Hepatic steroid inactivating enzymes, hepatic portal blood flow and corpus luteum blood perfusion in cattle

Abstract

Contents Production from the corpus luteum (CL) and/or hepatic steroid inactivation impacts peripheral concentrations of P4, which can alter reproductive performance. Our primary objective was to examine hepatic steroid inactivating enzymes, portal blood flow, and luteal blood perfusion at 10 days post‐insemination in pregnant versus non‐pregnant beef and dairy cows. Twenty early lactation Holstein cows and 20 lactating commercial beef cows were utilized for this study. At day 10 post‐insemination, hepatic portal blood flow and CL blood perfusion were measured via Doppler ultrasonography. Liver biopsies were collected and frozen for later determination of cytochrome P450 1A (CYP1A), 2C (CYP2C), 3A (CYP3A), uridine diphosphate‐glucuronosyltransferase (UGT) and aldo‐keto reductase 1C (AKR1C) activities. Pregnancy was determined at day 30 post‐insemination and treatment groups were retrospectively assigned as pregnant or non‐pregnant. Data were analyzed using the mixed procedure of SAS. Steroid metabolizing enzyme activity was not different (p > .10) between pregnant versus non‐pregnant beef or dairy cows. Hepatic portal blood flow tended (p < .10) to be increased in pregnant versus non‐pregnant dairy cows. Luteal blood perfusion was increased (p < .05) in pregnant versus non‐pregnant dairy cows. Pregnant dairy cows appear to have an increased rate of hepatic clearance of P4 in combination with increased synthesis from the CL. This could account for the lack of difference in peripheral P4 concentrations between pregnant and non‐pregnant dairy cows. This study highlights the relevance of further investigation into steroid secretion and inactivation and their impact on the maintenance of pregnancy in cattle.

Relationship between ovarian ultrasonographic findings on the seventh post-estrus day and plasma progesterone concentration, nutritional metabolic factors, and pregnancy outcome in dairy cows

“…In ultrasonography, luteal size is commonly measured because it correlates with plasma P 4 concentration [ 13 ]. Additionally, measurement of the size of the first-wave dominant follicle (DF) [ 14 ] and, more recently, measurement of luteal blood flow using color Doppler ultrasonography have also been performed [ 15 , 16 , 17 , 18 , 19 ]. First-wave DF has been reported to secrete estradiol (E 2 ) [ 20 ] and may negatively affect fertility [ 14 ], while luteal blood flow has been reported to be higher in pregnant cows than in non-pregnant cows after artificial insemination (AI) [ 16 ] and embryo transfer (ET) [ 17 ].…”

Characterization of the Normal Portal and Hepatic Blood Flow of Adult Holstein-Friesian Cows

“…We applied the average maximum velocity method to our measurements to identify whether turbulence was attributable to a disturbed flow or tissue noise (main problem with the uniform insonation method). Different authors have used a non-corrected average maximum velocity profile method, and a correction factor of 0.57 must thus be applied to the values reported [2,7,13,14] for both Vmean and F values (which depend on the first factor). In the maximum velocity method, the Doppler spectrum is measured over a small region (referred to as “sample volume”) in the center of the vessel.…”

“…As we found no significant cardiac influence but a respiratory influence in Doppler waveform, we considered that VPI was not appropriate for characterizing the portal vein Doppler spectrum. We obtained Vmax and Vrev in addition to F and Vmean to characterize the portal and hepatic blood flow, similarly to other authors [7,13,14], and represent differences between laminar and turbulent flow (difference between Vmax, Vrev, and Vmean).…”

“…Invasive techniques have been used to study hepatic hemodynamics [1,3,4,5,6]. However, more recently, Doppler ultrasound has gained further importance as a non-invasive technique [2,7]. Doppler ultrasound is a non-invasively diagnostic imaging technique that has been widely used in human and veterinary medicine to characterize the blood flow associated with normal and pathological conditions of the liver or as a reflection of systemic conditions in hepatic circulation [8,9,10].…”

Biotecnologías reproductivas en el ganado bovino: cinco décadas de investigación en México

“…En uno realizado en 1995, en México, en el CEMEGEN, se encontró que el extracto crudo produjo más embriones que el purificado en bovinos productores de leche (141) . Por el contrario, en un estudio realizado en 2014, en el INIFAP, con bovinos productores de carne, el extracto purificado generó más embriones que el extracto crudo (142) ; esto puede deberse a que el metabolismo hepático de los bovinos productores de leche es más acelerado comparado con el de bovinos productores de carne (143) .…”