scholarly journals Relationship Between Seasonal Plasma Estradiol-17β and Testosterone Levels and In Vitro Production by Ovarian Follicles of Amago Salmon (Oncorhynchus rhodurus)

1983 ◽  
Vol 29 (2) ◽  
pp. 301-309 ◽  
Author(s):  
Hirohiko Kagawa ◽  
Graham Young ◽  
Yoshitaka Nagahama
2005 ◽  
Vol 17 (7) ◽  
pp. 701 ◽  
Author(s):  
K. M. Morton ◽  
S. L. Catt ◽  
W. M. C. Maxwell ◽  
G. Evans

The production of embryos from prepubertal lambs is inefficient, partly resulting from the low developmental competence of prepubertal lamb oocytes, and partly because a high proportion of lambs fail to respond to hormone stimulation. The development of a hormone stimulation regimen that all lambs respond to would increase the efficiency of breeding from prepubertal animals. Using a hormone stimulation regimen consisting of oestradiol benzoate (50 µg), a norgestomet implant (1.5 mg), pregnant mare serum gonadotrophin (400 IU) and follicle stimulating hormone (130 mg) all lambs (n = 19) responded to hormone stimulation. Uterine and ovarian weight ranged from 2.8 to 7.2 g (11.8 ± 0.7 g) and from 1.7 to 54.1 (12.5 ± 2.9 g), respectively. The number of ovarian follicles and oocytes recovered ranged from 20.0 to 500.0 (118.2 ± 29.2) and from 13.0 to 455.0 (82.0 ± 24.2), respectively, and oocytes suitable for in vitro production were obtained from all 19 lambs. Uterine weight was related to both bodyweight and growth rate (P < 0.05), although ovarian weight and the number of ovarian follicles were not related to either bodyweight or growth rate. Oocyte cleavage varied between hormone-stimulated lambs (0.0–93.0%; P < 0.05), and 484/775 (62.2%) of the oocytes cultured cleaved. Oocytes from 17 of the 19 lambs (89.5%) developed to the blastocyst stage in vitro, and the proportion of zygotes forming a blastocyst (by Day 7) ranged from 0.0 to 66.7% for individual lambs. Overall, 33.9% of zygotes (n = 164) developed to the blastocyst stage, producing 8.6 ± 2.8 blastocysts per lamb.


2019 ◽  
Vol 11 (10) ◽  
pp. 231 ◽  
Author(s):  
Bárbara Letícia Marchi da Silva ◽  
Paulo Roberto Adona ◽  
Samuel Guemra ◽  
Paulo Sergio Monzani ◽  
Moysés dos Santos Miranda

Cows treated with single doses of follicle stimulating hormone (FSH) and ovum pick up (OPU) after 24 hours were evaluated for oocyte recovery, in vitro production of embryos (IVPE), and transferred embryos. To begin evaluations, the ovarian follicles larger than three millimeters in diameters were removed from all cows used in the study. Two days after OPU, 200 milligrams of FSH was given in a single dose in 6 cows (treated). Twenty-four hours after application of FSH, the cows underwent a new OPU session for oocyte retrieval. These procedures were repeated three consecutive times without interval. In control (FSH-free) cows the OPU were performed at intervals of one week or oocyte retrieval. The viable oocytes were submitted to IVPE, and the blastocysts were transferred to the recipients. The mean number of oocytes did not differ (p &gt; 0.05) between control cows (12.1&plusmn;2.8) and those treated (10.9&plusmn;1.6). There were also no differences (p &gt; 0.05) in the number (6.6&plusmn;1.7 and 7.1&plusmn;0.9, respectively) or in the percentage (54.4&plusmn;3.3 and 64.5&plusmn;3.1%, respectively) of viable oocytes between control cows and those treated. The percentage of IVPE and pregnancy did not differ (p &gt; 0.05) between control cows (39.8&plusmn;2.6% and 44.7&plusmn;4.8%) and those treated (37.8&plusmn;2.5% and 39.5&plusmn;4.1%), respectively. The treatment with single doses of FSH did not significantly alter the evaluated results for oocyte recovery, IVPE and transferred embryos, and, therefore, did not promote significant improvements for the IVPE as a whole.


1964 ◽  
Vol 47 (2) ◽  
pp. 306-313 ◽  
Author(s):  
Denis Gospodarowicz

ABSTRACT Incubation in vitro of rabbit follicles in separate experiments with dehydroepiandrosterone-14C (DHEA-14C), progesterone-14C and pregnenolone-3H in the presence of FSH gave the following results: 39 % of the radioactivity of DHEA-14C is converted to androstenedione and testosterone, while only 3 % of the radioactivity of either progesterone-14C or pregnenolone-3H is found in the androgen fraction. From the ratio of testosterone to androstenedione formed from the three precursors, the results are interpreted to mean that DHEA and pregnenolone, and not progesterone, are precursors of androgens in the follicle.


1984 ◽  
Vol 107 (3) ◽  
pp. 395-400 ◽  
Author(s):  
Itaru Kojima ◽  
Etsuro Ogata ◽  
Hiroshi Inano ◽  
Bun-ichi Tamaoki

Abstract. Incubation of 18-hydroxycorticosterone with the sonicated mitochondrial preparation of bovine adrenal glomerulosa tissue leads to the production of aldosterone, as measured by radioimmunoassay. The in vitro production of aldosterone from 18-hydroxycorticosterone requires both molecular oxygen and NADPH, and is inhibited by carbon monoxide. Cytochrome P-450 inhibitors such as metyrapone, SU 8000. SU 10603, SKF 525A, amphenone B and spironolactone decrease the biosynthesis of aldosterone from 18-hydroxycorticosterone. These results support the conclusion that the final reaction in aldosterone synthesis from 18-hydroxycorticosterone is catalyzed by an oxygenase, but not by 18-hydroxysteroid dehydrogenase. By the same preparation, the production of [3H]aldosterone but not [3H]18-hydroxycorticosterone from [1,2-3H ]corticosterone is decreased in a dose-dependent manner by addition of non-radioactive 18-hydroxycorticosterone.


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