and prostaglandin (PG) E2-9-ketoreductase (PGE2-9-K) enzymatic activities as well asin vitroPGE2 and PGF2α synthesis following PGF2α treatment at either early- (day-4) or mid-luteal (day-9) stage of pseudopregnancy. By immunohistochemistry, positive staining for COX-2 was localized in luteal and endothelial cells of stromal arteries at both the stages. In CL of both stages, basal COX-2 mRNA levels were poorly expressed, but rose (P< 0.01) 4- to 10-fold 1.5–6 h after treatment and then gradually decreased within 24 h. Compared to mid-stage, day-4 CL had lower (P< 0.01) COX-2 and PGE2-9-K basal activities, and PGF2α synthesis rate, but higher (P< 0.01) PGE2 production. Independent of luteal stage, PGF2α treatment did not affect COX-1 activity. In day-4 CL, PGF2α induced an increase (P< 0.01) in both COX-2 activity and PGF2α synthesis, whereas that of PGE2 remained unchanged. In day-9 CL, PGF2α up-regulated (P< 0.01) both COX-2 and PGE-9-K activities, and PGF2α production, but decreased (P< 0.01) PGE2 synthesis. All changes in gene expression and enzymatic activities occurred within 1.5 h after PGF2α challenge and were more marked in day-9 CL. Our data suggest that PGF2α directs intraluteal PG biosynthesis in mature CL, by affecting the CL biosynthetic machinery to increase the PGF2α synthesis in an auto-amplifying manner, with the activation of COX-2 and PGE-9-K; this may partly explain their differentially, age-dependent, luteolytic capacity to exogenous PGF2α in rabbits.

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