Effects of a superovulatory dose of pregnant mare serum gonadotropin on follicular steroid contents and oocyte maturation in rats

Yun, Young Won; Yu, Frank H.; Yuen, Basil Ho; Moon, Young Soo

doi:10.1002/mrd.1120230306

Cited by 20 publications

(22 citation statements)

References 23 publications

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“…[24][25][26] However, superovulatory treatment with PMSG markedly increased the proportion of abnormal-appearing oocytes, and caused premature or asynchronous nuclear maturation of superovulated oocytes, as compared with physiologically ovulated oocytes. 10,11,22,27) In this study, the treatments with Korean ginseng saponins to the immature rat superovulated with PMSG in early, middle and late follicular phase reduced excessive ovulatory response. Especially, GPD and Gin-Rb 1 treatments substantially decreased ovulatory response which was still higher than physiological ovulatory response reported early.…”

Section: Discussionmentioning

confidence: 79%

“…Especially, GPD and Gin-Rb 1 treatments substantially decreased ovulatory response which was still higher than physiological ovulatory response reported early. 4,10) Korean ginseng saponin treatments following PMSG administration greatly decreased the proportion of abnormal oocytes recovered from the superovulated rat. In addition, these treatments decreased the incidence of meiotically aberrant superovulated oocytes caused by a superovulatory dose of PMSG.…”

Section: Discussionmentioning

confidence: 96%

“…The current results of atypical ovulations of superovulated oocytes with a high proportion of gross abnormality and with prematurity and asynchrony of nuclear maturation following a superovulatory dose of PMSG confirm our previous reports. 10,22) In contrast to the control regimen which typically exhibited the deterioration of oocyte quality, Korean ginseng saponin treatments resulted in not only a conspicuous increase in the proportion of oocyte normalcy, but also the synchronization of oocyte nuclear maturation: a predominant decline in the percentage of superovulated oocytes arrested at prophase I and an increase in the proportion of oocytes that were in metaphase II at ovulation. This observation of the present study could suggest that Korean ginseng saponins repair the detrimental effects of superovulation on oocyte quality following a high dose of PMSG.…”

Section: Discussionmentioning

confidence: 96%

“…The recovered oocytes were counted under a stereo dissecting microscope (40ϫmagnification), and assessed for the occurrence of fragmentation and other degenerative changes as described previously. 8,10,22) Those showing fragmentation, parthenogenesis, irregular shape or amorphous opaque mass of vitelline material and empty zona pellucida were classified as abnormal.…”

Section: Modulating Effects Of Korean Ginseng Saponins On Ovarian Funmentioning

confidence: 99%

“…[6][7][8][9] Major defects following superovulatory treatment with PMSG could occur in the process of follicular development and oocyte maturation by hyperstimulation of PMSG on ovarian tissues because of prolonged biochemical action of PMSG that has long half-life. 10,11) Hyperstimulation of PMSG on ovarian tissues also induced atypical ovulation of abnormal follicles that would not ovulate and regress under a regular estrous cycle. [11][12][13] However, the precise mechanisms of these negative aspects exerted by superovulatory treatment are not fully understood.…”

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confidence: 99%

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Modulating Effects of Korean Ginseng Saponins on Ovarian Function in Immature Rats

Lee

Nam

et al. 2003

Biological & Pharmaceutical Bulletin

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Superovulation induction with exogenous gonadotropins such as pregnant mare serum gonadotropin (PMSG) and human menopausal gonadotropin (hMG) is a well-established practical technique. The purpose of this technique is to achieve enhanced commercial production of genetically meritorious individuals in the livestock industry, to retrieve a number of oocytes and early embryos in various research fields including genetic engineering, and to treat medically diverse types of female infertility in human. In spite of these advantages, the results obtained from its application on large domestic and small laboratory animals generally appear very disappointing. [1][2][3][4][5] In immature rats, administration of superovulatory doses of PMSG leads to a great reduction in fertilization rates, a substantial loss and degeneration of preimplantation embryos, and a partial or complete failure of implantation. [6][7][8][9] Major defects following superovulatory treatment with PMSG could occur in the process of follicular development and oocyte maturation by hyperstimulation of PMSG on ovarian tissues because of prolonged biochemical action of PMSG that has long half-life.10,11) Hyperstimulation of PMSG on ovarian tissues also induced atypical ovulation of abnormal follicles that would not ovulate and regress under a regular estrous cycle. [11][12][13] However, the precise mechanisms of these negative aspects exerted by superovulatory treatment are not fully understood.Ginseng has been regarded as one of the important remedies in oriental medicine for one thousand years. A review of classical oriental medicine literature showed that ginseng improves the functions of almost all the organs in the body, including reproductive organs.14) It has been sound that the most effective components in ginseng are saponins including ginsenosides which are plant glycosides having a triterpenoid dammarane skeleton as an aglycone, with three sites called R 1 , R 2 and R 3 for ester bonding with the glycones : glucose, rhamnose, xylose and arabinose.15) The specific structure of ginsenosides, a triterpenoid dammarane skeleton, is quite similar to that of ovarian steroid hormones, namely, cyclopentanoperhydrophenanthrene nucleus, implying that ginsenosides are biochemically active substances and that they act as functional ligands in steroid related reproductive organs.15) Recently, the action mechanisms of various ginsenoside fractions have been elucidated in many laboratories. For example, the fractions ginsenoside-Rg 1 , -Rh 1 and -Rh 2 exert, via glucocorticoid receptor, their biological actions which are to have glucocorticoid-response gene expressed, and/or to stimulate specific cell differentiation. [15][16][17] However, there is scarcely any available data on the effects of ginseng components on the male or female reproductive system. It has been reported in clinical medicine that in mildly infertile men Korean ginseng components stimulated spermatogenesis and enhanced spermatozoa motility.18) In addition, in menopausal sterile women, the in...

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Section: Discussionmentioning

confidence: 79%

Section: Discussionmentioning

confidence: 96%

Section: Discussionmentioning

confidence: 96%

Section: Modulating Effects Of Korean Ginseng Saponins On Ovarian Funmentioning

confidence: 99%

mentioning

confidence: 99%

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Modulating Effects of Korean Ginseng Saponins on Ovarian Function in Immature Rats

Lee

Nam

et al. 2003

Biological & Pharmaceutical Bulletin

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Effects of hyperstimulation with gonadotrophins and age of females on oocytes and their metaphase II status in rats

Tain

Goh

2000

Mol. Reprod. Dev.

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The present study was undertaken to evaluate the effects of hyperstimulation and aging on the number and proportion of oocytes in the metaphase II stage in female Wistar rats. It explored the validity of the hypothesis that a combination of hyperstimulation with pregnant mare serum gonadotrophins (PMSG) and age could compromise, to a greater extent, the oocyte quality as indicated by the proportion of ovulated oocytes in the metaphase II stage. Female Wistar rats were stimulated with varying doses of PMSG and human chorionic gonadotrophins (hCG) and the number and proportion of ovulated oocytes in the metaphase II stage were examined and compared between different groups of young adult (8–10 weeks old) and aging (30–32 weeks old) female rats. While spontaneous ovulation occurred in all young adult rats, only 50% of the aging rats did. The ovulation rate in aging rats was increased from 50 to 93% when non‐PMSG‐stimulated rats were given a dose of 10 IU of hCG at proestrus. The lower number of ovulated oocytes noted, even in those hyperstimulated with high doses of PMSG/hCG, also indicated a reduction in fertility in aging rats. Under the influence of high doses of PMSG, all aging rats ovulated, but as with the young adult rats, a higher dose of hCG was needed to achieve the maximum number of ovulated oocytes from the PMSG‐induced expanded pool of preovulatory follicles. However, the average number of ovulated oocytes in aging rats was, nevertheless, still significantly lower than in young adult rats even when approximation of weight was considered. No consistent significant difference in proportion of normal oocytes was noted within groups and between young adult and aging rats. A lower proportion of ovulated oocytes was arrested at the metaphase II stages when rats, whether they were young adult or aging, were hyperstimulated with 40 IU of PMSG. However, this proportion was restored to normal (about 100%) when a higher dose of hCG, which is a signal responsible for initiating oocyte maturation, was used. Results of the present study showed that there appears to be an age‐related reduction of sensitivity of the preovulatory follicles to the ovulation induction signal of hCG and thus higher doses of hCG were needed to ovulate the PMSG‐induced expanded pool of dominant follicles. In older rats, apart from the obvious depletion of the pool of follicles, the evidence from the present study suggests that some of these older rats do have follicles, but that these were unable to develop to preovulatory follicles, probably because of the absence of sufficiently high levels of gonadotrophins essential for the initiation of folliculogenesis. PMSG‐hyperstimulation can affect nuclear maturation; the proportion of ovulated oocytes not arrested at the metaphase II stage was higher. However, the proportion of ovulated oocytes at the metaphase II was restored to normal by increasing the dose of hCG use. Hence, meiotic aberration in rats is not age‐dependent but rather dependent on the amplitude of the luteinizing hormone...

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In vitro fertilization of Siberian hamster oocytes

Parkening

1990

J. Exp. Zool.

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Siberian hamsters were superovulated and various media were tested in an effort to fertilize the recovered oocytes in vitro. The highest percentage of fertilized ova was achieved by using a modified Tyrode's medium, designated MT (Bavister, J. Reprod. Fertil., 18:544-545, '69), previously formulated to fertilize Syrian hamster ova in vitro. Spermatozoa incubated in this medium in a concentrated state overnight (14 hr) and then diluted (1 hr) fertilized 39% of the ova. Similar results (40%) were obtained with this medium by adding 20% human follicular fluid to fresh concentrated sperm for 30 min and then diluting the sperm for 2-3 hr prior to the addition of ova. Ova fertilized in vitro cleaved to the two-cell stage but failed to develop any further in culture. Two-cell embryos recovered from mated hamsters and cultured did not undergo additional cleavage. Four-cell embryos collected from mated females and cultured cleaved to the six- to eight-cell stage and stopped. Techniques and media used for fertilizing large numbers of Syrian and Chinese hamster ova in vitro will have to be modified to achieve the same degree of success in the Siberian hamster.

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Effects of a superovulatory dose of pregnant mare serum gonadotropin on follicular steroid contents and oocyte maturation in rats

Cited by 20 publications

References 23 publications

Modulating Effects of Korean Ginseng Saponins on Ovarian Function in Immature Rats

Modulating Effects of Korean Ginseng Saponins on Ovarian Function in Immature Rats

Effects of hyperstimulation with gonadotrophins and age of females on oocytes and their metaphase II status in rats

In vitro fertilization of Siberian hamster oocytes

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