103 Effects of administration of human chorionic gonadotrophin at Day 5 post-ovulation on development of the original corpus luteum depend on the locational relationship between the original and accessory corpora lutea
| Autor: | S. Haneda, K. Hazano, M. Matsui |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Estrous cycle
endocrine system urogenital system media_common.quotation_subject Ovary Reproductive technology Biology Luteal phase Andrology Endocrinology Controlled internal drug release medicine.anatomical_structure Reproductive Medicine Genetics medicine Animal Science and Zoology Folliculogenesis Molecular Biology Ovulation Corpus luteum reproductive and urinary physiology hormones hormone substitutes and hormone antagonists Developmental Biology Biotechnology media_common |
| Zdroj: | Reproduction, Fertility and Development. 32:177 |
| ISSN: | 1031-3613 |
| Popis: | In cattle, human chorionic gonadotrophin (hCG) is administered at Day 5 post-ovulation to improve fertility. This treatment can induce ovulation of the first-wave dominant follicle (W1DF), from which an accessory corpus luteum (CL) is generated. In addition, hCG has the effect of promoting CL development. It is possible that the locational relationship between the original and accessary CLs influences the effect of hCG on CL development, because the locational relationship of the CLs affects intraovarian blood flow. The present study aimed to clarify whether the locational relationship between the original and accessory CLs influences the effect of hCG on their development. Cross-bred beef heifers (Holstein×Japanese Black, n=56) were used for the present study. The oestrus cycle was synchronized using oestradiol benzoate (EB) and a controlled internal drug release (CIDR)-based program. Briefly, an administration of EB (2mg) with 9-day CIDR insertion was followed by administration of prostaglandin F2a analogue (PGF2a) on the day of CIDR removal, EB (1mg) 1 day after a PGF2a injection, and GnRH 12h after the second EB injection. At Day 5 post-ovulation, the locational relationship between the original CL and the W1DF was confirmed using transrectal ultrasonography (USG), and two groups were defined: ipsilateral group (IG; n=30), in which the CL and the W1DF are in the same ovary, and contralateral group (CG; n=26), in which the CL and the W1DF are in separate ovaries. Moreover, IG and CG were respectively subdivided into two groups, with or without hCG (1500IU) treatment (IG/hCG, n=15; IG without hCG, n=15, and CG/hCG, n=14; CG without hCG, n=12). The diameter and luteal tissue area (i.e. minus the cavity area) of the original CL and the accessory CL were examined at Days 5, 7, and 14, using USG. Two-way repeated-measures ANOVA was used to compare the diameter and luteal tissue area between IG/hCG and IG without hCG, and between CG/hCG and CG without hCG. In CG, the diameter (P |
| Databáze: | OpenAIRE |
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