49 The dynamic changes in uterine morphology and function during the proestrus-diestrus transition in beef cattle

2021 ◽  
Vol 33 (2) ◽  
pp. 131
Author(s):  
F. A. C. C. da Silva ◽  
G. F. da Silva ◽  
B. S. Vieira ◽  
A. L. Neto ◽  
G. A. Arantes Junior ◽  
...  

In cattle, early development of the non-attaching embryo depends exclusively on the biochemical properties of the intrauterine milieu. As the embryo transitions from the oviduct to the tip of the uterine horn around 4 days after oestrus, little is known about uterine functions that modulate the milieu composition and potentially determine pregnancy success. The objective was to characterise changes in uterine luminal fluid (ULF) accumulation and absorption, endometrial vascularity, and endometrial thickness in response to progesterone fluctuations during the peri-ovulatory period in beef heifers. Fourteen Bos indicus heifers that presented a prostaglandin F2α (PGF2α) responsive CL received 500µg of PGF2α analogue i.m. (PGF) and were examined daily by rectal B-mode and pulse-wave colour-Doppler ultrasonography until the fifth day after oestrus (oestrus=Day 0). Plasma progesterone (P4) concentrations were measured daily. Uterine luminal fluid score was given based on the accumulation of fluid throughout the entire organ (0, no fluid, to 4). Measurement of the main ovarian structures, endometrial thickness, uterine luminal fluid score, and luminal fluid area of the cranial portion of the uterine horn ipsilateral to the preovulatory follicle and subsequent CL were executed by B-mode ultrasonography and endometrial vascularity by colour Doppler. The fixed effect of day was analysed by ANOVA. There was an effect of day on endometrial vascularity, endometrial thickness, and uterine luminal fluid score (P≤0.01) as well as uterine luminal fluid area (P≤0.05). Endometrial vascularity and endometrial thickness increased after PGF injection to peak on Day −1, whereas uterine fluid score peaked on Day 0. Interestingly, cranial uterine luminal fluid area peaked twice, on Day −1 and Day 5. Vascularity, thickness, and fluid accumulation decreased gradually from Day 0 to Day 5. There was a negative correlation (r=−0.55) between the sum of daily P4 concentrations during proestrus (i.e. from PGF to oestrus) and the greatest ULF score measured (P=0.05). Length of proestrus was correlated negatively (r=−0.69) with the increase in uterine body thickness during proestrus (P=0.03). The sum of daily luminal fluid scores, from PGF injection to Day 5, was double for heifers grouped within the upper third for that variable compared with those grouped within the lower third. In conclusion, peri-ovulatory transformations in uterine morphology and function are dramatic and vary in duration and in intensity among animals. Temporal changes in intraluminal fluid accumulation and absorption at the site of embryo arrival may change its biochemical composition. Potential implications for embryo receptivity and reproductive outcomes deserve further investigation.

Reproduction ◽  
2010 ◽  
Vol 139 (2) ◽  
pp. 453-463 ◽  
Author(s):  
L A Silva ◽  
O J Ginther

Colour-Doppler ultrasonography was used to study the spatial relationship between vascular perfusion in the middle of each uterine horn and the reported location of the embryo proper and expanding conceptus using endometrial vascularity scores 1–4 (nil–maximal). Vascularity increased in both uterine horns between days 14 and 18 (day 0=ovulation) in nonpregnant heifers (n=6) but not in pregnant heifers (n=11). The increase was temporally associated with decreasing plasma progesterone and increasing oestradiol. In pregnant heifers, a transient increase in endometrial vascularity in the ipsilateral horn (horn with embryo) was not detected before day 18, despite a reported transient increase in blood flow in the ipsilateral uterine artery between days 13 and 17. Endometrial vascularity in the ipsilateral horn first increased (P<0.05) between days 18 and 20. Day 20 is the reported day of adhesiveness between chorion and uterus. An increase (P<0.05) in the contralateral horn between days 18 and 22 was slight, but a greater increase occurred after day 32. Day 32 is the reported day of entry of the allantochorion into the contralateral horn. By day 42, scores were similar between the two horns, and the allantochorion reportedly fills both horns. On days 42–60, at a time when placentomes apparently are limited to the ipsilateral horn, vascularity remained elevated in the ipsilateral horn but decreased in the contralateral horn. Results support the hypothesis that vascular perfusion in each uterine horn during early pregnancy is mediated by direct contact between conceptus and uterus.


1994 ◽  
Vol 107 (11) ◽  
pp. 3165-3172 ◽  
Author(s):  
I. de Curtis ◽  
G. Gatti

Integrin alpha 6 beta 1 is a laminin receptor involved in adhesion and neurite extension of retinal neurons on laminin. The present study was carried out to identify potential interactions between the alpha 6 beta 1 receptor and cellular proteins that may be involved in integrin signaling and function. For this purpose we have used a biochemical approach based on the solubilization of retinal neurons cultured on laminin with nonionic detergents, followed by centrifugation on sucrose velocity gradients. Analysis of the distribution of the alpha 6 and beta 1 integrin subunits in the gradients showed that they migrate as a large complex after extraction of cells with octylglucoside, but not after Triton X-100 extraction. Cytoskeletal proteins known to localize in adhesion plaques did not comigrate with alpha 6 beta 1 in octylglucoside gradients, while a set of polypeptides whose tyrosine phosphorylation was enhanced by culture on laminin colocalized with alpha 6 beta 1 on the gradients after octylglucoside solubilization. Culture of retinal neurons on bovine serum albumin, a nonadhesive substratum, partially affected the gradient distribution of the receptor after octylglucoside extraction. Furthermore, analysis of the gradient distribution of two alternatively spliced isoforms of the alpha 6 subunit, alpha 6-cytoA and alpha 6-cytoB, showed that the effect of non-adhesion on the sedimentation properties of the two integrin alpha 6 isoforms was more dramatic for alpha 6-cytoB than alpha 6-cytoA. These differences in the sedimentation behaviour indicate distinct biochemical properties of the two alpha 6 isoforms that, together with previous observations on their differential distribution in the developing retina, may reflect functional specificities.


2020 ◽  
pp. 4379-4385
Author(s):  
Thomas Pap ◽  
Adelheid Korb-Pap ◽  
Christine Hartmann ◽  
Jessica Bertrand

Synovial joints are complex functional elements of the vertebrate body that provide animals with motion capabilities and hence the ability for locomotion and direct physical interaction with their environment. They are composed of different connective tissues structures that are derived from the same developmental structures in the embryo but have distinct cellular and biochemical properties. Articular cartilage and synovial membrane are key components of synovial joints and show several peculiarities that makes them different from other tissues. An in-depth knowledge of these features is important not only for understanding key features of articular function, but also providing explanations for important characteristics of both degenerative and inflammatory joint diseases. This chapter reviews the structure, biochemical composition, and function of articular cartilage and synovium, and points to important links between physiology and pathologic conditions, particularly arthritis.


QJM ◽  
2020 ◽  
Vol 113 (Supplement_1) ◽  
Author(s):  
W M Khalaf ◽  
S A Akl ◽  
R R Ramadan ◽  
M A M Kamaleldin

Abstract Background PCOS, the commonest endocrinalogical disorder affecting women of age group between 18 and 44 years. PCOS compromises fertility through various pathways as hyperandrogenism, insulin resistance and impedance of the uterine and endometrial blood flow. Metformin improves the blood flow to the endometrium through reducing androgen level and correction of insulin resistance. The commonest parameters used to detect the endometrial receptivity outcome are endometrial vascular indices. Aim of the Work to evaluate the outcome of metformin administration in anovualtory PCO patients and its effect on the endometrium, including its role in ovulation and improvement of pregnancy rates. Patients and Methods this study included 85 patients from Ain Shams University outpatient gynecology and infertility clinic during the period from January 2018 till June 2018. These patients were investigated before treatment with ultrasound on day 14, 21 to evaluate the endometrial receptivity parameters such as endometrial thickness, uterine artery vascularity, endometrial and subendometrial vascularity. The patients received metformin 500mg three times per day for three months. After this duration they were reevaluated by ultrasound at days 14, 21 to detect any improvement. Results metformin therapy resulted in a significant increase of endometrial thickness and had a significant effect on uterine RI and PI. On the endometrial level, the endometrial and subendometrial R.I and P.I were significantly reduced after metformin treatment indicating better blood flow. Conclusion Metformin therapy improves endometrial vascularity, in addition to increasing endometrial thickness and improved impedance observed in uterine artery flow.


2005 ◽  
Vol 17 (7) ◽  
pp. 693 ◽  
Author(s):  
Sharon E. Mitchell ◽  
John J. Robinson ◽  
Margaret E. King ◽  
Lynda M. Williams

In sheep, inflammation not only functions in cervical dilation at parturition, but also plays an important part in the non-pregnant ewe cervix, as demonstrated by the high level of expression of interleukin (IL)-8 at oestrus. Ewes artificially induced to ovulate have significantly lower levels of IL-8 gene expression at oestrus compared with natural oestrus, indicating an inhibition of inflammation and function, offering an explanation for the low rates of conception in vaginally inseminated synchronised ewes. To identify potential pro-inflammatory agents to combat the anti-inflammatory effects of hormonal synchronisation of oestrus, we have investigated the role of proteinase-activated receptor (PAR)-1 and PAR-2. To localise and measure the level of expression of these receptors, ovine-specific probes were derived for PAR-1 and PAR-2 and used for quantitative in situ hybridisation in the ovine cervix. Both PAR-1 and PAR-2 were expressed in the luminal epithelium of the cervix throughout the oestrous cycle, with expression being highest at oestrus. The gene expression of PAR-2 at oestrus was approximately 30% higher than that of PAR-1. Artificial synchronisation of oestrus by either an intravaginal progesterone sponge or prostaglandin F2α injections did not inhibit PAR-1 or PAR-2 expression at oestrus; rather, in the case of PAR-2, progesterone synchronisation increased it. Both synchronising procedures increased the expression of PAR-1 and PAR-2 during the luteal phase of the cycle. Therefore, agonists of PAR-1 and PAR-2 may be potentially useful pro-inflammatory agents countering the inhibition of inflammation by hormonal synchronisation.


2016 ◽  
Vol 28 (2) ◽  
pp. 184
Author(s):  
M. Pelizzari ◽  
A. Tribulo ◽  
J. Garzon ◽  
B. Bernal ◽  
R. Tribulo ◽  
...  

A retrospective analysis of factors that affect pregnancy rates from 4214 fresh in vitro-produced (IVP) embryos that were transferred at a fixed-time (FTET) in 20 different farms. Recipients were all cycling cows or heifers that were synchronized with 1 of 3 treatments: 1) treatments with progesterone (P4) devices and 2 mg of oestradiol benzoate (EB) on Day 0 (day of insertion) and 24 h after device removal (Day 8); 2) treatments with P4 devices and EB on Day 0, but with 0.5 mg of oestradiol cypionate (ECP) at device removal (Day 8); or 3) treatments with P4 devices and GnRH on Day 0 and a second GnRH 60 h after device removal (Day 5). Cows in all treatment groups also received 500 µg of cloprostenol (prostaglandin F2α) at the time of P4 device removal and 400 IU of eCG either at device removal or 3 days before device removal. All embryos were transferred 7 or 8 days after the expected time of oestrus (24 h after EB, 48 h after ECP or at the time of the second GNRH for each synchronization treatment, respectively). On the day of embryo transfer, recipients were examined by ultrasonography and those with corpus luteum >14 mm in diameter received a fresh, IVP embryo in the uterine horn ipsilateral to the corpus luteum. Pregnancy rates were determined by ultrasonography 35 days after FTET. Data were analysed by logistic regression. Independent variables were classified into the following three categories. 1) Factors related to the recipient and the environment; there were no significant differences in pregnancy rates for corpus luteum diameter (≥14 and <16 mm, ≥16 and <18 mm, or ≥18 mm; P = 0.46), number of corpus luteum (1 or ≥2; P = 0.26), and category of recipient (cow or heifer; P = 0.21). However, there were significant effects of farm (P = 0.01) and body condition score (BCS; P = 0.01). Cows with BCS ≥4.5 (1 to 5 scale) resulted in lower pregnancy rates (4/20, 20.0%) than those with BCS 2 (74/225, 32.9%), 2.5 (502/1434, 35.0%), 3 (570/1467, 38.9%), 3.5 (193/532, 36.3%), and 4 (44/118, 37.3%). 2) Factors related to the synchronization treatment; there were no significant differences between recipients receiving eCG at device removal (84/209, 40.2%) or 3 days before device removal (874/2291, 38.1%; P = 0.35). However, recipients synchronized with P4 devices and ECP had higher (P = 0.01) pregnancy rates (232/483, 48.0%) than those treated with EB (679/1888, 36.0%) or gonadotropin-releasing hormone (47/129, 36.4%). 3) Factors related to the embryo transfer technique; day of the recipient’s oestrous cycle (P = 0.36), stage of embryo transferred (IETS stages 6 or 7; P = 0.62), and operator (P = 0.57) did not affect pregnancy rates. However transfers made in the anterior third of the uterine horn resulted in higher (649/1545, 42.0%) pregnancy rates than those in the mid-third (845/2511, 33.6%) or in the distal third (6/35, 17.1%; P = 0.01). It was concluded that factors related to the recipient and the environment (farm and BCS), the synchronization treatment (ECP), and the embryo transfer technique (site of deposition) affect pregnancy rates in recipients of embryos produced in vitro and transferred at a fixed time.


2019 ◽  
Vol 31 (1) ◽  
pp. 134
Author(s):  
L. M. S. Simões ◽  
E. A. Lima ◽  
A. P. C. Santos ◽  
R. E. Orlandi ◽  
M. P. Bottino ◽  
...  

The objective was to determine the incidence of false-positive pregnancy diagnosis following the use of colour Doppler ultrasonography 20 and 22 days after fixed-time AI (FTAI) in Bos indicus heifers submitted to resynchronization 14 days after first FTAI. In the study, 512 Nellore heifers at 24.5±0.8 months of age and body condition score of 3.4±0.1 were used beginning 14 days after FTAI. On Day 14, heifers received 50mg of short-acting progesterone (Afisterone®, CEVA, São Paulo, Brazil) and a progesterone device (Prociclar®, CEVA). Eight days later (Day 22), the progesterone device was removed. A duplex B-mode (grayscale) and pulse-wave colour Doppler ultrasound instrument (M5, Mindray, Shenzhen, China) equipped with a multifrequency linear transducer was used for the examination of luteal blood flow on Days 20 and 22. The percentage of luteal area with colour Doppler signals of blood flow at each examination was determined as previously described (Ginther 2007) and was classified as low [corpus luteum (CL) with less than 25% vascularized area], intermediate (CL with 25-75% vascularized area), or high (CL with more than 75% vascularized area). Heifers with intermediate and high luteal blood flow were diagnosed as pregnant by Doppler ultrasonography, and heifers with low luteal blood flow were diagnosed as nonpregnant. Heifers diagnosed as pregnant by Doppler ultrasonography were examined 30 days after FTAI by B-mode ultrasound examination for pregnancy diagnosis and to determine the number of false positives (heifers pregnant by Doppler ultrasonography and nonpregnant by B-mode ultrasonography). Statistical analysis was performed by the GLIMMIX procedure of SAS (SAS Institute Inc., Cary, NC, USA). Pregnancy rate by Doppler ultrasonography [Day 20=60.5% (310/512), Day 22=55.3% (283/512); P=0.10] and false-positive percentage [Day 20=29.7% (92/310), Day 22=23.0% (65/2830); P=0.06] were similar on pregnancy diagnoses by Doppler ultrasonography performed 20 and 22 days after FTAI. Furthermore, in the period from 20 to 22 days after FTAI, luteolysis was verified in 5.8% (30/512) of heifers. In conclusion, anticipation of pregnancy diagnosis in 2 days by evaluation of luteal blood flow with colour Doppler ultrasonography (20 days after FTAI) does not interfere with pregnancy rate by Doppler ultrasound and percentage of false positives in Bos indicus heifers.


2018 ◽  
Vol 30 (1) ◽  
pp. 182
Author(s):  
J. Duran ◽  
D. Argudo ◽  
S. Bravo ◽  
C. Soria ◽  
G. Guevara ◽  
...  

Recipient handling during embryo transfer (ET) induces prostaglandin F2α (PGF2α) production in 2 periods: an early transient and rapid increase around the time of ET, followed by another 2 to 4 h later. This PGF2α is associated with embryonic loss during early gestation by affecting both the embryo and the corpus luteum. To control this, antiprostaglandins such as flunixin meglumine (FM) have been applied IM at the time of ET with varying results. In such studies, the interaction of IM administration of FM and difficulty of transfer has not always been evaluated, possibly confusing the interpretation of the results. Furthermore, IV FM injection at ET and its relationship with pregnancy rates (PR) has not been determined. The objectives were (1) to determine the relationship between difficulty of ET and PR; and (2) to evaluate the efficacy of IM v. IV FM on pregnancy outcomes. One hundred and ten crossbred (Bos taurus × Bos indicus) heifers (18-24 months old) from 3 farms were used as recipients. Two evaluation systems of ET difficulty were used: (1) duration of transfer (objective determination of the elapsed time measured in seconds between the introduction of the catheter and embryo release), and (2) level of difficulty experienced by the practitioner (subjective determination; 1 = minimum and 2 = medium to extreme manipulation). Quality 1 and 2 fresh embryos from superovulated cows were transferred by the same practitioner. At ET, recipients were randomly divided into 3 groups: (1) Control (no treatment, n = 31); (2) FM-IM (n = 39): injected IM with 2.2 mg kg−1 FM at ET; and (3) FM-IV (N = 40): injected with 2.2 mg kg−1 FM IV at ET. Pregnancy was diagnosed at 30 to 40 and 60 to 90 days after ET. Spearman’s test was performed to determine the correlation between duration and difficulty at ET and Chi-square test was used to compare PR. The mean duration of transfer for all heifers was 62.3 ± 57.5 s (11 to 357 s; median: 44.5 s). There was a high correlation (0.8; P < 0.001) between the ET difficulty evaluation systems. Overall, ET difficulty 1 had higher PR than ET difficulty 2 (64.2 v. 40.7; P = 0.013). The PR was significantly improved (P < 0.01) in the FM-IV group (75 and 70% at 30 and 60 days after ET) compared with control (45.2 and 32.3%) and FM-IM (33.3 and 30.7%). In conclusion, results indicate that the difficulty of transfer affects PR achieved following the transfer of in vivo-derived bovine embryos. Treatment with FM-IV following transfer resulted in significantly higher PR compared with control and FM-IM recipients. The IV injection of FM may antagonize the very early and transient increase of PGF2α caused by genital tract manipulation (even gently performed) at embryo transfer. Further research is necessary to confirm the results of the present study.


2018 ◽  
Vol 30 (1) ◽  
pp. 208
Author(s):  
J. G. Soares ◽  
F. M. Morato ◽  
G. F. Rossi ◽  
B. M. Bayeux ◽  
A. S. Oliveira ◽  
...  

The present study aimed to evaluate the effect of the follicular population from cull Nelore (Bos indicus) on the kinetics of in vitro embryonic development. At random stages of the oestrous cycle (Day –5), a total of 28 cull Nelore cows were synchronized with an intravaginal progesterone device associated with oestradiol benzoate (2.0 mg IM). At the same moment, a dose of prostaglandin F2α (2.0 mg im) was also administered to promote luteolysis and absence of corpus luteum (CL) at the time of ovum pick-up (OPU). Five days later (Day 0), all cows underwent an OPU session and the recovered oocytes were submitted to in vitro embryo production (IVEP). The same procedures were repeated 2 times at 30-day intervals (Day 25 and Day 55). Semen from a single batch of a previously tested bull was used for all IVEP. Blastocyst production and hatching were verified on Days 7, 8, and 9 of the IVEP. Data were analysed by the GLIMMIX procedure of SAS 9.3® (SAS Institute Inc., Cary, NC, USA). Data of the 3 OPU sessions were grouped and the cows were classified into 3 categories according to the follicular population: Low (19.7 ± 0.9 follicles, n = 27), Medium (33.5 ± 0.8 follicles, n = 29), and High (58.7 ± 3.2 follicles, n = 28). The Low category had a lower rate of viable oocytes [(number of viable oocytes/total number of oocytes) × 100; 62.0 v. 69.5%; P = 0.02] and cleavage rate [(number of cleaved/total number of oocytes) × 100; 55.9 v. 66.8%; P = 0.001] than the High category. The blastocyst formation rate [number of blastocysts/total number of oocytes) × 100] on Day 7 and Day 8 was lower for Low and Medium compared with the High category (Day 7: 26.1b v. 29.0b v. 35.1a %; P = 0.001; and Day 8: 29.2b v. 30.2b v. 34.7a %; P = 0.05). No differences were found in blastocysts rate on Day 9 among Low, Medium, and High categories (14.1 v. 15.9 v. 16.2%; P = 0.61). However, Low category had a lower percentage of hatched blastocysts [(number of hatched blastocysts/number of blastocysts) × 100] on Day 7 compared with High category (2.9 v. 12.0%; P = 0.01). These results reported that cull Nelore with High follicular population showed higher rates of embryo production and hatched blastocysts compared with cows with Low follicular population. We concluded that the kinetics of in vitro embryonic development was compromised in cull Nelore (Bos indicus) with low follicular population submitted to OPU-IVEP. This research was supported by Fapesp 2012/50533–2 (GIFT).


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