Eutheria Foundation

Cross Plains, WI, United States

Eutheria Foundation

Cross Plains, WI, United States
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Ginther O.J.,Eutheria Foundation | Ginther O.J.,University of Wisconsin - Madison | Fuenzalida M.J.,Eutheria Foundation | Hannan M.A.,Eutheria Foundation | Beg M.A.,University of Wisconsin - Madison
Biology of Reproduction | Year: 2011

Temporality among episodes of a prostaglandin F2alpha metabolite (PGFM), progesterone (P4), luteinizing hormone (LH), and estradiol (E2) were studied during preluteolysis and luteolysis. A vehicle group (n = 10) and a group with an E2-induced PGFM pulse (n = 10) were used. Blood sampling was done every 0.25 h for 8 h. An episode was identified by comparing its coefficient of variation (CV) with the intra-assay CV. Pulsatility of PGFM, P4, LH, and E2 in individual heifers was inferred if the autocorrelation functions were different (P < 0.05) from zero. About four nonrhythmic fluctuations of PGFM/8 h were superimposed on PGFM pulses. Pulsatility was detected for LH but not for P4 and E2. A transient increase in P4 was not detected during the ascending portion of a PGFM pulse. Progesterone decreased (P< 0.003) during Hours -1.25 to -0.50 of the PGFM pulse (Hour 0=peak) and ceased to decrease temporally with an increase (P < 0.05) in LH. Maximum P4 concentration occurred 0.25 h after an LH pulse peak, and an increase (P< 0.005) in E2 began at the LH peak. Nadirs of LH pulses were greater (P < 0.05) and the nadir-to-nadir interval was shorter (P < 0.003) in the E2 group, which is consistent with reported characteristics during luteolysis. The results did not support the hypothesis of a transient P4 increase early in a PGFM pulse and indicated a balance between a luteolytic effect of PGF and a luteotropic effect of LH within the hours of a PGFM pulse. © 2011 by the Society for the Study of Reproduction, Inc.


Ginther O.J.,Eutheria Foundation | Ginther O.J.,University of Wisconsin - Madison | Rakesh H.B.,Eutheria Foundation | Hoffman M.M.,Eutheria Foundation
Theriogenology | Year: 2014

The diameter of the dominant follicle (DF) of wave 1 was studied on Days 9 to 17 (Day 0 = ovulation) in a survey of the ipsilateral and contralateral relationships between the location of the DF and CL, and number of follicular waves per interovulatory interval (IOI). For contralateral relationships, regardless of number of waves the diameter of the DF of wave 1 decreased (P < 0.03) between Days 11 and 13 when referenced to the follicle-CL relationship of wave 1 and decreased (P < 0.008) between Days 9 and 11 when referenced to the preovulatory follicle (PF)-CL relationship. For wave 2 in two-wave IOIs, the CL ovary of ipsilateral relationships had more (P < 0.05) follicles that reached at least 6 mm than the non-CL ovary. In three-wave IOIs, frequency of IOIs with the DF in the CL ovary was greater (P < 0.02) for wave 2 than for wave 3. In wave 3, the preovulatory and the largest subordinate follicles were located more frequently (P < 0.005) in the contralateral ovary. Ovulation in two-wave IOIs occurred more frequently (P < 0.0009) from the right ovary. In three-wave IOIs with a contralateral relationship ovulation occurred more frequently (P < 0.003) from the left ovary; a negative intraovarian effect of the CL on location of the PF may account for more ovulations from the left ovary and a reported greater frequency of the contralateral relationship. The hypothesis was supported that the ipsilateral versus contralateral relationship between the PF and CL is affected by the DF-CL relationship during the previous follicular waves and by the number and identity of waves per IOI. © 2014 Elsevier Inc.


Ginther O.J.,Eutheria Foundation | Ginther O.J.,University of Wisconsin - Madison
Theriogenology | Year: 2014

Gray-scale ultrasonic imaging (UI) was introduced in 1980 and initially was used to examine clinically the reproductive tract of mares. By 1983 in mares and 1984 in heifers/cows, UI had become a tool for basic research. In each species, transrectal gray-scale UI has been used extensively to characterize follicle dynamics and investigate the gonadotropic control and hormonal role of the follicles. However, the use of transrectal UI has also disclosed and characterized many other aspects of reproduction in each species, including (1) endometrial echotexture as a biological indicator of circulating estradiol concentrations, (2) relative location of the genital tubercle for fetal gender diagnosis by Days 50 to 60, and (3) timing of follicle evacuation during ovulation. Discoveries in mares include (1) embryo mobility wherein the spherical conceptus (6-16 mm) travels to all parts of the uterus on Days 11 to 15, (2) how one embryo of a twin set eliminates the other without self-inflicted damage, and (3) serration of the granulosum of the preovulatory follicle opposite to the future rupture site as an indicator of imminent ovulation. Studies with color-Doppler UI have shown that vascular perfusion of the endometrium follows the equine embryo back and forth between uterine horns and follows the expansion of the bovine allantochorion throughout each horn. In heifers, blood flow in the CL increases during the ascending portion of an individual pulse of PGF2α metabolite and then decreases. These examples highlight the power of UI in reproduction research. Without UI, it is likely that these and many other findings would still be unknown. © 2014 Elsevier Inc.


Ginther O.J.,Eutheria Foundation | Ginther O.J.,University of Wisconsin - Madison | Beg M.A.,University of Wisconsin - Madison
Animal Reproduction Science | Year: 2011

The temporal associations of cortisol, estradiol-17β, and oxytocin with pulses of PGFM at the common hour of transition between preluteolysis and luteolysis was studied in plasma from hourly blood samples in mares (n=8). The transitional hour was determined from progesterone concentrations and occurred between 2. PM and 2. AM in all mares. Pulses of PGFM were grouped into those occurring at the last pulse of preluteolysis (preluteolytic pulse), at the hour of transition (transitional), and during luteolysis (luteolytic). The preluteolytic PGFM pulse (45±16. pg/ml at peak) and transitional pulse (42±7. pg/ml) are reportedly less prominent than the first luteolytic pulse (193±36. pg/ml). Cortisol increased (P<0.05) between -1. h and 0. h (peak) and then decreased (P<0.05) within the hours of the luteolytic PGFM pulse but did not change within the preluteolytic and transitional pulses. Estradiol increased (P<0.006) during -3 to 2. h of the luteolytic pulse but not for the other pulses. Oxytocin differed for the hours of the transitional PGFM pulse (P<0.02) and the luteolytic pulse (P<0.03) but did not differ significantly during the hours of the last preluteolytic pulse. Oxytocin increased (P<0.05) between -3. h and 0. h and then decreased (P<0.05) within each of the transitional and the luteolytic pulses. The oxytocin results are novel and support the hypothesis that on a temporal basis oxytocin in association with PGF2α accounts for the transition between preluteolysis and luteolysis within a single hour in mares, despite the small transitional PGFM pulse. © 2011 Elsevier B.V.


Ginther O.J.,Eutheria Foundation | Ginther O.J.,University of Wisconsin - Madison | Beg M.A.,University of Wisconsin - Madison
Animal Reproduction Science | Year: 2011

Pulses of prolactin (PRL) and a metabolite of prostaglandin F2α (PGFM) were determined from hourly blood samples collected before, during, and after luteolysis (. n=. 7 heifers). Progesterone concentrations were used to partition the results into six 12-h sets from 12. h before to 36. h after luteolysis. Pulses of PRL with a nadir-to-nadir interval of 4.4. ±. 0.2. h were detected in each 12-h set. Pulses were rhythmic (. P<. 0.05) in six heifers, beginning 12. h before the end of luteolysis. The peak of a PRL pulse was greater (. P<. 0.05) for the 12. h after the end of luteolysis than for other 12-h sets, except for the last set of luteolysis. Area under the curve of a pulse was greater (. P<. 0.05) for the 24. h that encompassed the end of luteolysis than for two previous 12-h sets. Synchrony between the peaks of PRL and PGFM pulses was greater (. P<. 0.03) during and after luteolysis (same hour for 29/39 pairs) than before luteolysis (0/12). Concentration of PRL centralized to the peak (Hour 0) of PGFM pulses was greater (. P<. 0.05) at Hours 0 and 1 than at Hours -2, -1, and 3. Results supported the hypothesis that PRL is secreted in pulses in heifers. The pulses were most prominent and rhythmic during the last 12. h of luteolysis and thereafter. The pulse peaks of PRL and PGFM were synchronized for most PRL pulses during and after luteolysis. © 2011 Elsevier B.V.


Ginther O.J.,Eutheria Foundation | Ginther O.J.,University of Wisconsin - Madison | Bashir S.T.,Eutheria Foundation
Theriogenology | Year: 2013

In Survey 1, the records for 196 interovulatory intervals (IOIs) from 24 heifers were used to study the frequency and repeatability for number of follicular waves per IOI and to study the ipsilateral and contralateral relationships between the extant corpus luteum and ovulatory follicle. In Survey 2, 96 IOIs were used from the controls of the previous experiments that included the day of the end of the luteolytic period (progesterone <1.0ng/mL). In Survey 1, the percentage of two-wave IOIs (63%) was greater (P < 0.0002) than for three-wave IOIs (37%). The percentage of ovulatory periods with a contralateral relationship (59%) was greater (P < 0.003) than with the ipsilateral relationship (41%). There were more repeats (66%) than reverses (34%) between adjacent IOIs in number of waves per IOI (P < 0.004), but there was no difference in number of corpus luteum/follicle relationships between the ovulatory periods at the beginning and end of an IOI. For the four permutations of ipsilateral and two waves, contralateral and two waves, ipsilateral and three waves, and contralateral and three waves in Survey 2, the interval (days) from ovulation to the day the progesterone was <1.0 ng/mL was 17.8 ± 0.2a, 17.6 ± 0.2a, 20.0 ± 0.3b, and 21.4 ± 0.3c, respectively, and the number of IOIs was 33 (34%)a, 34 (35%)a, 8 (8%)b, and 22 (23%)a, respectively; means with different superscripts are different (P<0.05). The luteal phase was longer for the contralateral relationship than for the ipsilateral relationship for three-wave IOIs but not for two-wave IOIs. The hypothesis was supported that the frequency of the ipsilateral and three-wave permutation was less than for each of the other three permutations. © 2013 Elsevier Inc.


Ginther O.J.,Eutheria Foundation | Ginther O.J.,University of Wisconsin - Madison | Santos V.G.,Eutheria Foundation | Mir R.A.,Eutheria Foundation | Beg M.A.,University of Wisconsin - Madison
Theriogenology | Year: 2013

Three studies were done on the effects of ipsilateral location (same ovary) versus contralateral location (opposite ovaries) of the future ovulatory follicle and CL in heifers. The numbers of heifers for the ipsilateral and contralateral groups, respectively, were: experiment (Exp) 1 (N = 4 and 4), Exp 2 (N = 6 and 4), and Exp 3 (N = 5 and 10). In the Exps with available data (Exp 2 and 3), the interval between ovulation and the end of luteolysis was significantly shorter in the ipsilateral group than in the contralateral group (Exp 2: 16.8 ± 0.3 vs. 19.8 ± 1.7 days; Exp 3: 16.9 ± 0.2 vs. 19.7 ± 0.9 days). In Exp 3, the interovulatory interval was shorter (P < 0.01) in the ipsilateral group (20.1 ± 0.4 days) than in the contralateral group (22.7 ± 0.7 days), but the interval from the end of luteolysis to ovulation was not altered significantly. Circulating progesterone (P4) concentration for 33 hours normalized to the beginning of luteolysis (Exp 1) and on Days 16 to 20 (Day 0 = ovulation; Exp 3) was significantly lower in the ipsilateral group than in the contralateral group (Exp 1: 3.7 ± 0.2 vs. 4.8 ± 0.3 ng/mL; Exp 3: 1.7 ± 0.4 vs. 5.9 ± 0.4 ng/mL). Area (cm2) of the CL and percentage of CL with color Doppler signals of blood flow were lower and resistance index for a CL arteriole was greater in the ipsilateral group (Exp 3). The decreased P4 concentration in the ipsilateral group began by Day 16, but the decreased luteal area and vascular perfusion were not detected until Days 17 or 18. Results supported the hypothesis that the ipsilateral location of the future ovulatory follicle and CL was associated with lower P4 production and a shorter interovulatory interval. © 2013 Elsevier Inc.


Ginther O.J.,Eutheria Foundation | Ginther O.J.,University of Wisconsin - Madison
Theriogenology | Year: 2012

The mare is a good comparative model for study of ovarian follicles in women, owing to striking similarities in follicular waves and the mechanism for selection of a dominant follicle. Commonality in follicle dynamics between mares and women include: (1) a ratio of 2.2:1 (mare:woman) in diameter of the largest follicle at wave emergence when the wave-stimulating FSH surge reaches maximum, in diameter increase of the two largest follicles between emergence and the beginning of deviation between the future dominant and subordinate follicles, in diameter of each of the two largest follicles at the beginning of deviation, and in maximum diameter of the preovulatory follicle; (2) emergence of the future ovulatory follicle before the largest subordinate follicle; (3) a mean interval of 1 day between emergence of individual follicles of the wave; (4) percentage increase in diameter of follicles for the 3 days before deviation; (5) deviation 3 or 4 days after emergence; (6) 25% incidence of a major anovulatory follicular wave emerging before the ovulatory wave; (7) 40% incidence of a predeviation follicle preceding the ovulatory wave; (8) small but significant increase in estradiol and LH before deviation; (9) cooperative roles of FSH and insulin-like growth factor 1 and its proteases in the deviation process; (10) age-related effects on the follicles and oocytes; (11) approximate 37-hour interval between administration of hCG and ovulation; and (12) similar gray-scale and color-Doppler ultrasound changes in the preovulatory follicle. In conclusion, the mare may be the premier nonprimate model for study of follicle dynamics in women. © 2012 Elsevier Inc..


Ginther O.J.,Eutheria Foundation | Ginther O.J.,University of Wisconsin - Madison
Theriogenology | Year: 2012

Recent findings on the luteolytic process in mares are reviewed and differences from other farm species are noted. It is well known that the luteolysin, PGF2α (PGF), is secreted from the endometrium in the absence of pregnancy in farm animal species. But PGF is a potent chemical and safeguards have evolved so that only the corpus luteum (CL) is affected. The safeguards include a short PGF half-life and secretion in two or three pulses per day. In mares, endogenous PGF travels from the uterus to the CL through the systemic circulation, but the luteal-cell membranes are highly efficient in capturing the PGF molecules. In ruminants, luteal affinity is lower, but an efficient pathway has evolved for local delivery of PGF from a uterine horn to the adjacent ovary. The beginning of transition from luteal control is manifested within 1 h in mares and heifers, as indicated by a dynamic change in systemic progesterone concentrations. In mares, the transition into luteolysis begins during a relatively small transitional pulse of PGFM (a PGF metabolite) and oxytocin increases with the PGFM pulse. During luteolysis, estradiol increases in stepwise fashion within the hours of each PGFM pulse, with a plateau between pulses. Progesterone decreases linearly within the hours of a PGFM pulse and continuing during the interval between pulses, whereas luteal blood flow decreases during the declining portion of the pulse. In contrast, in heifers, progesterone decreases and increases within the hours of a PGFM pulse, and luteal blood flow increases and decreases concomitantly with the pulse. © 2012 Elsevier Inc.


Ginther O.J.,Eutheria Foundation | Ginther O.J.,University of Wisconsin - Madison | Beg M.A.,University of Wisconsin - Madison
Theriogenology | Year: 2012

Hourly blood sampling in both horses and cattle indicate that the transition between the end of preluteolysis and the beginning of luteolysis occurs within 1 h, as manifested by a change in progesterone concentrations. Each species presents a separate temporality enigma on the relationship between pulses of a prostaglandin (PG) F2α metabolite (PGFM) and the hour of the progesterone transition. In horses, relatively small pulses of PGFM occur during preluteolysis (before transition) and at transition. Oxytocin, but not estradiol, increases and decreases concomitantly with the small PGFM pulse at transition but not with previous pulses and may account for the initiation of luteolysis during the small PGFM pulse. In cattle, the last PGFM pulse of preluteolysis occurs hours before transition (e.g., 4 h), and the next pulse occurs well after transition (e.g., 9 h); unlike in horses, a PGFM pulse does not occur at transition. During the last PGFM pulse before transition, progesterone concentration decreases during the ascending portion of the PGFM pulse. Concentration then rebounds in synchrony with an LH pulse. The rebound returns progesterone to the concentration before the PGFM pulse. During luteolysis, an LH-stimulated progesterone rebound may occur after the peak of a PGFM pulse, but progesterone does not return to the concentration before the PGFM pulse. A similar LH-stimulated progesterone rebound does not occur in horses, and therefore progesterone fluctuations are more shallow in horses than in cattle. © 2012 Elsevier Inc.

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