Effect of Oxytocin Administration on the Oestrous Cycle of Unilaterally Hysterectomized Heifers

Ginther, O.J.; Woody, C. O.; Mahajan, Sudha; Janakiraman, K; Casida, L. E.

doi:10.1530/jrf.0.0140225

Cited by 53 publications

(17 citation statements)

References 5 publications

(5 reference statements)

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“…The ipsilateral i.u. route of PGF administration was used, owing to the natural unilateral delivery of PGF between a uterine horn and the CL in the adjacent ovary in cattle (Ginther et al 1967(Ginther et al , 2009a. The procedures for placement of tubing for infusion of the PGF and for the bolus i.u.…”

Section: Heifers and Treatmentsmentioning

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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Section: Heifers and Treatmentsmentioning

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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“…The minimal effective intrauterine (IU) dose of PGF (1-2 mg [6]) when given into the uterine horn ipsilateral to the corpus luteum (CL) in cattle is about one tenth of the minimal systemic dose (15 mg [7]). The IU effectiveness in cattle results from a unilateral utero-ovarian pathway [8,9]. Surgical anastomoses of the uterine vein or the ovarian artery ipsilateral of an intact uterine horn to the corresponding vessel on the unilaterally hysterectomized side have demonstrated that a venoarterial unilateral pathway adequately accounts for the local luteolytic effect of a uterine horn on the CL in the adjacent ovary [10].…”

Section: Introductionmentioning

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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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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“…The intrauterine effectiveness results from a unilateral utero-ovarian luteolytic pathway in cattle [12,13]; the PGF is transferred into the ovarian artery after intrauterine administration [14] through a local venoarterial pathway between the utero-ovarian vein and the ovarian artery [15].…”

Section: Introductionmentioning

confidence: 99%

Temporal Associations among Pulses of 13,14-Dihydro-15-keto-PGF2alpha, Luteal Blood Flow, and Luteolysis in Cattle1

Ginther

Silva²,

Araújo³

et al. 2007

Biology of Reproduction

140

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Luteal blood flow was studied in heifers by transrectal color-Doppler ultrasound. Data were normalized to the decrease in plasma progesterone to <1 ng/ml (Day 0 or Hour 0). Blood flow in the corpus luteum (CL) was estimated by the percentage of CL area with color flow signals. Systemic prostaglandin F2alpha (PGF) treatment (25 mg; n=4) resulted in a transient increase in CL blood flow during the initial portion of the induced decrease in progesterone. Intrauterine treatment (1 or 2 mg) was done to preclude hypothetical secondary effects of systemic treatment. Heifers were grouped into responders (luteolysis; n=3) and nonresponders (n=5). Blood flow increased transiently in both groups; induction of increased blood flow did not assure the occurrence of luteolysis. A transient increase in CL blood flow was not detected in association with spontaneous luteolysis when examinations were done every 12 h (n=6) or 24 h (n=10). The role of PGF pulses was studied by examinations every hour during a 12-h window each day during expected spontaneous luteolysis. At least one pulse of 13,14-dihydro-15-keto-PGF2alpha (PGFM) was identified in each of six heifers during the luteolytic period (Hours -48 to -1). Blood flow increased (P<0.02) during the 3-h ascending portion of the PGFM pulse, remained elevated for 2 h after the PGFM peak, and then decreased (P<0.03) to baseline. Results supported the hypothesis that CL blood flow increased and decreased with individual PGFM pulses during spontaneous luteolysis.

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Effect of Oxytocin Administration on the Oestrous Cycle of Unilaterally Hysterectomized Heifers

Abstract: Summary. The

Cited by 53 publications

References 5 publications

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

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

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

Temporal Associations among Pulses of 13,14-Dihydro-15-keto-PGF2alpha, Luteal Blood Flow, and Luteolysis in Cattle1

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