Quantification of circulating beta-endorphin and white blood cells in heifers after intrauterine administration of endotoxin

Peter, Augustine T.; Malven, P.V.; Shaftoe, S.; Bosu, W.T.K.

doi:10.1016/0093-691x(91)90325-8

Cited by 4 publications

(2 citation statements)

References 20 publications

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“…It has been reported that uterine bacterial contamination after parturition in cows also undesirably affects the follicle selection and its subsequent growth and function [32]. Additionally, a decrease in LH plasma level in the treated gilts could be eventually the consequence of the inhibitory effect of the proinflammatory cytokines released from an inflamed uterus on the hypothalamicpituitary unit, as was suggested earlier [33]. The reduction of PRL secretion observed in E. coli-treated animals can be caused by the decreased oestrogen secretion [34,35] and/ or cytokine effect [9,36].…”

Section: Discussionsupporting

confidence: 49%

Effect of intrauterine infusion of Escherichia coli on hormonal patterns in gilts during the oestrous cycle

2004

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-The aim of this study was to determine the effect of intrauterine Escherichia coli infusion on the patterns of plasma LH, prolactin, progesterone, androstenedione, testosterone, oestrone, cortisol and 13, (PGFM) in gilts during the oestrous cycle. On day 4 of the oestrous cycle (day 0), 25 mL of saline or 25 mL of Escherichia coli suspension, containing 10 7 colony forming units·mL -1 , was infused once into the each uterine horn in group I or II, respectively. The control gilts developed a new oestrous cycle at the expected time but not bacteria-treated. Endometritis and vaginal discharge developed in all gilts after Escherichia coli infusion. The administration of Escherichia coli resulted in a reduction of plasma levels of LH, prolactin, oestrone and oestradiol-17β (P < 0.05-0.001), mainly on days 15-18 after treatment (expected perioestrous period). During this time, the plasma androstenedione level was elevated (P < 0.05-0.001) after bacteria infusion. In the gilts receiving bacteria, progesterone concentration decreased from day 8 after treatment and was low until the end of the study (P < 0.05-0.001). On days 8-12 after bacteria administration, the level of PGFM was higher (P < 0.001) than that found in the control group. These results suggest that the developing inflammatory process of the endometrium in gilts following Escherichia coli infusion significantly affects the pituitary-ovarian axis function as well as prostaglandin production leading to anoestrus. uterus / inflammation / LH / progesterone / gilt

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Section: Discussionsupporting

confidence: 49%

Effect of intrauterine infusion of Escherichia coli on hormonal patterns in gilts during the oestrous cycle

2004

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“…In addition, bacterial endotoxins released in the uterus may stimulate cortisol secretion, which in turn suppresses pre-ovulatory surge-like release of LH . In this regard, it has been shown that endotoxin can modulate the pre-ovulatory surge-like release of LH in heifers Peter et al 1990;Peter et al 1991;Suzuki et al 2001) by an unknown mechanism. In short, they (endotoxin and their mediators) can disturb the hormonal interactions that control normal ovarian function (Battaglia et al 2000;Williams et al 2001).…”

Section: Predisposing Factorsmentioning

confidence: 99%

An Update on Cystic Ovarian Degeneration in Cattle

Peter

2004

Reprod Domestic Animals

162

145

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Cystic ovarian degeneration (COD) is considered to be one of the most important causes of reproductive failure in cattle. There is a severe economic loss to dairy industry because COD increases days-open in the postpartum period and the culling rates. The disease process is a consequence of a mature follicle that fails to ovulate at the appointed time of ovulation in the oestrous cycle. This anovulatory follicular structure either regresses or persists as a follicular or luteal cyst depending upon its structural/functional characteristics. The cells lining the follicular cyst synthesize oestrogen that, in certain instances, forces the animal to exhibit clinical signs of nymphomania. Besides oestrogen production, as per recent findings, they are also capable of secreting varying amount of progesterone which may dictate their fate. The animals that carry a luteal cyst may tend to be in anoestrus as the higher amount of progesterone secreted by this luteinized structure may change the pattern of gonadotrophins' secretion. Present findings suggest that perturbation of the hypothalamo-hypophyseal-ovarian (HHO) axis, due to many exogenous and endogenous factors, as the cause for anovulation. For example, it has been suggested that lack of hypothalamic or hypophyseal response to the positive feedback effect of oestrogens that are secreted by the dominant follicle as one of the many causes. The non-physiological changes that occur in the receptor expression of the HHO axis for the hormones involved in maturation, deviation, dominance and ovulation of the follicle may be yet another cause. The changes that occur at the cellular and molecular level in the ovary (in response to the factors mentioned above) that contribute to anovulation remain to be documented. This approach would allow us to completely understand the disease process. Hitherto, hormonal preparations that release luteinizing hormone from the anterior pituitary or have luteinizing hormone-like action are used to treat follicular cysts. GnRH belongs to the former group and human chorionic gonadotrophin (hCG) hormone forms the latter group. Treatment with a luteolytic agent, prostaglandin F2alpha (PGF2alpha), is successful if a luteal cyst is diagnosed properly. Many agents may be developed in the future if the cellular and molecular pathways of the disease process are delineated. This article will review recent advances in our understanding of the pathogenesis of COD and suggest direction for future studies to completely understand the disease mechanism. This review will also discuss the existing method of treatments for cysts and methods proposed for treatment of cysts that tend to be refractory in nature.

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Changes in prostaglandin production and ovarian function in gilts during endometritis induced by Escherichia coli infection

Jana

Kucharski

Dzienis

et al. 2007

Animal Reproduction Science

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Quantification of circulating beta-endorphin and white blood cells in heifers after intrauterine administration of endotoxin

Cited by 4 publications

References 20 publications

Effect of intrauterine infusion of Escherichia coli on hormonal patterns in gilts during the oestrous cycle

Effect of intrauterine infusion of Escherichia coli on hormonal patterns in gilts during the oestrous cycle

An Update on Cystic Ovarian Degeneration in Cattle

Changes in prostaglandin production and ovarian function in gilts during endometritis induced by Escherichia coli infection

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