Effect of 17β-estradiol on the preovulatory surge of LH in the bovine female

Stumpf, T. T.; Wolfe, Michael W.; Day, M. L.; Stotts, J. A.; Wolfe, Pamela; Kittok, R. J.; Kinder, J. E.

doi:10.1016/0093-691x(91)90379-r

Cited by 20 publications

(10 citation statements)

References 25 publications

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“…In normal cows, an elevated circulating concentration of estradiol induces the preovulatory LH surge via positive feedback effects in the hypothalamus and pituitary [15].…”

mentioning

confidence: 99%

Changes of Ovarian Structures, Plasma LH, FSH, Progesterone and Estradiol-17.BETA. in a Cow with Ovarian Cysts Showing Spontaneous Recovery and Relapse.

Yoshioka

Iwamura

Kamomae

1998

The Journal of Veterinary Medical Science

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ABSTRACT. In a cow diagnosed as having ovarian cysts, we observed changes in the ovarian structures by ultrasonography for 71 days and examined plasma concentrations of sex hormones. The cow had 2 regressing cysts at the start of this study and 3 new follicles subsequently developed into cysts. With regression of these cysts, 2 new follicles developed and ovulated spontaneously, followed by the formation of 2 corpora lutea. On the day prior to ovulation, a preovulatory luteinizing hormone (LH) surge was detected. With regression of the corpora lutea, a new follicle developed and underwent atresia. Meantime, another follicle developed and became a cyst without ovulation. No preovulatory LH surge was observed during the period from regression of the corpora lutea to cyst formation. The results indicate that absence of the preovulatory LH surge is associated with occurrence of ovarian cysts and this endocrine aberration is reversible. -KEY WORDS: cattle, LH surge, ovarian cyst.J. Vet. Med. Sci. 60(2): 257-260, 1998 Follicular and luteal structures were examined by transrectal ultrasonography using a 5 MHz transducer and linear-array ultrasound scanner (SSD-280, Aloka, Tokyo, Japan) by the method previously described by Pierson and Ginther [13], and rectal palpation was performed to monitor ovarian changes. At each examination, follicles with a diameter exceeding 10 mm and the location of each structure were recorded on an ovarian map. Ultrasonic examination was made at 3 day intervals. When the cysts or corpora lutea regressed, however, and new follicular structures grew from 10 mm to more than 25 mm in diameter or to ovulation, examination was made daily for 2 series.Blood samples were collected by jugular venipuncture into heparinized vacutainers at 2 day intervals following the start of ultrasonic examination. An indwelling jugular cannula was used for sampling, when the ovaries were examined daily. All samples were collected between 8:00 and 9:30 hr. The samples were kept on ice and centrifuged at 1,500 g for 30 min at 4°C within 30 min. Plasma was collected and stored at 20°C until the concentrations of LH, follicle-stimulating hormone (FSH), progesterone and estradiol-17β were measured. Additional blood samples were collected via the jugular cannula into plain vacutainers at 3 hr intervals following the start of daily examinations of the ovaries to determine the presence of a preovulatory LH surge. After collection, the samples were kept for 6-18 hr at room temperature. Serum was separated by centrifugation and stored at 20°C until the concentrations of LH were measured.Plasma and serum concentrations of LH were measured by the homologous double-antibody radioimmunoassay (RIA) method described previously [8] using anti-bovine LH serum (i555/001, UCB-Bioproducts, Braine-l'Alleud, Belgium), bovine LH (i055, UCB-Bioproducts) for radioiodination, and LER-1716-2 (provided by Dr. L. E. Reichert, Albany Medical College) as a reference standard. Plasma concentrations of FSH were measured by RIA [2] using anti-bovi...

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“…In normal cows, an elevated circulating concentration of estradiol induces the preovulatory LH surge via positive feedback effects in the hypothalamus and pituitary [15].…”

mentioning

confidence: 99%

Changes of Ovarian Structures, Plasma LH, FSH, Progesterone and Estradiol-17.BETA. in a Cow with Ovarian Cysts Showing Spontaneous Recovery and Relapse.

Yoshioka

Iwamura

Kamomae

1998

The Journal of Veterinary Medical Science

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“…Ovulation normally follows the preovulatory surge of gonadotropins. This surge is induced by the action of increased peripheral concentrations of estradiol-173 acting on the hypothalamus, which cause a sustained elevation of LHRH in the hypophyseal portal blood [20,21].…”

Section: Discussionmentioning

confidence: 99%

Changes in Ovarian Function and Gonadotropin Secretion Preceding the Onset of Nutritionally Induced Anestrus in Bos indicus Heifers1

Rhodes

Entwistle

Kinder

1996

Biology of Reproduction

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The aim of this study was to monitor endocrine and ovarian changes immediately preceding the onset of nutritionally induced anestrus. Daily blood samples were obtained from 14 postpubertal heifers for one estrous cycle (initial estrous cycle). Subsequently, heifers designated "restricted" were given a limited diet (n = 9), and daily blood samples were obtained for approximately 21 days preceding onset of anestrus (anovulatory cycle). Controls were allowed ad libitum dietary intake (n = 5), and daily blood samples were collected for a complete estrous cycle during a time period that coincided with that preceding onset of anestrus in restricted heifers. Plasma samples were assayed for LH, FSH, progesterone, and estradiol-17 beta. The ovaries of all heifers were examined daily using transrectal ultrasonography from the initial until the final or anovulatory estrous cycles to determine changes in growth of follicles and corpora lutea. Anestrus was defined as failure of ovulation of the dominant follicle following luteolysis. When anovulatory and initial estrous cycles in restricted heifers were compared, mean concentrations of LH were lower (p < 0.01), and diameters of dominant follicles were smaller (p < 0.01); mean concentrations of estradiol-17 beta were also lower in the three days following luteolysis (p = 0.06), but concentrations of FSH appeared to be higher (p = 0.003); maximum diameters of corpora lutea were smaller (p < 0.001), but duration of luteal phases and concentrations of progesterone preceding luteolysis were similar (p > 0.10). In controls, no differences were found between estrous cycles for any of these variables. It is concluded that failure of ovulation, following reduced dietary intake, resulted from insufficient circulating LH to stimulate maturation of the ovulatory follicle.

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“…Bereits zum Zeitpunkt der Luteolyse steigen die LH-Pulsfrequenz und -Konzentration an (48,110). Diese erhöhte LH-Pulsfrequenz ist neben der basalen Progesteronkonzentration Voraussetzung für die Ausbildung des positiven Östrogen-Feedbacks, das den LH-Peak induziert (101,102,111). Während die Östrusdauer -wie bereits erwähnt (ǠTab.…”

Section: Ovulation Ovulationszeitpunkt Und Doppelovulationunclassified

Zyklus hochleistender laktierender Kühe – eine Literaturübersicht

Groeger¹

2010

Tierarztl Prax Ausg G

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Vascularized allotransplantation of knee joints under immunosuppression is a novel approach in orthopedic surgery. During the postoperative course immunosuppressive management depends on perfusion and viability of the graft. Aim: Evaluation of different diagnostic tools in regard to their usefulness and reliability to provide information about microvascularity and viability of vascularized knee joint allografts. Methods: Four patients with allogenic knee joint transplants were studied up to 26 months after transplantation with 3-phase bone scans and SPECT. The results were compared with duplex sonography, angiography, and histology. Results: Two cases without complications were characterized by adequate perfusion in duplex sonography, angiography and early bone scans. Late bone scans demonstrated increased bone metabolism of the transplant. Corresponding biopsy revealed viable bone cells. In one case with partial thrombosis and one case with complete thrombosis of the transplant vessels rapidly decreasing or missing perfusion was detected by duplex sonography, angiography, and bloodpool scintigraphy. Late bone scans showed reduced or absent bone metabolism. Biopsy demonstrated necrotic bone tissue. Due to the advantage of a tomographic technique SPECT allowed a more reliable assessment of graft viability as compared to planar imaging. Conclusion: Our findings confirm bone scintigraphy as a valuable diagnostic tool in patients with allogenic vascularized knee joint transplants. In contrast to other diagnostic approaches, scintigraphy provides reliable information on both viability and perfusion of the transplant within a single noninvasive clinical investigation.

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Effect of 17β-estradiol on the preovulatory surge of LH in the bovine female

Cited by 20 publications

References 25 publications

Changes of Ovarian Structures, Plasma LH, FSH, Progesterone and Estradiol-17.BETA. in a Cow with Ovarian Cysts Showing Spontaneous Recovery and Relapse.

Changes of Ovarian Structures, Plasma LH, FSH, Progesterone and Estradiol-17.BETA. in a Cow with Ovarian Cysts Showing Spontaneous Recovery and Relapse.

Changes in Ovarian Function and Gonadotropin Secretion Preceding the Onset of Nutritionally Induced Anestrus in Bos indicus Heifers1

Zyklus hochleistender laktierender Kühe – eine Literaturübersicht

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