Studies of prostaglandin F2α in the cow

Lamond, D. R.; Tomlinson, R. V.; Drost, Maarten R.; Henricks, D. M.; Jöchle, W.

doi:10.1016/0090-6980(73)90045-2

Cited by 50 publications

(28 citation statements)

References 12 publications

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“…Simulation of a natural PGFM pulse was not expected, based on a previous study [22] of circulating PGF concentration following IU injection. Doses of PGF were chosen that were expected to be ineffective, borderline, and effective for inducing luteolysis when given as a single IU treatment ipsilateral to the CL [23].…”

Section: Experiments 1: Iu Injectionmentioning

confidence: 97%

“…Concentrations of PGFM were determined for the frequent blood samples collected during the first hour of session 1 and hourly at Hours 0-6 for sessions 1-4. Progesterone was assayed for the samples collected at Minutes 0, 5, 15, 30, and 60 for the first hour of session 1 to determine if the reported immediate posttreatment increase in progesterone [22] occurred in each PGFtreated group. Progesterone was also assayed for samples collected at 6-h intervals during 0-48 h after the beginning of session 1, thereby encompassing all of the four sessions.…”

Section: Experiments 1: Iu Injectionmentioning

confidence: 99%

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Necessity of Sequential Pulses of Prostaglandin F2alpha for Complete Physiologic Luteolysis in Cattle1

Ginther

Araújo

Palhão

et al. 2009

Biology of Reproduction

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The luteolytic effects of exogenous prostaglandin F2alpha (PGF) that did and did not simulate natural 13,14-dihydro-15-keto-PGF (PGFM) pulses were studied during mid-diestrus in 42 Holstein heifers. Plasma concentrations of PGF were assessed by assay of PGFM. In experiment 1, a single intrauterine injection of 4.0 mg of PGF into the uterine horn ipsilateral to the corpus luteum resulted in a precipitous progesterone decline, whereas sequential injections of 0.25 or 1.0 mg every 12 h resulted in a stepwise decrease (P < 0.05) following each injection. A progesterone increase occurred during the first 5 min before the luteolytic decrease but only for the 4.0-mg dose. From the results of experiment 2, a 2-h intrauterine infusion of a total of 0.5 mg of PGF was judged to best simulate a natural PGFM pulse. In experiment 3, simulation of sequential pulses at 12-h intervals resulted in a continuous precipitous decrease in progesterone to <1 ng/ml by the beginning of the fourth simulated pulse. In contrast, a single simulated pulse resulted in a 6-h progesterone decrease to a constant concentration for 3 days after treatment, followed by a return to control concentrations. The mean +/- SEM interval between the pretreatment and posttreatment ovulations was shorter (P < 0.05) in the group with sequential simulated pulses (14 +/- 1 day) than in the group with a single pulse (21 +/- 1 day). Results indicated that excessive PGF doses may stimulate nonphysiologic progesterone responses and supported the hypothesis that sequential PGF pulses are required to stimulate natural luteolysis in cattle.

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Section: Experiments 1: Iu Injectionmentioning

confidence: 97%

Section: Experiments 1: Iu Injectionmentioning

confidence: 99%

Necessity of Sequential Pulses of Prostaglandin F2alpha for Complete Physiologic Luteolysis in Cattle1

Ginther

Araújo

Palhão

et al. 2009

Biology of Reproduction

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“…Several PGFM pulses may occur each day, and each pulse is several hours in duration. A dose of PGF or a PGF analogue that induces complete luteolysis with a single treatment causes an immediate transient increase in progesterone prior to the decrease (Lamond et al 1973, Hixon & Hansel 1974, Skarzynski et al 2003. The transient increase is reportedly a non-physiologic response to a pharmacologic dose of PGF in heifers (Ginther et al 2009a, Shrestha et al 2010 and mares (Ginther et al 2007a(Ginther et al , 2009c.…”

Section: Introductionmentioning

confidence: 99%

Luteal blood flow and concentrations of circulating progesterone and other hormones associated with a simulated pulse of 13,14-dihydro-15-keto-prostaglandin F2α in heifers

Shrestha¹,

Beg²,

Imam³

et al. 2010

Reproduction

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Progesterone and luteal blood flow effects of an i.u. 2-h infusion of 0.25 mg/h of prostaglandin F 2a (PGF) that simulated a natural pulse of 13,14-dihydro-15-keto-PGF (PGFM) were compared to the effects of a single bolus i.u. injection of PGF (4 mg) that induced complete luteolysis in heifers. Blood sampling and an estimate of the percentage of luteal area with colour-Doppler signals of blood flow were performed every 2 min for 20 min and less frequently thereafter for 6 h. After the beginning of PGF infusion or a bolus injection, progesterone increased to a peak at 14 and 10 min respectively, and was accompanied by an increase in blood flow in the bolus group but not in the infusion group. Progesterone then decreased for 1 or 2 h and was accompanied by a continued elevation in blood flow in the PGF bolus group and by a slight increase in the PGF infusion group. Progesterone then rebounded in both groups, but the rebound was greater in the infusion group. Blood flow decreased during the descending arm of the progesterone rebound. Cortisol and prolactin began to increase 6 min after the bolus PGF injection but did not increase during or after PGF infusion. The increases in cortisol, prolactin and blood flow after a PGF bolus treatment but not during a simulated PGFM pulse indicated that the bolus treatment was pharmacologic, and its use may lead to faulty conclusions on the nature of physiologic luteolysis. The comparisons between progesterone and blood flow are novel.

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“…The luteolytic effect of prostaglandins during pregnancy results in abortion (Lamond et al, 1973;Aboul-Fadle et al, 1975;Sloan, 1976). …”

Section: Induction Of Abortionmentioning

confidence: 98%

“…At the end of pregnancy, their secretion is simultaneous with the fal: in progesterone (Fairclough et al, 1975), although it starts earlier (Edqvist et al, 1975). The administration of PGF 2a Or of an analogue of PGF 2a (A-PGF) is also followed by a fall in the maternal level of progesterone (Lamond et al, 1973;Aboul-Fadle et al, 1975;Bosc et al, 1975;.…”

Section: Control Of Calving With Prostaglandinsmentioning

confidence: 99%