Effects of leptin administration on development, vascularization and function of Corpus luteum in alpacas submitted to pre-ovulatory fasting

Norambuena, M. Cecilia; Hernández, Francisca; Maureira, Jonathan; Rubilar, Carolina; Alfaro, Jorge; Silva, Gonzalo; Silva, Mauricio; Ulloa-Leal, C.

doi:10.1016/j.anireprosci.2017.04.006

Cited by 9 publications

(11 citation statements)

References 39 publications

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“…The difference in CLBF between pregnant and non-pregnant llamas was only evident after day 12 (48). Similar CLBF profiles between nonpregnant females were also observed using Doppler ultrasound in llamas (50,51), alpacas (52), and dromedaries (53,54), after inducing ovulation. In these cases, CLBF reached maximum values between 7 and 9 days after induction of ovulation and after that, they began to descend and reached basal levels between days 12 and 14.…”

Section: Figure 4 |supporting

confidence: 74%

Uterine and Corpus Luteum Blood Flow Evaluation Prior to Uterine Flushing in Llama Embryo Donors

et al. 2020

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The aim of this study was to assess the uterine blood flow (UBF) and corpus luteum blood flow (CLBF) in llamas 8 days post-mating, using color-Doppler ultrasonography (CDU), to determine the possible relationship between vascularization and the presence of an embryo. Adult females ( n = 25) were used to monitor ovarian dynamics by palpation and transrectal ultrasonography until detection of a ≥6 mm growing follicle. Females were randomly assigned to one of two groups: Group I ( n = 19), were mated and ovulation was induced by a single dose of buserelin (GnRH analog) that same day (Day 0); and Group II ( n = 6), only ovulation was induced (control). On Day 8, UBF and CLBF were evaluated transrectally in both groups. The color-flow images obtained were analyzed with Image J1.52a software to determine the vascularization area and the percentage of corpus luteum with blood flow emission (CLBF%) together with the percentage for each uterine horn (UBF%). Statistical analysis was performed using an ANOVA test. In Group I, uterine flushing was performed to obtain the embryos, thus dividing the females into Group I+ ( n = 10), when an embryo was recovered and Group I- ( n = 9), when no embryo was recovered. Embryo recovery rate was 52.63% (10/19). In Group I+, UBF% was significantly higher compared to Group I- and Group II ( P <0.05). UBF appears to be a good predictor for embryo presence, with an area under the curve (AUC) of 0.9 and an optimal cut-off value of 9.37% (with a sensitivity of 90% and specificity of 88.9%). The CLBF% did not differ between groups ( P > 0.05). In conclusion, it is possible to detect a local increase of UBF in the presence of an embryo on day 8 post-mating in llamas. This could be useful to achieve an early pregnancy diagnosis or to decide whether to carry out the uterine flushing in a llama embryo transfer program.

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Section: Figure 4 |supporting

confidence: 74%

Uterine and Corpus Luteum Blood Flow Evaluation Prior to Uterine Flushing in Llama Embryo Donors

et al. 2020

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“…Similarly, in non‐pregnant llamas, both plasma P4 and luteal vascularization increased from treatment to Day 8 after pharmacological induction of ovulation and then decreased between Days 10 and 12 (Silva et al, ; Ulloa‐Leal et al, ). Also in non‐pregnant alpacas, luteal vascularization increased after induction of ovulation, reaching its maximum values between Days 7 and 9 after GnRH analog (Gonadorelin acetate) administration and then decreased in coincidence with plasma P4 concentration (Norambuena et al, ). In different species, it has been reported that both luteal blood flow and plasma P4 concentration simultaneously decreased in non‐pregnant animals while they remained elevated or continued increasing during early pregnancy (mares: Ginther et al, ; Šichtař et al, ; cows: Herzog et al, ; Hassan et al, ; ewes: Figueira et al, ; Arashiro et al, ; goats: Balaro et al, ; Cosentino et al, ; buffaloes: Di Francesco et al, ; Vecchio et al, ).…”

Section: Discussionmentioning

confidence: 99%

“…Occurrence of ovulation was assessed 2 days after mating based on ultrasonographic visualization of the disappearance of the dominant follicle and further confirmed by P4 plasma profile. Afterwards, females were examined by transrectal doppler ultrasonography (MyLab 30 Vet Gold ESAOTE Pie medical attached to a 5.0 MHz lineal‐array electronic transducer) every other day from Day 6 until Day 18 post‐mating; in order to asses CL's diameter and vascularization, as described for several species (mare: Ginther & Utt, ; cattle: Viana et al, ; alpaca: Norambuena et al, ; llama: Silva, Urra, & Ratto, ). Briefly, to asses CL vascularization, the transducer was placed over the ovary and three seconds video clips of the CL vascularization was registered and downloaded.…”

Section: Methodsmentioning

confidence: 99%

“…Images were saved in TIFF format and analysed by imagej 1.52a software (National Institute of Health). The degree of vascularization was estimated by measuring the area of the vascular flow signals (Doppler mode) over the CL area (B‐mode) (Norambuena et al, ; Viana et al, ). Thus, per cent area of vascularization was calculated by the following equation: per cent area of vascularization = (CL vascular area/CL total area) × 100.…”

Section: Methodsmentioning

confidence: 99%

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Corpus luteum vascularization during the maternal recognition of pregnancy in llamas (Lama glama)

Gallelli

Bianchi

Zampini

et al. 2019

Reprod Domestic Animals

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The aim of this study was to characterize corpus luteum vascularization and its association with plasma progesterone concentration in early stages of pregnancy, when maternal recognition of pregnancy is expected to occur. In all animals, both plasma progesterone concentration and corpus luteum vascularization increased from Day 6 to Day 8 post‐mating and afterwards in non‐pregnant llamas they started to decrease to reach basal levels around Days 12 to 14 post‐mating, while in pregnant animals, both variables remained elevated until the end of the study. A lineal positive relationship between corpus luteum vascularization and plasma progesterone concentration was observed in pregnant (r2 = .46, p < .0001) and non‐pregnant llamas (r2 = .66, p < .0001). Pregnant animals showed higher plasma progesterone concentration and corpus luteum vascularization than the non‐pregnant ones from Day 12 post‐mating until the end of the study (p ˂ .05 and p ˂ .01, respectively). These results suggest that maternal recognition of pregnancy should occur before Day 12 post‐mating in order to expand luteal lifespan, maintaining corpus luteum vascularization and progesterone production. Also, the assessment of CL vascularization area could be a useful and non‐invasive method for early pregnancy diagnosis due to its association with plasma progesterone concentration.

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“…Wiles et al (19) have demonstrated that the addition of leptin in an in vitro culture of goats luteal cells increased the expression of angiogenic factors such as angiotensin I (Ang1), fibroblast growth factor 2 (FGF2), and vascular endothelial growth factor (VEGF). In fact, CL vascularization did increase in alpacas previously treated with leptin during follicular phase (pre-ovulatory follicle > 7 mm of diameter) and given GnRH for ovulation induction, however, CL diameter, plasma luteinizing hormone (LH), and progesterone concentration were similar between leptin and non-leptintreated females (20).…”

Section: Introductionmentioning

confidence: 92%

Effect of Different Levels of Energy Diet Restriction on Energy Balance, Leptin and CL Development, Vascularization, and Function in South American Camelids

et al. 2020

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The objective was to determine the effect of energy diet restriction on energy balance, systemic leptin and corpus luteum (CL) vascularization, development, and function in South American camelids. In experiment 1, adult llamas were randomly assigned to receive a diet of 70% of their maintenance energy requirements (MER) (Restricted group, n = 7) or fed ad libitum (Control group, n = 7) during 28 days. Body live weight (BLW) and body condition score (BCS) were recorded, blood samples were collected every 2 weeks to measure plasma leptin concentrations, and energy metabolites were quantified. In experiment 2, adult alpacas were randomly assigned to receive a diet of 40% MER for 21 days (Restricted group, n = 7) or fed ad libitum (Control group, n = 7). Then, ovulation was induced with gonadorelin acetate (day = 0), and trans-rectal ultrasonography (7.5 MHz) was performed using B and Doppler mode to record the diameter of the pre-ovulatory follicle, ovulation, CL diameter, and vascularization from Days 0 to 13. Blood samples were collected every 48 h from Days 1 to 13 to quantify plasma leptin and progesterone concentrations. In experiment 1, energy diet restriction of 70% MER did not affect plasma leptin concentration and metabolic parameters of the Restricted group. In experiment 2, the Restricted group had a lower BCS (p < 0.001), a smaller diameter of the CL on Days 5 and 7 (p < 0.05), and a smaller maximum diameter of the CL (10.2 ± 0.6 mm) than the Control group (12.1 ± 0.6 mm; p = 0.04). Low energy restriction of 70% MER for 28 days did not affect the energy balance of llamas (Experiment 1). Moderate energy restriction of 40% MER for 21 days negatively affected energy balance (BCS), and CL development but not its vascularization, leptin, and progesterone concentrations. These species must be submitted to longer periods or a higher level of energy restriction to impair ovarian function.

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Effects of leptin administration on development, vascularization and function of Corpus luteum in alpacas submitted to pre-ovulatory fasting

Cited by 9 publications

References 39 publications

Uterine and Corpus Luteum Blood Flow Evaluation Prior to Uterine Flushing in Llama Embryo Donors

Uterine and Corpus Luteum Blood Flow Evaluation Prior to Uterine Flushing in Llama Embryo Donors

Corpus luteum vascularization during the maternal recognition of pregnancy in llamas (Lama glama)

Effect of Different Levels of Energy Diet Restriction on Energy Balance, Leptin and CL Development, Vascularization, and Function in South American Camelids

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