Effects of a single combined dose of pregnant mares serum gonadotrophin and human chorionic gonadotrophin on ovulation rate in young rabbits

1994 ◽  
Vol 34 (3-4) ◽  
pp. 299-305
Author(s):  
C.G. Gravance
Keyword(s):  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Ovulation Rate

Ovulation rate in ewes treated with pregnant mares' serum gonadotrophin and luteinizing hormone releasing factor

1976 ◽  
Vol 86 (1) ◽  
pp. 127-129 ◽  
Author(s):  
P. T. McGovern ◽  
J. A. Laing
Keyword(s):  
Luteinizing Hormone ◽  
Domestic Animals ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Ovulation Rate ◽  
Commercial Application ◽  
Established Procedure

Although the administration of pregnant mares' serum gonadotrophin (PMSG) to induce superovulation is a well established procedure (see Anderson, Schultz & Melampny, 1963), the unpredictability of the response to this treatment continues to impose a constraint on the commercial application of egg transfer techniques in the large domestic animals. In sheep, the additional use of human chorionic gonadotrophin (HCG) has been mainly centred on attempts to control the time of ovulation (Ortavant, Thibault & Wintenberger, 1949; Braden, Lamond & Radford, 1960; Dziuk et al. 1964; McGovern, Williams & Hancock, 1969). However, Killeen & Moore (1970) found that the proportion of follicles which rupture was increased in PMSG-treated ewes which had been given HCG at the beginning of oestrus. The purpose of the observations recorded here was to examine the possibility that a further gain in ovulation rate in PMSG-treated sheep might be obtained with the use of luteinizing hormone releasing factor (LHRF). No attempt was made to reproduce physiological levels of the releasing factor and dosage was aimed at achieving a superovulatory effect.

Induction of puberty in gilts 2. The effect of boars on maintenance of cyclic activity in gilts induced to ovulate with pregnant mare's serum gonadotrophin and human chorionic gonadotrophin

1981 ◽  
Vol 32 (1) ◽  
pp. 51-54 ◽  
Author(s):  
A. M. Paterson ◽  
D. R. Lindsay
Keyword(s):  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Ovulation Rate ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Cyclic Activity

ABSTRACTIn two experiments prepubertal gilts were injected with a combination of 400 international units pregnant mare's serum gonadotrophin and 200 international units human chorionic gonadotrophin. The gilts were housed either in contact with or isolated from mature boars. Data were obtained of ovarian activity determined immediately after gonadotrophin treatment and at the anticipated time of the second oestrus.All treated gilts ovulated in response to the treatment and 83% displayed oestrus. Ovulation rate varied both within and between experiments, in experiment 1 the range being 7 to 19 corpora lutea and in experiment 2, between 5 to >30 corpora lutea. Four distinct types of behaviour were observed at the time of the second cycle: ovulation associated with oestrus; ovulation without oestrus; oestrus but no ovulation; and a return to a prepubertal state with no oestrus or ovulation. The presence of boars enhanced the maintenance of cyclic activity. Overall, more gilts displayed a second oestrus (33/39 v. 19/41, X2 = 11·2, P<0·001), and more had a second ovulation (32/39 v. 24/41, X2=4·2, P<0·05) when boars were run with the gilts.

Hormone concentrations and ovulatory response in rats treated with antiprogestagens

1991 ◽  
Vol 129 (3) ◽  
pp. 423-429 ◽  
Author(s):  
J. Th. J. Uilenbroek
Keyword(s):  
Cumulus Cells ◽  
High Serum ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Ovulation Rate ◽  
Female Rats ◽  
Serum Prolactin ◽  
Lh Surge ◽  
Serum Lh ◽  
Preovulatory Follicles

ABSTRACT Administration of antiprogestagens (2 mg/day) to female rats for 21 days induces high serum prolactin levels. These levels stimulate luteal progesterone production and an increase in ovarian weight. Compared with RU486 (mifepristone) the increase in prolactin is less after treatment with ZK299 (onapristone), an antiprogestagen with lower antiglucocorticoid activity. To study whether cyclic ovulations occur in rats treated with antiprogestagens, 5-day cyclic rats were given daily injections of RU486 or ZK299 (2 mg) from metoestrus (day 1) to pro-oestrus. This treatment advanced the forthcoming ovulation by 1 day; however, the ovulation rate was low. Injection of 10 IU human chorionic gonadotrophin on the afternoon of pro-oestrus (day 3) increased the ovulation rate, but not to the level found in oil-treated rats. Serum LH concentrations measured from metoestrus to oestrus at 10.00 and 17.00 h were higher in antiprogestagen- than in oil-treated rats from day 2 (17.00 h) onwards. A low preovulatory LH surge was found in antiprogestagen-treated rats on the after-noon of pro-oestrus (day 3). Ovarian histology at the day of oestrus (day 4) confirmed the presence of a low LH surge as, besides ruptured follicles, unruptured follicles with dispersion of cumulus cells were present. The pro-oestrous surge of prolactin was also advanced by 24 h. The magnitude, however, was not different from that in oil-treated rats at day 4. In conclusion, daily administration of antiprogestagens to 5-day cyclic rats results in increased basal levels of serum LH and advancement of the preovulatory surge of prolactin and LH by 1 day. The ovulatory response is low due to the low pre-ovulatory surge of LH and to a reduced ability of preovulatory follicles to respond to LH. Journal of Endocrinology (1991) 129, 423–429

scholarly journals The effect of H-2 region and genetic background on hormone-induced ovulation rate, puberty, and follicular number in mice

1991 ◽  
Vol 57 (1) ◽  
pp. 41-49 ◽  
Author(s):  
J. L. Spearow ◽  
R. P. Erickson ◽  
T. Edwards ◽  
L. Herbon
Keyword(s):  
Genetic Background ◽  
Follicular Development ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Ovulation Rate ◽  
Follicular Atresia ◽  
Linked Gene ◽  
Induced Ovulation ◽  
Follicular Maturation ◽  
Timing Of Puberty

SummaryWe have examined the effects of major histocompatibility (H-2) haplotypes and genetic background (all loci other than the H-2 region) on hormone-induced ovulation rate in congenic strains of mice. In comparison with the H-2a haplotype, the H-2b haplotype increased hormone-induced ovulation rate 92% on the A/J (A) genetic background. However, H-2 haplotype did not affect hormone-induced ovulation rate on the C57BL/10J (C57) genetic background. The H-2b-linked gene(s) increased hormone-induced ovulation rate on the A/J genetic background largely by (1) enhancing the maturation of follicles in response to pregnant mare's serum gonadotrophin (PMSG) and (2) altering the stages of follicular development which can be induced to ovulate in response to human chorionic gonadotrophin (hCG). The observed effects of H-2 on hormone-induced ovulation rate were not explained by differences in the timing of puberty, the number of follicles present in untreated females, or the incidence of follicular atresia. The effect of genetic background on hormone-induced ovulation rate was much greater than was the effect of the H-2 region. We found that hormone-induced ovulation rate was five- to six-fold higher on the C57 genetic background than on the A genetic background. The C57 genetic background increased hormone-induced ovulation rate by (1) enhancing the induction of follicular maturation in response to gonadotropins and (2) by reducing the incidence of follicular atresia.

THE EFFECT OF INITIAL AGE ON THE RESPONSE OF THE RAT TO TREATMENT WITH GONADOTROPHINS

1973 ◽  
Vol 72 (2) ◽  
pp. 209-217
Author(s):  
S. F. Lunn ◽  
J. A. Loraine
Keyword(s):  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Ovulation Rate ◽  
Maximum Response ◽  
Induced Ovulation

ABSTRACT In the rat, the age at which the maximum response to gonadotrophin treatment will occur is dependent on both the parameter being examined and the hormone, or combination of hormones used. Thus, the ovulation rate following treatment with pregnant mares' serum gonadotrophin (PMSG) alone, or in combination with human chorionic gonadotrophin (HCG), is maximal at an earlier age than that observed for HCG alone. From the data presented, it would seem that, for the conditions employed, the optimal age of animals for studies on gonadotrophin-induced ovulation would be approximately thirty days.

THE PRECISION OF THE OVARIAN ASCORBIC ACID DEPLETION TEST FOR LUTEINIZING HORMONE

1963 ◽  
Vol 43 (1) ◽  
pp. 155-160
Author(s):  
Jørgen Falck Larsen ◽  
Christian Hamburger
Keyword(s):  
Ascorbic Acid ◽  
Luteinizing Hormone ◽  
Clinical Analysis ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin

ABSTRACT Various modifications of the Parlow test for luteinizing hormone (ovarian ascorbic acid depletion in rats) were tried. Human chorionic gonadotrophin was used instead of hypophyseal luteinizing hormone. The precision of the method was found to be so low, however, that the test could not be used for routine clinical analysis. The low precision found in this and other laboratories is thought to be due to the strains of rats used.

STUDIES ON THE AROMATISATION OF NEUTRAL STEROIDS IN PREGNANT WOMEN

1964 ◽  
Vol 45 (4) ◽  
pp. 535-559 ◽  
Author(s):  
E. Bolté ◽  
S. Mancuso ◽  
G. Eriksson ◽  
N. Wiqvist ◽  
E. Diczfalusy
Keyword(s):  
Pregnant Women ◽  
Comparative Studies ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Radioactive Material ◽  
Placental Barrier ◽  
Therapeutic Abortion ◽  
Limited Ability ◽  
Better Than

ABSTRACT In 15 cases of therapeutic abortion by laparotomy the placenta was disconnected from the foetus and perfused in situ with tracer amounts of radioactive dehydroepiandrosterone (DHA), dehydroepiandrosterone sulphate (DHAS), androst-4-ene-3,17-dione (A), testosterone (T) and 17β-oestradiol (OE2). Analysis of the placentas, perfusates and urine samples revealed an extensive aromatisation of DHA, A and T; more than 70% of the radioactive material recovered was phenolic, and at least 80 % of this phenolic material was identified as oestrone (OE1), 17β-oestradiol (OE2) and oestriol (OE3), the latter being detected only in the urine. Comparative studies indicated that A and T were aromatised somewhat better than DHA and that all three unconjugated steroids were aromatised to a much greater extent than DHAS. Radioactive OE1 and OE2 were isolated and identified in the placentas and perfusates, but no OE3, epimeric oestriols, or ring D ketols could be detected in these sources, not even when human chorionic gonadotrophin (HCG) was added to the blood prior to perfusion. Lack of placental 16-hydroxylation was also apparent when OE2 was perfused. Regardless of the precursor perfused, there was three times more OE2 than OE1 in the placenta and three times more OE1 than OE2 in the perfusate. This was also the case following perfusion with OE2. The results are interpreted as suggesting the existence in the pregnant human of a placental »barrier« limiting the passage of circulating androgen. The barrier consists of a) limited ability to transfer directly DHAS and b) an enzymic mechanism resulting in the rapid and extensive aromatisation of the important androgens DHA, A and T.

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