scholarly journals 201 Factors that limit out-of-season breeding success in ewes

2019 ◽  
Vol 97 (Supplement_1) ◽  
pp. 74-74
Author(s):  
Berlin Howell ◽  
Joan M Burke ◽  
Charles Lee ◽  
Erin Wood ◽  
Charles Rosenkrans ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Pregnancy Rate ◽  
Cytochrome P450 Enzyme ◽  
Serum Concentrations ◽  
Sheep Industry ◽  
Cytochrome P450 Activity ◽  
P450 Enzyme ◽  
P450 Activity ◽  
Short Days ◽  
Body Condition Scores

Abstract The American Sheep Industry recently stressed the importance of out-of-season breeding to meet year round demand for quality lamb. Because ewes naturally breed during short days, spring breeding is a challenge. The objective was to determine factors that reduce pregnancy rate in Katahdin ewes in Arkansas. In 2017, 95 ewes (1.6 - 9.4 yr of age; mean 2.6 ± 1.8) were bred between mid-April to mid-May. Between mid-August to mid-September, 82 ewes (1.0 - 8.2 yr of age; 2.6 ± 1.7) were bred. In spring, ewes grazed endophyte-infected tall fescue, but in fall, primarily bermudagrass was available. Body weight (BW) and body condition scores (BCS), and serum concentrations of anti-mullerian hormone (AMH), prolactin, and cytochrome P450 enzyme activity were determined before rams entered. Ewes were exposed to teasers 14 d before breeding. Data were analyzed by Proc GLM and CORR (SAS) with season of breeding in model and ewe age used as covariate. Pregnancy rate was greater in fall than spring bred ewes (89.3 ± 4.0 vs. 21.9 ± 3.3%, P < 0.001). Ewes that became pregnant compared with nonpregnant had a greater concentration of AMH regardless of season bred (3.3 ± 0.22 vs. 2.4 ± 0.41 ng/mL, P = 0.04; R = 0.22, P = 0.004), but tended to have a lower concentration of prolactin (20.2 ± 2.7 vs. 30.4 ± 4.8 ng/ mL, P = 0.06; R = -0.38, P < 0.001). The overall lower prolactin in spring suggests a reduction associated with fescue toxins, but further research is necessary. Cytochrome P450 activity was not significantly lower in ewes that became pregnant compared with nonpregnant (R = -0.28, P = 0.002), and was greater in younger ewes (R = -0.25, P = 0.03). Selecting ewes more tolerant to fescue toxins may improve success of out-of-season breeding in the Southeastern United States

Effects of phenol on metabolic activities and transcription profiles of cytochrome P450 enzymes inChironomus kiinensislarvae

2015 ◽  
Vol 106 (1) ◽  
pp. 73-80 ◽  
Author(s):  
C.W. Cao ◽  
L.L. Sun ◽  
F. Niu ◽  
P. Liu ◽  
D. Chu ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Exposure Period ◽  
Open Reading Frames ◽  
Cytochrome P450 Enzyme ◽  
Cytochrome P450 Enzymes ◽  
Transcription Profiles ◽  
P450 Enzyme ◽  
Metabolic Activities ◽  
P450 Activity ◽  
Phenol Stress

AbstractPhenol, also known as carbolic acid or phenic acid, is a priority pollutant in aquatic ecosystems. The present study has investigated metabolic activities and transcription profiles of cytochrome P450 enzymes inChironomus kiinensisunder phenol stress. Exposure ofC. kiinensislarvae to three sublethal doses of phenol (1, 10 and 100 µM) inhibited cytochrome P450 enzyme activity during the 96 h exposure period. The P450 activity measured after the 24 h exposure to phenol stress could be used to assess the level (low or high) of phenol contamination in the environment. To investigate the potential of cytochrome P450 genes as molecular biomarkers to monitor phenol contamination, the cDNA of ten CYP6 genes from the transcriptome ofC. kiinensiswere identified and sequenced. The open reading frames of the CYP6 genes ranged from 1266 to 1587 bp, encoding deduced polypeptides composed of between 421 and 528 amino acids, with predicted molecular masses from 49.01 to 61.94 kDa and isoelectric points (PI) from 6.01 to 8.89. Among the CYP6 genes, the mRNA expression levels of theCYP6EW3, CYP6EV9, CYP6FV1andCYP6FV2genes significantly altered in response to phenol exposure; therefore, these genes could potentially serve as biomarkers in the environment. This study shows that P450 activity combined with one or multipleCYP6genes could be used to monitor phenol pollution.

The role of cytochrome P450 enzyme genetic variants in cannabis hyperemesis syndrome—A case report

2021 ◽  
Author(s):  
Maxim Kuzin ◽  
Franziskos Xepapadakos ◽  
Isabel Scharrer ◽  
Marc Augsburger ◽  
Chin‐Bin Eap ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Case Report ◽  
Genetic Variants ◽  
Cytochrome P450 Enzyme ◽  
P450 Enzyme ◽  
Cannabis Hyperemesis Syndrome

scholarly journals Pediatric Cytochrome P450 Activity Alterations in Nonalcoholic Steatohepatitis

2017 ◽  
Vol 45 (12) ◽  
pp. 1317-1325 ◽  
Author(s):  
Hui Li ◽  
Mark J. Canet ◽  
John D. Clarke ◽  
Dean Billheimer ◽  
Stavra A. Xanthakos ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Nonalcoholic Steatohepatitis ◽  
Cytochrome P450 Activity ◽  
P450 Activity

Inter-species comparisons of hepatic cytochrome P450 enzyme levels in male ruminants

2003 ◽  
Vol 77 (10) ◽  
pp. 555-560 ◽  
Author(s):  
Miroslav Machala ◽  
Pavel Soucek ◽  
Jir� Neca ◽  
Robert Ulrich ◽  
Jir� Lamka ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Cytochrome P450 Enzyme ◽  
P450 Enzyme ◽  
Species Comparisons ◽  
Hepatic Cytochrome

Modulation of Cytochrome P450 Activity by 18β-Glycyrrhetic Acid and its Consequence on Buspirone Pharmacokinetics in Rats

2015 ◽  
Vol 29 (8) ◽  
pp. 1188-1194 ◽  
Author(s):  
Sang-Bum Kim ◽  
Hyun-Jong Cho ◽  
Yeong Shik Kim ◽  
Dae-Duk Kim ◽  
In-Soo Yoon
Keyword(s):  
Cytochrome P450 ◽  
Glycyrrhetic Acid ◽  
Cytochrome P450 Activity ◽  
Pharmacokinetics In Rats ◽  
P450 Activity

scholarly journals Glutathione S-Transferases and Cytochrome P450 Enzyme Expression in Patients with Intracranial Tumors: Preliminary Report of 55 Patients

2018 ◽  
Vol 28 (1) ◽  
pp. 56-62
Author(s):  
Cahit Kural ◽  
Arzu Kaya Kocdogan ◽  
Gulcin Güler Şimşek ◽  
Serpil Oğuztüzün ◽  
Pınar Kaygın ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Brain Tissue ◽  
Pituitary Adenomas ◽  
Normal Brain ◽  
Cytochrome P450 Enzyme ◽  
Intracranial Tumors ◽  
Glutathione S Transferase ◽  
Normal Brain Tissue ◽  
Tissue Samples ◽  
P450 Enzyme

Objective: Intracranial tumors are one of the most frightening and difficult-to-treat tumor types. In addition to surgery, protocols such as chemotherapy and radiotherapy also take place in the treatment. Glutathione S-transferase (GST) and cytochrome P450 (CYP) enzymes are prominent drug-metabolizing enzymes in the human body. The aim of this study is to show the expression of GSTP1, GSTM1, CYP1A1, and CYP1B1 in different types of brain tumors and compare our results with those in the literature. Subjects and Methods: The expression of GSTP1, GSTM1, CYP1A1, and CYP1B1 was analyzed using immunostaining in 55 patients with intracranial tumors in 2016–2017. For GST and CYP expression in normal brain tissue, samples of a portion of surrounding normal brain tissue as well as a matched far neighbor of tumor tissue were used. The demographic features of the patients were documented and the expression results compared. Results: The mean age of the patients was 46.72 years; 29 patients were female and 26 were male. Fifty-seven specimens were obtained from 55 patients. Among them, meningioma was diagnosed in 12, metastases in 12, glioblastoma in 9, and pituitary adenoma in 5. The highest GSTP1, GSTM1, and CYP­1A1 expressions were observed in pituitary adenomas. The lowest GSTP1 expression was detected in glioblastomas and the lowest CYP1B1 expression in pituitary adenomas. Conclusion: GSTP1 and CYP expression is increased in intracranial tumors. These results should be confirmed with a larger series and different enzyme subtypes.

Drug Interactions of Macrolides: Emphasis on Dirithromycin

1997 ◽  
Vol 31 (3) ◽  
pp. 349-356 ◽  
Author(s):  
Vish S Watkins ◽  
Ron E Polk ◽  
Jennifer L Stotka
Keyword(s):  
Cytochrome P450 ◽  
Drug Interactions ◽  
Ethinyl Estradiol ◽  
Enzyme System ◽  
Cytochrome P450 Enzyme ◽  
Cytochrome P450 Enzymes ◽  
Kidney Transplant Recipients ◽  
P450 Enzyme ◽  
Cytochrome P450 Enzyme System ◽  
Clinically Significant

Objective To describe the drug interactions of dirithromycin, a new macrolide, and to compare them with those of other macrolides. Data Sources A literature search was performed using MEDLINE to identify articles published between January 1980 and July 1995 concerning the drug interactions of macrolides. Published abstracts were also examined. All studies using dirithromycin were performed under the sponsorship of Eli Lilly and Company. Data Synthesis Erythromycin, the first macrolide discovered, is metabolized by the cytochrome P450 enzyme system. By decreasing their metabolism, erythromycin can interact with other drugs metabolized by the cytochrome P450 enzymes. The lack of such interactions would be a desirable feature in a newer macrolide. We describe studies performed to detect any interactions of dirithromycin with cyclosporine, theophylline, terfenadine, warfarin, and ethinyl estradiol. The studies showed that dirithromycin, like azithromycin, is much less likely to cause the interactions detected with clarithromycin and erythromycin. A review of the literature showed differences among macrolides in their abilities to inhibit cytochrome P450 enzymes and, thus, to cause drug–drug interactions. Erythromycin and clarithromycin inhibit cytochrome P450 enzymes, and have been implicated in clinically significant interactions. Azithromycin and dirithromycin neither inhibit cytochrome P450 enzymes nor are implicated in clinically significant drug–drug interactions. Conclusions Dirithromycin, a new macrolide, does not inhibit the cytochrome P450 enzyme system. The concomitant use of dirithromycin with cyclosporine, theophylline, terfenadine, warfarin, or ethinyl estradiol was studied in pharmacokinetic and pharmacodynamic studies. In vitro, dirithromycin did not bind cytochrome P450. In healthy subjects, erythromycin increases the clearance of cyclosporine by 51%, whereas dirithromycin causes no significant changes in the pharmacokinetics of cyclosporine. In kidney transplant recipients, administration of dirithromycin was associated with a significant (p < 0.003) decrease of 17.4% in the clearance of cyclosporine. In patients taking low-dose estradiol, the administration of dirithromycin caused a significant (p < 0.03) increase of 9.9% in the clearance of ethinyl estradiol; escape ovulation did not occur. Unlike erythromycin and clarithromycin, dirithromycin had no significant effects on the pharmacokinetics of theophylline, terfenadine, or warfarin. The alterations typical of drug interactions that are based on inhibition of the cytochrome P450 system occurring with erythromycin and clarithromycin were not observed with dirithromycin.

Sign in / Sign up

Export Citation Format

Share Document