Suppression of luteal function in dogs by luteinizing hormone antiserum and by bromocriptine

Concannon, Patrick W.; Weinstein, P.; Whaley, Sandra L.; Frank, Doyle

doi:10.1530/jrf.0.0810175

Cited by 78 publications

(61 citation statements)

References 18 publications

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“…This suggests that not LH but PRL is closely involved in stimulation of the corpus luteum 25 days after ovulation. This result supports the finding that PRL is a luteotrophic factor in dogs [3,19,21,23].…”

Section: Discussionsupporting

confidence: 92%

Influence of a PGF2.ALPHA.-Analogue, Etiproston Tromethamine, on the Functional Corpus Luteum of Dogs

Kirihara

Naganawa

Hori

et al. 2005

The Journal of Veterinary Medical Science

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ABSTRACT. To induce luteal regression-related abortion/delivery and treat pyometra in dogs, various PGF 2α -analogues (PGAs) are administered, but a PGA most appropriate for clinical application in dogs, with a low incidence of side effects, is being investigated. In this study, we compared the effects of etiproston tromethamine (PGA-E), which has not been investigated in dogs, with those of cloprostenol (PGA-C), which is routinely used in dogs. A single dose of PGA-E at 100, 200, 400 or 800 µg or PGA-C at 12.5, 25, 50 or 100 µg was administered to beagles (n=5 per group) 25 days after ovulation, when the corpus luteum was in the functional phase. We compared the state of luteal regression by measuring plasma progesterone levels. As side effects, the incidences of salivation, vomiting, tachypnea, diarrhea and the drop in body temperature were investigated. In the 400-µg and 800-µg groups treated with PGA-E, the mean intervals from administration until luteal regression were 18.6 days and 31.2 days, respectively. In the dogs treated with 50 µg or more of PGA-C, luteal regression was noted 2 days after administration. The above side effects were observed for 3 hr after administration of PGA-E/PGA-C. In the dogs treated with 800 µg of PGA-E, the mean body temperature was 36.7°C 4 hr after administration; hypothermia persisted. PGA-E may be less useful than PGA-C for promoting luteal regression in dogs in clinical application.

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Section: Discussionsupporting

confidence: 92%

Influence of a PGF2.ALPHA.-Analogue, Etiproston Tromethamine, on the Functional Corpus Luteum of Dogs

Kirihara

Naganawa

Hori

et al. 2005

The Journal of Veterinary Medical Science

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“…Douglas et al [8] reported that prolactin and luteinizing hormone (LH) are necessary for maintenance of the corpus luteum during postimplantation gestation in mink. Normal luteal function in dogs also requires both prolactin and LH [5,6]. Further studies are required to clarify the immediate trigger of abortion during the active pregnancy period in pinnipeds.…”

Section: Discussionmentioning

confidence: 99%

Immunohistochemical Localization of Steroidogenic Enzymes in the Corpus Luteum and the Placenta of the Ribbon Seal(Phoca fasciata) and Steller Sea Lion.

Ishinazaka

Suzuki

Yamamoto

et al. 2001

The Journal of Veterinary Medical Science

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ABSTRACT. To study the luteal and placental function of pinnipeds, we analyzed the localization of steroidogenic enzymes (P450scc, 3 β HSD and P450arom) in the corpus luteum and the placenta of ribbon seals (Phoca fasciata) and Steller sea lions (Eumetopias jubatus) immunohistochemically. P450scc and 3 β HSD were present in all luteal cells of both species. Almost all of the luteal cells were immunostained for P450arom, while P450scc and 3 β HSD were negatively immunostained in placentae and P450arom was present in the syncytiotrophoblast of placentae. These findings suggest that 1) corpora lutea of both species synthesize pregnenolone, progesterone and estrogen during the entire pregnancy period, and 2) like other terrestrial carnivores in the suborder Caniformia, placentae of both species do not have the capability for synthesizing progesterone in the latter half of active pregnancy period. KEY WORDS: corpus luteum, placenta, ribbon seal, Steller sea lion, steroidogenic enzyme.J. Vet. Med. Sci. 63(9): 955-959, 2001 Both the ribbon seal (Phoca fasciata) and the Steller sea lion (Eumetopias jubatus) are highly adapted for an aquatic lifestyle, and they are classified in the order Carnivora [13,20]. In the past, seals (family Phocidae), sea lions (family Otariidae) and walrus (family Odobenidae) were usually classified as a separate order, the Pinnipedia, or as a suborder of the order Carnivora. However, many morphological and molecular studies have recently revealed that affinities of the Pinnipedia lie within the suborder Caniformia of the order Carnivora, which includes Ursidae (bears) and Mustelidae (weasels, martens, etc.) [20].From the viewpoint of reproduction, delayed implantation occurs in most pinnipeds as it does in bears and martens [1,16,17]. Although the total pregnancy periods of ribbon seals and Steller sea lions last almost one year, their postimplantation periods (active pregnancy periods) are shorter due to delayed implantations [14]. Timing of implantation in ribbon seals is assumed to occur in August [2], although details are unknown. The attachment of blastocyst in Steller sea lions occurs in late September and October [19]. The peak of pupping of ribbon seals and Steller sea lions occurs early in April and early in June, respectively [3,19].In some terrestrial carnivorous animals, the corpus luteum is the most important source of progesterone during the entire gestation period [6,8,18,22,23]. In seals, however, it is not known whether the corpus luteum can synthesize progesterone in late pregnancy, or if the placenta replaces the corpus luteum as a principal source of progesterone, as occurs in sheep and humans [18]. The aim of this study is to clarify whether the corpus luteum and the placenta of ribbon seals and Steller sea lions in the latter half of an active pregnancy period are capable of steroidogenesis. MATERIALS AND METHODSOvaries and placentae were collected from 8 wild ribbon seals and 8 wild Steller sea lions. The animals were shot legally by hunters as part of nuisance contr...

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“…The canine luteal phase can be divided into two periods: i) the early luteal phase, lasting 2-4 weeks of steadily increasing P 4 concentrations, highest proliferation rate and resistance to luteolytic treatments that are effective later in the cycle (Okkens et al 1986, Concannon et al 1987 and ii) the mature-CL portion of phase, during which the CL is more responsive to luteal treatments. Both LH and prolactin (PRL) are luteotrophic (Concannon 1980, Onclin et al 2000.…”

Section: Introductionmentioning

confidence: 99%

“…Both LH and prolactin (PRL) are luteotrophic (Concannon 1980, Onclin et al 2000. For the mature CL in the second half of dioestrus, PRL becomes the main luteotrophic hormone (Concannon et al 1987, Okkens et al 1990, blocking LH function, however, results only in a transient P 4 decrease (Concannon et al 1987, Onclin et al 2000. Luteal regression, however, is unavoidable and occurs in spite of an increased gonadotrophic support.…”

Section: Introductionmentioning

confidence: 99%

Prostaglandin E2 functions as a luteotrophic factor in the dog

Kowalewski¹,

Fox²,

Gram³

et al. 2013

Reproduction

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The luteal phase in dogs is governed by many poorly understood regulatory mechanisms. Functioning of the corpus luteum (CL) is unaffected by hysterectomy. Recently, the role of prostaglandins in regulating canine CL function was addressed suggesting a luteotrophic effect of prostaglandin E 2 (PGE 2 ) during the early luteal phase. However, compelling functional evidence was lacking. The potential of PGE 2 to stimulate steroidogenesis was tested in canine primary luteal cells isolated from developing CL of non-pregnant dogs. In addition, the luteal expression of prostaglandin transporter (PGT) and steroidogenic acute regulatory protein (STAR) was demonstrated and characterized in CL from non-pregnant bitches during the course of dioestrus as well as from pregnant animals during the preimplantation, post-implantation and mid-gestation periods of pregnancy and during luteolysis; the luteal expression of PGE 2 receptors (EP2 and EP4) has been investigated at the protein level throughout pregnancy. Our findings show that PGE 2 is an activator of STAR expression in canine luteal cells from early luteal phase, significantly up-regulating STAR promoter activity and protein expression resulting in increased steroidogenesis. The 3bHSD (HSD3B2) and P450scc (CYP11A1) expression remained unaffected by PGE 2 treatment. The expression of PGT was confirmed in CL during both pregnancy and dioestrus and generally localized to the luteal cells. After initial up-regulation during the earlier stages of the CL phase, its expression declined towards the luteal regression. Together with the demonstration of EP2 and EP4 throughout pregnancy, and the decline in EP2 at prepartum, our findings further support our hypothesis that intra-luteal PGE 2 may play an important role in regulating progesterone secretion in the canine CL.

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Suppression of luteal function in dogs by luteinizing hormone antiserum and by bromocriptine

Abstract: Summary. Beagle bitches were treated with equine anti-LH serum (ALHS)

Cited by 78 publications

References 18 publications

Influence of a PGF2.ALPHA.-Analogue, Etiproston Tromethamine, on the Functional Corpus Luteum of Dogs

Influence of a PGF2.ALPHA.-Analogue, Etiproston Tromethamine, on the Functional Corpus Luteum of Dogs

Immunohistochemical Localization of Steroidogenic Enzymes in the Corpus Luteum and the Placenta of the Ribbon Seal(Phoca fasciata) and Steller Sea Lion.

Prostaglandin E2 functions as a luteotrophic factor in the dog

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