97 PRELIMINARY DESCRIPTIVE STUDY OF EQUINE PLACENTA GENERATED AFTER TRANSFER OF IN VIVO- AND IN VITRO-PRODUCED EMBRYOS

2017 ◽  
Vol 29 (1) ◽  
pp. 156 ◽  
Author(s):  
A. Lanci ◽  
J. Mariella ◽  
B. Merlo ◽  
C. Castagnetti ◽  
E. Iacono
Keyword(s):  
Embryo Transfer ◽  
Intracytoplasmic Sperm Injection ◽  
Reproductive Technologies ◽  
Control Group ◽  
Placental Development ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Placental changes associated with artificial reproductive technologies have been described in several species, but little information is available in horses. Joy et al. (2012) reported that human placentas from intracytoplasmic sperm injection derived embryos were heavier and thicker than those produced after natural conception. Despite the most growing interest and efficiency of artificial reproductive technologies in equine species, only recently, Pozor et al. (2016) described placental abnormalities in pregnancies generated by somatic cell NT, but there are no studies on equine placenta generated by intracytoplasmic sperm injection and traditional embryo transfer. In the present preliminary study, macroscopic differences of placentas generated after transfer of in vitro- or in vivo-produced embryos were registered. Twelve Standardbred recipient mares with pregnancy generated after transfer of in vivo-derived (Group 1) and in vitro-derived (Group 2) embryos were enrolled; 10 Standardbred mares with pregnancy derived by traditional AI were included as control (Group 3). All pregnancies were physiological, and newborn foals were healthy. Mare age, parity, length of pregnancy, gross evaluation and weight of placenta, total length of umbilical cord (UC), length of UC, number of UC coils, foal sex, and weight at birth were registered. Collected data are listed in Table 1 and are expressed as mean ± standard deviation. Differences between groups were evaluated by 1-way ANOVA, and the difference in proportion of overweight placentas was evaluated with the Fisher test. The gross evaluation of placenta revealed 8/12 placentas (2/4 Group 1; 6/8 Group 2) were heavier than 11% (Madigan, 1997) due to oedema of the chorioallantois. No overweight placentas were registered in Group 3. In Group 1, 1/4 placentas had villous hypoplasia, and in Group 2, 1/8 placentas had cystic pouches on the UC. There were no significant differences among groups. However, the proportion of overweight placentas between Group 2 (6/8) and Group 3 (0/10) approached significance (P = 0.06). Although preliminary, the results of the present study suggest that production of equine embryos in vitro may lead to alterations in placental development. Several studies in cattle and sheep have suggested that alterations in the placentas of pregnancies derived from in vitro-produced embryos are related to effects of culture on epigenetic regulation. Less is known in the horse about the effects of in vitro embryo production on placental development; thus, further research in this area is necessary. Table 1. Characteristics of full-term placentas derived from AI or embryo transfer with in vivo- and in vitro-produced embryos

scholarly journals Effect of Different Finishing and Polishing Methods for Color Stability of the E-Max Dental Ceramics: In vitro Study

2021 ◽  
Vol 14 (4) ◽  
pp. 1508-1513
Author(s):  
Ibraheem F Alshiddi
Keyword(s):  
Surface Brightness ◽  
Color Stability ◽  
Color Measurement ◽  
Control Group ◽  
Group 4 ◽  
Significant Difference ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

In order to assess the influence of finishing and polishing on the surface brightness and color stability of the ceramic veneer, fifty specimens were fabricated with 10 mm diameter and 2 mm thickness using IPS E-Max Ceramic. After glazing, 10 specimens were untouched as control group, and the other 40 specimens were abraded using 125µm diamond bur to create surface roughness. Forty specimens were divided into four groups (n=10), in group 1: specimens were finished using diamond point, in group 2 specimens’ surface was polished with a polishing kit, Group 3: Each specimen surface was polished with the polishing kit as in protocol 2 and was polished a polishing past and group 4 Each specimen was glazed by heating at 621℃ for 3 minutes followed by a temperature increase of 83℃/min up to 918℃ for 30 seconds. Color measurement was performed using spectrophotometer. Color stability data were analyzed using two-way ANOVA and Tukey’s HSD test (α=0.05). For Ra values, paired-samples t-tests were used to analyze the data and compare groups. The change in L and E showed a significant difference among the study groups; (group 1, group 2, group 3 and group 4) with respect to three variables L, a and b. A significant difference was noted when compared each group with the control; however, only group 2 showed a significant difference from group 4; the remaining groups demonstrated similar findings for all three variables. The study displayed a significant impact of the finishing and polishing technique on the surface brightness and color stability of ceramic restoration. However, it was evident that combination of two or three polishing techniques which includes polish kit and glaze enhances the surface finish and adds color stability by alternating the yellow – blue axis (increase in b) and red- green axis (decrease in a).

scholarly journals study the effect of alcoholic and watery extracts of garlic and onion plants on growth of candida albicans and Cryptococcus neoformans in vitro&vivo

2008 ◽  
Vol 32 (2) ◽  
pp. 29-38
Author(s):  
Abd-Alshaheed D. A.
Keyword(s):  
Candida Albicans ◽  
Cryptococcus Neoformans ◽  
Included Study ◽  
Control Group ◽  
Alcoholic Extract ◽  
Ofcandida Albicans ◽  
Group 3 ◽  
Group 2

This research included study the effect of garlic and onion plantsextracts(alcoholic and watery) in vitro in three different concentrations15%,25%,35% and in vivo in experimental white mice .Research wasperformed by three experiments, first one was conducted to studyeffectiveness of different concentration of alcoholic and watery garlicextract on growth of candida albicans and Cryptococcus neoformans invitro, showed that the effect of alcoholic extract on the growth of candidaalbicans was inhibitory,started from 0.4 mm to 0.1 mm compared withcontrol plats 4.2 mm ,where as the results of the effect on the growth ofCryptococcus neoformans showed more clearness and the inhibitionstarted from 0.6 to inhibit all the growth in plat in comparison withcontrol plats1.4 mm. While the effect of watery garlic extract showed lesseffect and the inhibition began from 0.5 mm to 0.2 mm for candidaalbicans , but the growth inhibition of Cryptococcus neoformans beganfrom 0.4 to 0.15 mm.The second experiment was the same as the firstexperiment , but using alcoholic and extracts onion , the growth ofcandida albicans inhibited by alcoholic exract from 0.6 mm to no growthin the plat , but the inhibition of Cryptococcus neoformans was startedfrom 0.5mm to 0.2 mm for alcoholic onion extract. While the wateryonion extract effect on the growth of candida albicans the inhibitionstarted from 1.6 mm to 1 mm ,but the inhibition of Cryptococcusneoformans was began from 1 mm to 0.3 mm.Third experiment was study the effect of crude garlic and onion alcoholicextract ointment 1% on experimental infection in mice , using 30experimental mice divided to 6 equal groups,each group include 5 mice*groups which infected with candida albicans treated :The group 1,2,3,expermrutly infected with candida albicans ,where asgroup 3,4,6 were infected with Cryptococcus neoformans for 1,2,3 group,treted with the ointment of alcoholic extract of garlic, group 2 treatedwith alcoholic extract ointment of onion, where as group 3 left with notreatment as a control group

scholarly journals Testing the Medina embolization device in experimental aneurysms

2019 ◽  
Vol 131 (5) ◽  
pp. 1485-1493 ◽  
Author(s):  
Robert Fahed ◽  
Tim E. Darsaut ◽  
Igor Salazkin ◽  
Guylaine Gevry ◽  
Jean Raymond
Keyword(s):  
Flow Diverter ◽  
Group 3 ◽  
Group 2 ◽  
Aneurysmal Neck ◽  
Near Occlusion ◽  
Platinum Coils ◽  
Group 1

OBJECTIVEThe Medina embolization device (MED) is a novel, braided self-expanding endovascular device designed to occlude aneurysms by constructing an in situ intrasaccular flow diverter. Although a single device can be positioned at the neck of simple spherical in vitro aneurysms, the best way to occlude more complex in vivo aneurysms (using multiple MEDs or a combination of MEDs and platinum coils) is currently unknown.METHODSFifty-two aneurysms of 3 different types were created in 31 canines, yielding 48 patent aneurysms. Treatments were randomly allocated by drawing lots: group 1, MEDs alone (n = 16); group 2, MEDs plus standard platinum coils (n = 16); and group 3, control aneurysms treated with coils alone (n = 16). Angiographic results were scored and compared immediately following treatment completion and at 3 months. Specimens were photographed and the extent of neointimal closure of the aneurysmal neck scored, followed by histopathological analyses.RESULTSAngiographic scores of 0 or 1 (occlusion or near occlusion) were initially obtained in 2 of 16 (12.5%, 95% CI 1.6%–38.3%) group 1 (MEDs alone), 3 of 16 (18.7%, 95% CI 4%–45.6%) group 2 (MEDs plus coils), and 10 of 16 (62.5%, 95% CI 35.4%–84.8%) group 3 (coils alone) aneurysms (p = 0.005). At 3 months, scores of 0 or 1 were found in 11 of 16 (68.7%, 95% CI 41.3%–89.0%) group 1, 9 of 16 (56.2%, 95% CI 29.9%–80.2%) group 2, and 8 of 16 (50%, 95% CI 24.7%–75.3%) group 3 aneurysms (p = 0.82). Neointimal scores were similar for the 3 treated groups (p = 0.66).CONCLUSIONEndovascular treatment of experimental aneurysms with MEDs or MEDs and coils showed angiographic occlusion and neointimal scores at 3 months that were similar to those achieved with standard platinum coiling.

Effect of intracisternal antithrombin III on subarachnoid hemorrhage-induced arterial narrowing

1989 ◽  
Vol 70 (4) ◽  
pp. 599-604 ◽  
Author(s):  
Dennis G. Vollmer ◽  
Kazuhiro Hongo ◽  
Neal F. Kassell ◽  
Hisayuki Ogawa ◽  
Tetsuya Tsukahara ◽  
...  
Keyword(s):  
Basilar Artery ◽  
Antithrombin Iii ◽  
White Male ◽  
Rabbit Model ◽  
Content Type ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

✓ The ability of antithrombin III, an endogenous plasma glycoprotein, to reverse the arterial narrowing in a rabbit model of cerebral vasospasm was evaluated. The vasodilator activity of antithrombin III on rabbit arteries was first assessed in vitro using a myograph-arterial ring preparation. Antithrombin III (10 IU/ml) induced a 55.4% ± 2.66% (mean ± standard error of the mean) relaxation in basilar artery precontracted with serotonin (5-HT) in five specimens as compared with a 9.8% ± 1.6% relaxation of common carotid artery in six specimens. For in vivo analysis, 21 New Zealand White male rabbits were separated into three groups: Group 1 served as normal controls; Group 2 received a subarachnoid blood injection (SAH) and were sacrificed on Day 3 thereafter; and Group 3 animals were subjected to SAH, then received a 2-hour intracisternal infusion of antithrombin III (100 IU) in saline prior to sacrifice on Day 3. Basilar artery caliber was determined using a morphometric method to analyze perfusion-fixed arterial segments. Control basilar artery diameter in Group 1 was 0.64 ± 0.02 mm. In Group 2 a 27% reduction in arterial caliber to 0.47 ± 0.03 mm was observed by Day 3 post SAH (p < 0.0001). Group 3 animals had a mean basilar artery diameter of 0.68 ± 0.02 mm. This was significantly larger than the untreated SAH rabbits in Group 2 (p < 0.0001), but not different from control artery diameters in Group 1. The findings demonstrate that antithrombin III in saline has a significant ability to reverse delayed narrowing of the rabbit basilar artery after SAH.

scholarly journals Effect of the number of thermocycles on microleakage of resin composite restorations

2003 ◽  
Vol 17 (4) ◽  
pp. 337-341 ◽  
Author(s):  
Flávia Bittencourt Pazinatto ◽  
Bruno Barbosa Campos ◽  
Leonardo César Costa ◽  
Maria Teresa Atta
Keyword(s):  
Resin Composite ◽  
Control Group ◽  
Group 4 ◽  
Thermal Changes ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
Number Of Cycles ◽  
Group 1

Thermocycling simulates, in vitro, thermal changes that occur in the oral cavity. The aim of this study was to evaluate the influence of the number of cycles on microleakage. Class V cavities (1.5 mm deep, 3 mm in height and 3 mm in width) were prepared in bovine teeth, restored with a Single Bond/Z250 restorative system (3M/ESPE) and then divided into five groups of ten teeth each: group 1 was not thermocycled (control group), and groups 2, 3, 4 and 5 were thermocycled 500, 1,000, 2,500 and 5,000 times, respectively (5º-55º ± 2ºC, 15 s dwell time). The teeth were immersed in 0.5% basic fuchsin aqueous solution for 24 h, sectioned and the sections with the highest degree of microleakage were selected, scanned and the extent of dye penetration was measured by the ImageTool program. The results submitted to one-way ANOVA showed no significant differences between the groups (p > 0.05). The averages of microleakage values in millimeters were: group 1 (3.92); group 2 (3.13); group 3 (4.48); group 4 (4.33) and group 5 (3.42). Thus, it was concluded that there is no relation between the increase of the number of cycles and the increase in microleakage.

25 DEVELOPMENTAL COMPETENCE OF CLONED BUFFALO (BUBALUS BUBALIS) EMBRYOS PRODUCED BY TRANSFECTED OR NONTRANSFECTED FIBROBLASTS TRANSFER TO ENUCLEATED OOCYTES DERIVED FROM OVUM PICK-UP AND ABATTOIR OVARIES

2015 ◽  
Vol 27 (1) ◽  
pp. 105
Author(s):  
C. Yang ◽  
J. Shang ◽  
H. Zheng ◽  
M. Chen ◽  
F. Huang ◽  
...  
Keyword(s):  
Natural Science ◽  
Fluorescent Protein ◽  
Developmental Competence ◽  
Cleavage Rate ◽  
Reconstructed Embryos ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

The objective of this study was to explore whether fibroblasts transfection and the source of oocytes – ovum pick-up (OPU) versus abattoir ovaries – affected the in vitro and in vivo developmental competence of somatic cell nuclear transferred (SCNT) embryos in buffalo. To this aim, the serum-starved ear fibroblasts were fused into enucleated oocytes derived from abattoir ovaries (Group 1) and OPU (Group 2). Furthermore, the enucleated buffalo oocytes derived from abattoir ovaries were also fused with pEGFP-N1 transfected ear fibroblasts, and the cloned embryos were enhanced green fluorescent protein (EGFP)-positive confirmed by fluorescence microscopy (Group 3). The reconstructed embryos cultured in Groups 1 to 3 were 262, 83, 120, respectively (5 replicates); and the data were analysed by one-way ANOVA (SPSS Inc., Chicago, IL, USA). As a result, the cleavage rate in Group 3 was significantly higher than that in Group 1 (75.0% v. 54.3%; P < 0.01), and the total blastocyst rate of reconstructed embryos in Group 3 (27.3%) was significantly higher than that in Group 1 (17.4%; P < 0.01) and Group 2 (24.4%; P < 0.05). The SCNT blastocysts were vitrified with 20% ethylene glycol + 20% dimethylsulfoxide + 0.5 M sucrose; the cryosurvival rates of SCNT blastocysts in the 3 groups were not different from each other (90.0%, 94.7%, 92.3%). Following culture, the cryosurvived blastocysts were transferred into synchronized local and crossbred buffaloes, with each recipient receiving 1 or 2 embryos. The pregnancy rates after transferring embryos derived from Groups 1 to 3 were not different from each other, and were 18.75% (3/16), 33.33% (4/12), and 26.67% (4/15), respectively. These results indicate that the oocytes derived from OPU can be enucleated as recipient cytoplasm and transfected fibroblast can be adopted as nuclei donor without decreasing the SCNT efficiency in buffalo.This research was supported by grants from the National Natural Science Foundation of China (31160456) and the Natural Science Foundations of China under Grant No. 0991011, No. 2011GXSFB018045).

Anthelmintic effects of Prosopis laevigatan-hexanic extract against Haemonchus contortus in artificially infected gerbils (Meriones unguiculatus)

2009 ◽  
Vol 84 (1) ◽  
pp. 71-75 ◽  
Author(s):  
A.F. De Jesús-Gabino ◽  
P. Mendoza-de Gives ◽  
D.O. Salinas-Sánchez ◽  
M.E. López-Arellano ◽  
E. Liébano-Hernández ◽  
...  
Keyword(s):  
Plant Extract ◽  
Haemonchus Contortus ◽  
Meriones Unguiculatus ◽  
Tween 20 ◽  
Control Group ◽  
Group 3 ◽  
Group 2 ◽  
Group 1 ◽  
Anthelmintic Effect

AbstractThe anthelmintic effect of Prosopis laevigata (mezquite) n-hexanic extract was evaluated against Haemonchus contortus endoparasitic stages in artificially infected gerbils (Meriones unguiculatus). Prosopis laevigata leaves were collected from the Sierra de Huautla, Ecological Reserve of the Biosphere, in Morelos State, Mexico; dehydrated under shade and macerated with n-hexane for 3 days, followed by distillation for 8 h. This procedure was repeated three times and the final extract was kept at 4°C. The in vivo effect of the plant extract was evaluated in gerbils artificially infected with H. contortus. Plant extract concentration was 40 mg/ml. Three groups of gerbils were as follows: group 1 (n = 7), P. laevigata extract at 100 μl intraperitoneally (IP); group 2 (n = 6), control – Tween 20 in water at a single dose of 100 μ l IP; group 3 (n = 8) also served as a control, receiving water only, to determine the mortality due to causes other than the plant extract. An additional group of seven gerbils (group 4) was administered fenbendazole, as a positive control. Five days later the animals were euthanized and stomach and mucosa removed to quantify the nematodes. Data were analysed using the Student's t-test to compare the mean of nematodes obtained in groups 1, 2 and 3. The parasite population in the plant extract treated group 1 was reduced by 42.5% (P < 0.05) with respect to the control group 2; and when control group 3 was used for comparison the parasitic reduction was estimated as 53.11%. This study shows the in vivo anthelmintic effect of P. laevigatan-hexane extract for the first time, using gerbils as an in vivo model, with potential use in sheep.

scholarly journals Detection and in vitro and in vivo characterization of porcine circovirus DNA from a porcine-derived commercial pepsin product

2004 ◽  
Vol 85 (11) ◽  
pp. 3377-3382 ◽  
Author(s):  
M. Fenaux ◽  
T. Opriessnig ◽  
P. G. Halbur ◽  
Y. Xu ◽  
B. Potts ◽  
...  
Keyword(s):  
Porcine Circovirus Type ◽  
Human Infection ◽  
Porcine Circovirus ◽  
Specific Pathogen ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Non-pathogenic porcine circovirus type 1 (PCV1) and pathogenic PCV2 are widespread in swine herds. In this study, the detection and characterization of PCV1 and PCV2 DNA from porcine-derived commercial pepsin are reported. The complete genomic sequences of the pepsin-derived PCV1 and PCV2 share 76 % nucleotide sequence identity with each other and 95–99 % identity with respective North American PCV1 and PCV2 isolates. However, the PCV-contaminated pepsin lacks infectivity in PK-15 cells. To further assess the infectivity of the contaminating pepsin in vivo, 16 5-week-old, specific-pathogen-free pigs were divided randomly into three groups: pigs in group 1 (n=5) were each inoculated intramuscularly and intranasally with 4 ml PBS buffer as negative controls, those in group 2 (n=6) were each inoculated with 400 mg contaminated pepsin dissolved in 4 ml PBS and those in group 3 (n=5) were each inoculated with 4×104·3 TCID50 PCV2 as positive controls. PCV2 viraemia, seroconversion and pathological lesions were detected in group 3 pigs, but not in group 1 or 2 pigs, confirming that the contaminating PCVs were non-infectious. Nevertheless, the detection of PCV DNA in a porcine-derived commercial product raises concern for potential human infection through xenotransplantation.

Effect of simultaneous blockade of androgen and estrogen receptors on prostate cancer: In vivo study.

2013 ◽  
Vol 31 (6_suppl) ◽  
pp. 214-214
Author(s):  
Rafael Nunez-Nateras ◽  
Erin N. Ferrigni ◽  
Naomi M. Gades ◽  
Erik P. Castle
Keyword(s):  
Growth Inhibition ◽  
Control Group ◽  
Group 4 ◽  
Combined Administration ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
Castrate Resistant ◽  
Group 1

214 Background: In our preliminary in vitro studies, we have demonstrated evidence of enhanced apoptosis and inhibition of cellular proliferation in both hormone sensitive and castrate resistant prostate cancer (PCa) cell lines using a combination of an antiandrogen (Bicalutamide) and a selective estrogen receptor modulator (Raloxifene). The aim of this study was to study the effect of the administration of these two drugs in in vivo models of castrate resistant PCa. Methods: In vivo model consisted on NCr Nude: Mice bearing s.c. human prostate (PC3 cell line) xenografts. Based on the treatment received, mice were divided into 5 groups as follows: Group 1: No drugs (control); Group 2: Bicalutamide 50mg; Group 3: Raloxifene 60 mg; Group 4: Combined administration of Bicalutamide 50 mg and Raloxifene 60 mg; Group 5 Combined administration of Bicalutamide 150 mg and Raloxifene 120 mg. A total of 10 mice where included in each group. All drugs dosages were converted to their equivalent in the mice. Drugs were administered by gavage technique to the mice once per day for a total of 14 days. Results: As expected, Bicalutamide administered alone causes minimal inhibition without reaching statistical significance (Group 2: 0.34 g Vs Group 1: 0.40 g; p=0.073). Although Raloxifene causes some marked growth inhibition, its effect is not statistically significant (Group 3: 0.31 Vs Group 1: 0.40 g; p=0.062). Bicalutamide and Raloxifene, when administered in combination, induced prominent growth inhibition in PC3 tumors when compared to the control group (Group 4: 0.26 g Vs Group 1: 0.40 g; p=0.038). Growth inhibition is significantly more evident when the drugs dosages are increased (Group 5: 0.17 g Vs Group 1: 0.40 g; p=0.024). Conclusions: The simultaneous administration of Bicalutamide and Raloxifene appears to have a synergistic effect on tumor growth inhibition in PC3 xenografts. The pathway(s) responsible for this observation may be independent of the androgen receptor as PC3 cells are AR negative and still affected by the combination over the drugs administered alone. Research is warranted to identify these potential pathways.

scholarly journals Reduced LH sensitivity in vivo and in vitro of corpora lutea induced during anoestrus by GnRH, and during the late breeding season, in Scottish Blackface ewes

2004 ◽  
Vol 183 (3) ◽  
pp. 517-526 ◽  
Author(s):  
T A Bramley ◽  
D Stirling ◽  
G S Menzies ◽  
D T Baird
Keyword(s):  
Breeding Season ◽  
High Plasma ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Group 4 ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Scottish Blackface ewes were synchronised in mid-breeding (November; group 1; n=12 ewes) or late-breeding season (March; group 2; n=16). Anoestrous ewes (May) were treated with progestagen sponges for 7 days and then given 250 ng GnRH 3-hourly for 24 h, 2-hourly for 24 h and hourly for a further 24 h (group 3; n=12). A second group of anoestrous ewes (group 4, n=19) received three bolus injections (30 μg) of GnRH at 90-min intervals without progestagen pretreatment. After ovulation, ewes were bled twice daily until slaughter (day 4 or day 12: oestrus=day 0). Mid-breeding season (group 1) and anoestrous ewes in group 3 formed ‘adequate’ corpora lutea (CL) with high plasma progesterone levels (3–4 ng/ml) maintained for at least 12 days, and responded in vivo to ovine LH (oLH) (10 μg) with a rise in plasma progesterone on day 11 (group 3, but not group 1, ewes also responded on day 3). CL minces from these ewes responded to human chorionic gonadotrophin (hCG) in vitro with a dose-dependent increase in progesterone secretion. Ewes in group 4 had a foreshortened luteal phase (8–10 days) and low plasma progesterone levels (~1 ng/ml), consistent with formation of inadequate CL. LH injection failed to induce a significant plasma progesterone increase. Furthermore, although progesterone secretion in vitro in response to maximally stimulating doses of hCG or dibutyryl cAMP (dbcAMP) was similar to that in adequate CL, the sensitivity of these CL to hCG (EC (effective concentration)50, 1 IU hCG/ml) was reduced 10-fold compared with adequate CL (EC50, 0.1 IU hCG/ml; P<0.01). Ewes that ovulated in the late breeding season (group 2) had high plasma progesterone, although levels began to decrease after day 10. Injection of oLH in vivo increased plasma progesterone. However, sensitivity to hCG in vitro (EC50, 0.5 IU hCG/ml) was intermediate between that of adequate luteal tissue (groups 1 and 3; EC50, 0.1 IU/ml) and that of group 4 ewes (EC50, 1 IU hCG/ml). Our data demonstrate a markedly reduced luteal sensitivity to LH in vivo and hCG in vitro in Scottish Blackface ewes with inadequate CL, and suggest that a similar loss of sensitivity to LH may occur in the late breeding season.

Sign in / Sign up

Export Citation Format

Share Document