Synchronisation of oestrus in heifers using steroid (SC5914, SC9880 and SC21009) treatment for 21 days: 1. The effect of treatment on pregnancy rate to artificial insemination

SC5914, SC9880 or SC21009 was administered by daily intramuscular injection of 5.4 mg, 2.4 mg or 0.14 mg respectively. Treatment of 90 cyclical Friesian heifers began on day 4, 11 or 18 of the cycle, and continued for 21 days. Twice daily observations for oestrus were made during treatment and for 28 days thereafter. Heifers in oestrus within 5 days of the end of treatment were inseminated. Pregnancy was diagnosed by palpation at 42 days. 88.9% of the heifers treated were in oestrus within 5 days. Treatment had a highly significant effect on fertility. The pregnancy rate for the SC5914, SC9880 and SC21009 groups were 65%, 72% and 36% respectively. The pregnancy rate of 28 untreated control animals inseminated with semen from the same ejaculate as was used in the treated groups was 93%.     

Synchronisation of oestrus in heifers using steroid (SC5914, SC9880 and SC21009) treatment for 21 days: 2. The effect of treatment on the ovum collection and fertilisation rate and the development of the early embryo

150 cyclical Friesian heifers were subjected to surgery under general anaesthesia for the purpose of ovum collection. All had been inseminated with semen from the same ejaculate from a Hereford bull. 50 heifers were in oestrus after daily intramuscular injections of 2.4 mg SC9880 and 50 were in oestrus after similar treatment with 0.2 mg SC21009. The remainder were untreated controls. Equal numbers in each group were subjected to surgery on the third and fourth day after oestrus. An attempt was made to determine whether the collected ova were fertilised; what the cleavage stage was and whether or not gross abnormalities were present. 125 (83.3%) ova were collected. Of these 118 (94.4%) were fertilised. Steroid treatment had no significant effect on ovum collection rate or fertilisation rate or on the incidence of abnormal forms. Treatment significantly affected the cleavage stage of the early embryo. Treatment with both steroids was associated with early cleavage forms which were absent in the untreated animals. The implications of this finding in relation to fertility depression in heifers treated with SC9880 or SC21009 for 21 days is discussed.     

Blood LH after PGF2α in diestrous and ovariectomized cattle

Two experiments were conducted to determine whether the increased serum LH which occurs within 12 hr after a luteolytic dose of PGF_2α is dependent upon changes in progesterone or estradiol secretion. In the first experiment, exogenous progesterone abolished the increase in serum LH caused by a subcutaneous injection of 25 mg PGF_2α in diestrous heifers, but not in ovariectomized heifers. In the second experiment, progesterone pessaries were removed at 6 hr after a subcutaneous injection of 25 mg PGF_2α. LH remained at pre-PGF_2α values while the pessaries were in place, but began to increase within 1 hr after they were removed. Blood estradiol also remained at pre-PGF_2α values until the pessaries were removed, and began to increase at 2 hr after pessary removal. We conclude that the increase in serum LH within 12 hr after PGF_2α treatment in diestrous cattle is dependent upon withdrawal of progesterone; it is not due to increased serum estradiol.     

Evaluation of a new progestin (Sa 45.249) in cattle

Daily oral administration of the progestin Sa 45.249 to 80 cycling heifers, at doses ranging from 6 to 14 mg/day and over varying treatment periods (from 8 to 16 days) resulted in all animals in complete estrus inhibition. Irrespective of the dose and the treatment period used, heat and ovulations — as judged by the corpora lutea which became palpable on day 15 of this cycle — occurred between day 2 and 9 after cessation of treatment in 73 of 80 heifers (91%). Neither the daily dose nor the duration of treatment had any discernible effect on the occurrence of heat.This pattern was confirmed in a pilot field trial. From artificial insemination at the first and second heat after treatment, 16 of 21 treated heifers (76%) and 45 of 55 cows (80%) were pregnant. There was no difference in cyclic plasma progesterone levels between heifers treated for 14 days with 10 mg Sa 45.249 and untreated controls, when treatment commenced either on day 5 or 14 of the cycle, with the exception of the delay in the post-ovulatory rise in the latter treatment.     

Control of oestrus in cattle using progesterone coils

Four experiments were conducted to determine the effect of length of treatment, stage of cycle at start of treatment and administration of oestradiol benzoate or progesterone at the start of treatment with intravaginal progesterone coils on oestrous response and fertility. In Experiment 1, the number of heifers in oestrus was affected neither by injection of 5 mg oestradiol benzoate alone or with 200 mg progesterone nor by length of treatment. More heifers (P < 0.05) were in oestrus on day 2 after treatment following a 12-day treatment compared to a 9-day treatment.In Experiment 2, heifers between days 17 and 20 of the oestrous cycle received an injection of either 5 mg oestradiol benzoate alone or with 200 mg progesterone at the start of a 9-day treatment with progesterone coils. Neither the number of heifers in oestrus nor the pattern of onset were affected after treatment. In Experiment 3, heifers between days 0 and 3 of the oestrus cycle received progesterone coils for 9, 12 or 14 days. In addition, animals received (i) no further treatment, (ii) a gelatin capsule adhered to the coil containing 10 mg oestradiol benzoate (iii) a gelatin capsule adhered to the coil containing 200 mg progesterone. Following a 9- or 12-day treatment period heifers receiving the coil with the oestrogen capsule had a high oestrous response ( compared to , P < 0.05). When oestrogen was not given, there was a significant linear effect of duration of treatment on the number in oestrus (9 days, ; 12 days ; 14 days, ; P < 0.05).In Experiment 4, post-partum cows were used to compare a 9- and 12-day treatment period and half the animals in each group received either 5 mg oestradiol benzoate and 200 mg progesterone at the start of treatment or a 10 mg gelatin capsule adhered to the coil. The length of treatment affected the number of heifers in oestrus since were in oestrus after a 12-day treatment period compared with after a 9-day period (P < 0.001). There were no significant differences in the number of cows in oestrus after injection of oestrogen and progesterone () or after the use of the gelatin capsule ().     

Synchronisation of oestrus in dairy cows using prostaglandin F2alpha,gonadotrophin-releasing hormone,and oestradiol cypionate

An oestrous synchronisation protocol was developed for use in lactating dairy cows using PGF(2alpha), GnRH, and oestradiol cypionate (ECP). In experiment 1, lactating dairy cows received two injections of PGF(2alpha) (on days 0 and 11) (PP; n=10) or two injections of PGF(2alpha) (days 0 and 11) and 100 microg of GnRH on day 3 (PGP; n=10). In experiment 2, cows were treated with PGP (n=7), or PGP and 1 mg of ECP at the same time (PGPE(0); n=7) or 1 day after the second PGF(2alpha) injection (PGPE(1); n=7). In experiment 3, 101 lactating dairy cows in a commercial herd were assigned to one of three treatments; PP, PGP, or PGPE(1). Follicular growth was measured by ultrasound in experiments 1 and 2. Every cow (experiments 1, 2, and 3) was blood sampled at selected intervals for progesterone and oestradiol assays and inseminated at oestrus. In experiment 1, a higher percentage of GnRH-treated cows ovulated after the first PGF(2alpha) injection (90% versus 50%; P<0.05). The GnRH-treated cows tended to have a larger dominant follicle present at the time of the second PGF(2alpha) injection (16.5+/-0.5 mm versus 15.0+/-0.7 mm; P<0.10). The percentage of cows that ovulated after the second PGF(2alpha) injection was similar (60%). In experiment 2, cows treated with ECP had higher peak preovulatory concentrations of oestradiol in plasma (6.99+/-0.63 versus 3.63+/-0.63; P<0.01) following the second PGF(2alpha) injection and a higher percentage ovulated (86% versus 43%; P<0.05). A higher percentage of PGPE(1)-treated cows in experiment 3 were observed in standing oestrus and ovulated after the second PGF(2alpha) injection (standing oestrus, 26.4, 34.3, and 62.6%, P<0.01; ovulated, 56, 63, and 78%, P<0.05; PP, PGP, and PGPE(1), respectively). In conclusion, the PGP protocol increased the number of cows that ovulated after the first PGF(2alpha) injection and produced a more mature dominant follicle at the time of the second PGF(2alpha) injection. Adding ECP to PGP (PGPE(1)) enhanced the expression of oestrus and increased ovulation percentage. The combination of PGP and ECP is potentially a new method to routinely synchronise oestrus and ovulation in dairy cows.     

Circulating and urinary metabolites of PGE2 and PGF2a

Fig. 1 summarizes the structures of primary PGE₂ and PGF_2a (upper line), their initially formed 15-ketodihydro-metabolites which appera early in blood after release (middle), and their β- and ω-oxidized metabolites, which appear later and remain longer in the circulation and also dominate the urinary profile (lower line). No single compound can be put forward as the ideal assay parameter: depending on aim and design of the study, either of these compounds may be monitored. The chemical instability of PGE compounds should however be kept in mind: generally it is safer to induce degradation by alkali treatment into a stable product prior to assay.     

Expression and detection of oestrus in cattle

For herds using AI heat detection rate and calving rate are the two major determinants of compactness of calving, of the proportion of cows that fail to conceive in a defined breeding season. Numerous factors affect the expression of heat including, housing arrangement, floor surface, feet and leg problems and status of herd mates. The number of mounts a cow receives increases with the number of cows that are in heat simultaneously up to about 3-4 cows in heat. Generally, cows that are themselves in heat, coming into heat or were recently in heat are most likely to mount a cow that is in heat. Cows that are at the mid-stages of their cycles (day 5 to about day 16) are least likely to mount a cow that is in heat and consequently could be termed "poor heat detectors". Similarly, cows that are pregnant show less interest in mounting other cows that are in heat. In smaller herds and as more cows become pregnant the likelihood of more than one cow being heat on any given day becomes less, consequently, making heat detection more difficult. The single most important factor affecting heat detection efficiency is that those responsible for checking for heat should fully understand the signs of heat and be fully committed to heat detection for as long as it is planned to use Al. Technological aids to improve heat detection include the use of tail paint, oestrous synchronisation, vasectomised bulls, pressure activated heat mount detectors, radio telemetric devices, pressure sensitive mount count devices and pedometers. As herd size increases and labour become more expensive there will be a greater adoption of some of these technological aids.     

Comparison of control of oestrus and ovulation in sheep by an ear implant (SC-21009) or by intravaginal sponge (cronolone or map)

Oestrus and ovulation were observed in 234 Galway ewes in the breeding season in a preliminary evaluation of an implant progestagen treatment. A miniature ear implant (3 mg SC-21009) was used in a comparison with two intravaginal sponges (30 mg Cronolone and 60 mg medroxy progesterone acetate (MAP)). Each progestagen treatment was used in conjunction with pregnant mare serum gonadotrophin (PMSG) (0, 375 i.u. and 750 i.u.). The percentage of ewes showing oestrus after treatment was significantly affected by progestagen (Cronolone, 95%; MAP, 71%; SC-21009, 74%; P < 0.01), but not by PMSG dose level (0.1 < P < 0.2). Oestrus onset was similar among treatments, but heats ended significantly earlier in implant sheep. Significantly (P < 0.01) more ewes ovulated following Cronolone treatment (92%) than following MAP (74%) or SC-21009 (71%), and there was also a significant effect of PMSG (0, 73%; 375 i.u., 86%; 750 i.u., 93%; P < 0.01). PMSG dose level had a highly significant effect on the mean ovulation rate (0, 1.23; 375 i.u., 1.52; 750 i.u., 2.12; P < 0.001).     

Laminaria augmentation of intra-amniotic PGF2 for midtrimester pregnancy termination

In our hands, intra-amniotic PGF_2^α 40 mg for midtrimester pregnancy termination had a mean infusion to abortion interval of 29.4 hr. However, pretreatment of 230 patients with laminaria tents inserted 14–18 hr before PGF_2^α infusion resulted in a dramatically reduced time to abortion (14.3 hr mean) with a low incidence of gastrointestinal and other side effects. Laminaria tents inserted at the same time as PGF_2^α infusion in 26 patients also resulted in reduced time to abortion (18.6 hr mean). In the laminaria pretreated group, the infusion to abortion interval was indirectly related to the number of laminaria inserted and not to the nulliparous or parous state. Although we have made significant strides in shortening the abortion interval in the hospital, retained placentae and blood loss persist as problems related to the use of prostaglandin for abortion.     

Intracellular recording of cerebral cortical actions of prostaglandin F2α (PGF2α)

Our reported data on the cortical inhibitory actions of prostaglandin F_2α (PGF_2α) and the diversity of data in the literature on cerebral PG actions are examined here in the light of intracellular recording which provides the requisite membrane data for the first time. Thus, 1) intracellular recording from the cat cerebral cortex is obtained for the actions of PGF_2α and for norepinephrine (NE) and serotonin (5HT). 2) The parallel changes in firing and polarization and the simultaneous transmembrane conductance changes are qualitatively identical for PGF_2α, NE and 5HT. 3) The reduction in firing accompanied by hyperpolarization indicates that PGF_2α, NE and 5HT all inhibit these cells. 4) The ionic species responsible for this inhibition is such that it increased the transmembrane resistance, and this was true for all three. 5) The changes in membrane parameters, identical in direction for PGF_2α and NE, but stronger for the latter, constitute conditions that can lead to competitive inhibition and therefore conote, presumably, actions at the same or related receptors. Such competition with evoked cortical field potentials is shown in the preceding paper.     

PGE2 and PGF2α release by human peritoneal macrophages in endometriosis

Objective: To test for differences in the amount and activity of peritoneal macrophages present in the peritoneal fluid of women with, and without endometriosis using prostaglandin release by macrophages in culture as a marker.Patients: Women of reproductive age undergoing laparoscopy for infertility or chronic pelvic pain with postoperative diagnosis of endometriosis and women undergoing laparoscopy for sterilization.Methods: Peritoneal fluid was aspirated during laparoscopy, volume was recorded, macrophages were isolated via a Ficoll Paque gradient and kept in primary culture. PGE₂ and PGF_2α release of the cells were measured before and after stimulation with zymosan.Results: Women with endometriosis had significantly more peritoneal macrophages than controls. Peritoneal macrophages of women with endometriosis released significantly more PGE₂ than those of the control group: 8.4 ± 2.0 versus 1.4 ± 0.4 ng/ml/10⁶cells (mean ± SEM, p=0.0005) and PGF_2α : 10 ± 4.3 (endometriosis) versus 1.8 ± 0.4 (control) ng/ml/10⁶cells (mean ± SEM, p = 0.045).Conclusion: There is a significant increase in the amount of prostaglandins released by peritoneal macrophages from women with endometriosis. These prostaglandins might alter uterine and tubal contractility, thereby affecting fertility.     

Plasma 13, 14-dihydro-15-keto-PGF2 (PGFM) in pregnant and nonpregnant heifers prior to and during surgery and following intrauterine injection of PGF2

On day 17 postestrus or postmating, heifers were given intrauterine injections of saline (2 pregnant, 2 non-pregnant) or 200 μg PGF₂α (7 pregnant, 6 nonpregnant) through cannulae installed surgically into the uterine horn ipsilateral to the corpus luteum bearing ovary. Jugular blood samples were collected prior to the laparotomy at which the cannulae were installed during surgery, and for 90 min following the intrauterine injection. Plasma was assayed for progesterone and 13,14-dihyro-15-keto-PGF₂α )PGFM). Laparotomies were reopened to confirm proper cannula placement and to determine if blastocysts were present in mated heifers. Concentrations of PGFM were higher in pregnant compared to nonpregnant heifers during the presurgery (68 26 24 26 pg/ml; P < 0.25) and surgery (186 47 65 17 pg/ml; P < .05) periods. Pregnancy status did not alter the mean concentrations of PGFM (pregnant, 554 70 pg/ml; nonpregnant, 422 81 pg/ml) or the half-life of its decline in concentration (18 min) following intrauterine injection of PGF₂α. Pregnancy at 17 days in cattle does not appear to influence PGF₂α transport from the uterine lumen or its metabolism in the uterus or elsewhere in response to an acute intrauterine injection.     

Synthesis, structure and properties of TTF-carboxylate bridged paddlewheel dirhodium complexes, Rh2(BuCO2)3(TTFCO2) and Rh2(BuCO2)2(TTFCO2)2

Reaction of tetrathiafulvalene carboxylic acid (TTFCO₂H) with paddlewheel dirhodium complex Rh₂(Bu^tCO₂)₄ yielded TTFCO₂-bridged complexes Rh₂(Bu^tCO₂)₃(TTFCO₂) (1) and cis- and trans-Rh₂(Bu^tCO₂)₂(TTFCO₂)₂ (cis- and trans-2). Their triethylamine adducts [1(NEt₃)₂] and cis-[2(NEt₃)₂] were purified and isolated with chromatographic separation, and characterized with single crystal X-ray analysis. Trans-[2(NEt₃)₂] is not completely separated from a mixture of cis- and trans-[2(NEt₃)₂], but its single crystals were obtained from a solution of the mixture. A three-step quasi-reversible oxidation process was observed for 1 in MeCN. The first two steps correspond to the oxidation of the TTFCO₂ moiety and the last one is the oxidation of the Rh₂ core. The oxidation of cis-2 is observed as a two-step process with very similar E_1/2 values to those of the first two processes for 1. Both 1⁺ and cis-2²⁺ in MeCN at room temperature show isotropic ESR spectra with a g value of 2.008 and a_H = 0.135 mT for two equivalent H atoms and a_H = 0.068 mT for one H atom. The redox and ESR data of cis-2 suggest that the intramolecular interaction between the TTF moieties is very small.     

Effect of PGF2α and 15(S)-15-methyl PGE2 methyl ester on feline generalized penicillin epilepsy

The effect of PGF_2α and 15(S)-15-methyl PGE₂ methyl ester on transient generalized epilepsy in the cat induced by penicillin was examined. Epileptic activity before and after administration of the prostaglandins by several routes was determined from continuous EEG recordings and expressed in epileptic bursts per min. The PGE₂ analogue given in single non-toxic doses (1.6–3 μg/kg) by intramuscular or intravenous routes at the peak of epileptic activity significantly reduced epileptic activity for up to four hours. Subcutaneous administration was less effective. PGF_2α given by the intramuscular route (0.3 mg/kg) also markedly reduced the number of epileptic bursts. Increasing the dosage 4-fold almost completely suppressed epileptic activity. Intracarotid infusion of PGF_2α for one hour (10 μg/min) almost abolished all epileptic activity. Neither prostaglandin given in non-toxic doses induced EEG abnormalities in non-epileptic cats. Toxic doses of the E₂ analogue (>16 μg/kg) caused bilaterally synchronous high voltage slow wave activity. It is concluded that these prostaglandins reduce penicillin epilepsy in the cat. The findings are consistent with either a direct excitatory action on neurones of the medial reticular formation or antagonism of the depressant action of norepinephrine on Purkinje cells.     

Synthesis and characterization of SrCu2(O2CR)3(bdmap)3 and Bi2(O2CCH3)4(bdmap)2(H2O) (R = CH3, CF3; bdmap = 1,3-bis(dimethylamino)-2-propanolato)

New mixed metal complexes SrCu₂(O₂CR)₃(bdmap)₃ (R = CF₃ (1a), CH₃ (1b)) and a new dinuclear bismuth complex Bi₂(O₂CCH₃)₄(bdmap)₂(H₂O) (2) have been synthesized. Their crystal structures have been determined by single-crystal X-ray diffraction analyses. Thermal decomposition behaviors of these complexes have been examined by TGA and X-ray powder diffraction analyses. While compound 1a decomposes to SrF₂ and CuO at about 380°C, compound 1b decomposes to the corresponding oxides above 800°C. Compound 2 decomposes cleanly to Bi₂O₃ at 330°C. The magnetism of 1a was examined by the measurement of susceptibility from 5–300 K. Theoretical fitting for the susceptibility data revealed that 1a is an antiferromagnetically coupled system with g = 2.012(7), −2J = 34.0(8) cm⁻¹. Crystal data for 1a: C₂₇H₅₁N₆O₉F₉Cu₂Sr/THF, monoclinic space group P2₁/m, A = 10.708(6), B = 15.20(1), C = 15.404(7) Å, β = 107.94(4)°, V = 2386(2) ų, Z = 2; for 1b: C₂₇H₆₀N₆O₉Cu₂Sr/THF, orthorhombic space group Pbcn, A = 19.164(9), B = 26.829(8), C = 17.240(9) Å, V = 8864(5) ų, Z = 8; for 2: C₂₂H₄₈O₁₁N₄Bi₂, monoclinic space group P2₁/c, A = 17.614(9), B = 10.741(3), C = 18.910(7) Å, β = 109.99(3)°, V = 3362(2) ų, Z = 4.     

Prostaglandin E2 opunteracts the effects of PGF2α in indomethacin treated cycling gilts

Twenty crossbred gilts with at least 2 consecutive estrous cycles of 18 to 21 days in length were used to study the effects of prostaglandins E₂ and F₂α (PGE₂ and PGF₂α) on luteal function in indomethacin (INDO) treated cycling gilts. Intrauterine and jugular vein catheters were surgically palced before day 7 of the treatment estrous cycle and gilts were randomly assigned to 1 of 5 treatment groups (4/groups). With exception of the controls (Group I) all gilts received 3.3 mg/kg INDO every 8 h, Groups III, IV and V received 2.5 mg PGF₂; 2.5 mg PGF₂α + 400 μg PGE₂ every 4 hr, or 400μg PGE₂ every 4 h, respectively. All treatments were initiated on day 7 and continued until estrus or day 23. Jugular blood for progesterone analysis was collected twice daily from day 7 to 30. Estradiol-17β (E₂-17β) concentrations were dtermined in samples collected twice daily, from 2 d before until 2 d following the day of estrus onset. When compared to pretreatment values, estrous cycle length was unaffected (P>0.05) in Group I, prolonged (P<0.05) in Groups II, IV and V; and shortened (P<0.05) in Group III. The decline in plasma progesterone concentration that normally occurs around day 15 was unaffected (P>.05) in Group I; delayed (P<0.05) in Groups II, IV and V; and occurred early (P<0.05) in Group III. Mean E₂-17β remained high (31.2 ± 4.9 to 49.3 ± 3.1 pg/ml) in Groups III and IV, while the mean concentrations in Groups III and V varied considerably (17.0 ± 2.0 to 52.2 ± 3.5 pg/ml). The results of this study have shown that PGE₂ will counteract the effects of PGF₂α in INDO treated cycling gilts. The inclusion of PGF₂α appeared to either stimulate E₂-17β secretion or maintain it at a higher level than other treatments.     

Effect of PGF2α and 15(S)-15-methyl PGE2 methyl ester on feline generalized penicillin epilepsy

The effect of PGF_2α and 15(S)-15-methyl PGE₂ methyl ester on transient generalized epilepsy in the cat induced by penicillin was examined. Epileptic activity before and after administration of the prostaglandins by several routes was determined from continuous EEG recordings and expressed in epileptic bursts per min. The PGE₂ analogue given in single non-toxic doses (1.6–3 μg/kg) by intramuscular or intravenous routes at the peak of epileptic activity significantly reduced epileptic activity for up to four hours. Subcutaneous administration was less effective. PGF_2α given by the intramuscular route (0.3 mg/kg) also markedly reduced the number of epileptic bursts. Increasing the dosage 4-fold almost completely suppressed epileptic activity. Intracarotid infusion of PGF_2α for one hour (10 μg/min) almost abolished all epileptic activity. Neither prostaglandin given in non-toxic doses induced EEG abnormalities in non-epileptic cats. Toxic doses of the E₂ analogue (>16 μg/kg) caused bilaterally synchronous high voltage slow wave activity. It is concluded that these prostaglandins reduce penicillin epilepsy in the cat. The findings are consistent with either a direct excitatory action on neurones of the medial reticular formation or antagonism of the depressant action of norepinephrine on Purkinje cells.