scholarly journals Urinary Oestrogen Excretion in the Goat During the Oestrous Cycle and after Administration of Pregnant Mare Serum Gonadotrophin (PMSG)

1972 ◽  
Vol 13 (2) ◽  
pp. 272-274
Author(s):  
Torleiu Lunaas ◽  
Olav Lyngset
Keyword(s):  
Oestrous Cycle ◽  
Pregnant Mare Serum Gonadotrophin

The effect of the laparoscopic insemination technique on the oestrous cycle of the ewe

1991 ◽  
Vol 62 (2) ◽  
pp. 60-61
Author(s):  
T. L. Taljaard ◽  
S. J. Terblanche ◽  
H. J. Bertschinger ◽  
L. J. Van Vuuren
Keyword(s):  
Cycle Length ◽  
Intrauterine Insemination ◽  
Uterine Horn ◽  
Oestrous Cycle ◽  
Control Group ◽  
Control Groups ◽  
The Mean ◽  
And Control ◽  
Pregnant Mare Serum Gonadotrophin ◽  
Teaser Rams

This investigation was designed to determine whether or not the technique of intrauterine insemination affects the length of the subsequent oestrous cycle. Dorper ewes (n=31) were divided into treatment and control groups. All the ewes were synchronised using 40 mg fluorogestone acetate intravaginal sponges for 14 d and 300 IU pregnant mare serum gonadotrophin on the day of sponge removal. A standard semen diluent was deposited laparoscopically in each uterine horn of ewes in the treatment, group. Teaser rams were used to detect oestrus. Progesterone profiles were used to confirm oestrus. The mean oestrous cycle length of 17,83 ± 0,69 d for the group in which the diluent was deposited by laparoscopy did not differ significantly (P0,l) from the 18,36±2,11 d of the control group. The technique of laparoscopic insemination did not influence the length of subsequent oestrous cycles.

Effect of type of intravaginal progestagen on the outcome of fixed-time artificial insemination

1981 ◽  
Vol 96 (1) ◽  
pp. 243-245 ◽  
Author(s):  
P. A. Smith ◽  
M. P. Boland ◽  
I. Gordon
Keyword(s):  
Artificial Insemination ◽  
Present Experiment ◽  
Fixed Time ◽  
Field Trials ◽  
Oestrous Cycle ◽  
Conception Rates ◽  
Natural Service ◽  
Dose Levels ◽  
Pregnant Mare Serum Gonadotrophin

It is now possible to synchronize the cycle of ewes at all times of the year (Gordon, 1975). Conception rates approaching those obtained following natural service have been reported following double (Colas & Brice, 1970; Colas et al. 1973; Barlow, Pryce-Jones & Reed, 1974; Gordon, 1975) or single (Smith, Boland & Gordon, 1978) set-time inseminations. In France, synchronization of ewes' oestrous cycle is based on the use of a Cronolone pessary (Colas, 1975), while field trials conducted in Britain have used the 60 mg Medroxy progesterone acetate (MAP) sponge (Barlow et al. 1974). Robinson et al. (1967) in an evaluation of different progestagen treatments found MAP to be less predictable than Cronolone. The purpose of the present experiment therefore was to evaluate the use of a 30 mg Cronolone or a 60 mg MAP intravaginal treatment when used in conjunction with fixed-time inseminations. In addition, two dose levels of pregnant mare serum gonadotrophin (PMSG) were compared.

EFFECT OF GONADOTROPHINS ON THE PRODUCTION OF STEROIDS BY SHEEP OVARIAN FOLLICLES CULTURED IN VITRO

1973 ◽  
Vol 58 (3) ◽  
pp. 599-611 ◽  
Author(s):  
R. M. MOOR ◽  
MARY F. HAY ◽  
J. E. A. McINTOSH ◽  
B. V. CALDWELL
Keyword(s):  
Ovarian Follicles ◽  
Oestrous Cycle ◽  
Culture Period ◽  
Daily Output ◽  
Progesterone Production ◽  
Progesterone Secretion ◽  
The Mean ◽  
Pregnant Mare Serum Gonadotrophin

SUMMARY The main objective of the study was to determine the rate at which Graafian follicles of sheep that had been treated with exogenous gonadotrophin acquire the ability to secrete oestrogen in vitro. Follicles were explanted from sheep 5 min to 24 h after injection of pregnant mare serum gonadotrophin (PMSG) and kept individually in culture for 7 days. The mean daily output of oestrogen by follicles from PMSG-treated sheep was higher than that secreted by follicles from untreated sheep. However, only a certain proportion of the follicles from each sheep secreted significant amounts of oestrogen in vitro; these follicles were called 'stimulated'. The proportion of stimulated follicles was 5% for control sheep, 20–30% for follicles explanted from sheep 5 min to 12 h after injection with PMSG, and 80% for follicles explanted from sheep that had been injected with PMSG 24 h previously. In the second part of the study, the pattern of oestrogen and progesterone secretion by stimulated follicles of different sizes explanted from PMSG-treated sheep at various stages of the oestrous cycle was determined. Up to the 14th day, oestrogen production in vitro by follicles over 4·5 mm in diameter reached a maximum 2 days after PMSG injection and decreased thereafter; progesterone production rose steadily as the oestrogen levels declined. In contrast, follicles of less than 4·5 mm diameter secreted considerable amounts of oestrogen for the first 5 days in culture, but produced only small quantities of progesterone. In follicles explanted on day 15, oestrogen secretion decreased steadily from the beginning of the culture period and was very low by the 4th day. Most follicles explanted at oestrus secreted only small amounts of oestrogen in vitro but secreted large amounts of progesterone.

Effect of dose of Gronolone in intravaginal sponges on lambing outcome to fixed-time artificial insemination

1981 ◽  
Vol 96 (1) ◽  
pp. 253-254 ◽  
Author(s):  
P. A. Smith ◽  
M. P. Boland ◽  
I. Gordon
Keyword(s):  
Artificial Insemination ◽  
Ovarian Stimulation ◽  
Present Experiment ◽  
Intramuscular Injection ◽  
Relative Effectiveness ◽  
Fixed Time ◽  
Oestrous Cycle ◽  
High Concentration ◽  
High Degree ◽  
Pregnant Mare Serum Gonadotrophin

Research has shown that it is now possible to control the oestrous cycle of ewes with a high degree of precision (Robinson et al. 1967; Gordon, 1975; Boland, Kelleher & Gordon, 1978). There is general agreement that a high concentration of progestagen, followed by rapid withdrawal and adequate ovarian stimulation is necessary for acceptable fertility (Robinson et al. 1967; Gordon, 1975; Colas, 1975). Application of artificial insemination in France has involved the use of a 40–45 mg Cronolone sponge (Cognie, Mariana & Thimonier, 1970; Colas et al. 1973) while controlled breeding in sheep in Ireland has been used in conjunction with a 30 mg Cronolone pessary (Gordon, 1975; Smith, Boland & Gordon, 1978, 1981). The present experiment was designed to compare the relative effectiveness of two doses of Cronolone (30 or 45 mg) when administered in conjunction with two quantities(375 or 750 i.u.) of pregnant mare serum gonadotrophin (PMSG), given by intramuscular injection.

PROGESTERONE CONCENTRATION IN THE PERIPHERAL PLASMA OF SHEEP DURING THE OESTROUS CYCLE

1969 ◽  
Vol 45 (3) ◽  
pp. 459-469 ◽  
Author(s):  
G. D. THORBURN ◽  
J. M. BASSETT ◽  
I. D. SMITH
Keyword(s):  
Thin Layer ◽  
Luteal Phase ◽  
Jugular Vein ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
Layer Chromatography ◽  
Pregnant Mare Serum Gonadotrophin

SUMMARY Using a protein-binding technique, progesterone concentrations in peripheral plasma (jugular vein) were measured throughout the oestrous cycle of 24 ewes. Examination of the specificity of the method by thin-layer chromatography indicated that interference from other steroids was not significant in sheep plasma. During the first 4 days of the cycle (days 0–3), plasma progesterone concentrations were below 0·4 ng./ml., increasing to a mean level of 1·5–2·5 ng./ml. between days 4 and 9, and remaining at this level for approximately 5 days, before declining rapidly on days 14 and 15 to reach a low level on the day before oestrus. The progesterone concentration on the day of oestrus was extremely low (0·1 ng./ml.), and was of the same order as that found in the plasma of wethers and anoestrous or ovariectomized ewes. Three ewes, superovulated with pregnant mare serum gonadotrophin, showed marked elevation of peripheral progesterone concentration during the luteal phase of the cycle, the concentration being proportional to the number of corpora lutea formed.

EFFECT ON OVULATION OF 20α-HYDROXY-4-PREGNEN-3-ONE AND ITS 5α-REDUCED METABOLITES IN IMMATURE RATS TREATED WITH PREGNANT MARE SERUM GONADOTROPHIN

1981 ◽  
Vol 88 (2) ◽  
pp. 289-292 ◽  
Author(s):  
PAMELA A. GILLES ◽  
H. J. KARAVOLAS
Keyword(s):  
Oestrous Cycle ◽  
Female Rats ◽  
Immature Female ◽  
Immature Rats ◽  
Pregnant Mare Serum Gonadotrophin

The ability of 20α-hydroxy-4-pregnen-3-one (20α-dihydroprogesterone, 20α-DHP) and its 5α-reduced metabolites, 20α-hydroxy-5α-pregnan-3-one and 5α-pregnane-3α,20α-diol, to facilitate ovulation was examined in immature female rats which had been treated on day 22 of age with a non-ovulatory dose (12 i.u.) of pregnant mare serum gonadotrophin. An increased incidence of ovulation occurred in rats treated on the morning of day 24 with 20α-DHP. However, a dose of 20α-DHP three to four times that of progesterone was required to induce ovulation in all animals. In contrast, neither 20α-hydroxy-5α-pregnan-3-one (at doses ranging from 0·5 to 5·0 mg) nor 5α-pregnane-3α,20α-diol (tested at 3·0 or 4·0 mg) facilitated ovulation. Therefore both 20α-DHP and progesterone, the two major progestins of the rat oestrous cycle, have the ability to facilitate ovulation. It is concluded that the ability of 20α-DHP to facilitate ovulation does not appear to be by way of conversion to its 5α-reduced metabolites.

The effect of pregnant mare serum gonadotrophin and human chorionic gonadotrophin on ovulation and on fertility in the ewe

1970 ◽  
Vol 21 (5) ◽  
pp. 807 ◽  
Author(s):  
ID Killeen ◽  
NW Moore
Keyword(s):  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Oestrous Cycle ◽  
Multiple Births ◽  
Multiple Ovulation ◽  
Subsequent Fertility ◽  
Direct Reflection ◽  
Pregnant Mare Serum Gonadotrophin

An experiment involving 300 cyclic Merino ewes and designed to study the effects of pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (HCG) on ovulation and subsequent fertility is described. PMSG (750 i.u.) was given on the 12th day of the oestrous cycle and HCG (400 and 800 i.u.) was injected intravenously within 3 hr of the onset of oestrus. PMSG induced multiple ovulation and hastened the time of ovulation in relation to the onset of oestrus by 2-3 hr, but did not enhance the precision of the time of ovulation. HCG had no effect upon the time of ovulation but did increase the proportion of follicles which ruptured. Neither PMSG nor HCG, alone or in combination, adversely affected fertility. In fact, HCG increased the proportion of ewes which lambed. Both PMSG and HCG increased the incidence of multiple births. The effect of PMSG on the incidence of multiple births was a direct reflection of its ability to induce multiple ovulation. HCG given alone, or after PMSG increased the incidence of multiple births but its effect was less marked than that of PMSG, and unlike that of PMSG the effect of HCG did not appear to be solely due to an increase in the number of ovulations.

THE EFFECTS OF RAT PITUITARY AND HYPOTHALAMIC TISSUE TRANSPLANTED IN SUPEROVULATED IMMATURE RATS

1968 ◽  
Vol 40 (3) ◽  
pp. 363-369
Author(s):  
T. F. HOPKINS ◽  
H. ORY ◽  
EMILY DESPRES ◽  
SAYID. M. HUSAIN ◽  
G. PINCUS
Keyword(s):  
Median Eminence ◽  
Liver Tissue ◽  
Oestrous Cycle ◽  
Kidney Capsule ◽  
Close Proximity ◽  
Rat Pituitary ◽  
Immature Rats ◽  
Hypothalamic Tissue ◽  
Series Of Experiments ◽  
Pregnant Mare Serum Gonadotrophin

SUMMARY The ovulatory response to pregnant mare serum gonadotrophin (PMS) was studied in immature rats bearing adenohypophysial (AP) and hypothalamic median eminence (ME) tissues grafted beneath the kidney capsule. A small piece of liver tissue only was grafted in control rats. PMS (30 i.u.) was administered subcutaneously to all rats on the fourth day after the grafts had been placed. The ovulatory response was depressed in all rats bearing AP tissue alone. Median eminence tissue transplanted from immature rats or from mature rats in various phases of the vaginal oestrous cycle had no effects on ovulation when transplanted alone. When present as a joint graft with AP tissue, pro-oestrous ME augmented the depressing effects on ovulation. In one series of experiments, the average number of ova in 29 liver tissue controls was 34·2 ± 9·6 with all the rats ovulating. The average number of ova in 24 rats bearing AP tissue was 19·7 ± 5·2 with 46% ovulating. In eight rats bearing AP plus early pro-oestrous ME, the average number of ova was 0·25 ± 0·25 with 12·5% ovulating. Augmentation of AP depressing effects was not apparent in rats bearing AP plus dioestrous or oestrous ME tissue. These results show that the ovulatory response to PMS is depressed by AP tissue grafted beneath the kidney capsule and suggests that pro-oestrous ME tissue grafted in close proximity to the AP tissue in some way augments the depressing effects.

Some morphological and hormonal aspects of ovulation and superovulation in the rat

1994 ◽  
Vol 141 (1) ◽  
pp. 91-100 ◽  
Author(s):  
M Szołtys ◽  
J Galas ◽  
A Jabłonka ◽  
Z Tabarowski
Keyword(s):  
Wistar Rats ◽  
Histological Analysis ◽  
General Pattern ◽  
Mature Female ◽  
Oestrous Cycle ◽  
Preovulatory Follicles ◽  
Female Wistar Rats ◽  
Theca Interna ◽  
Histological Procedure ◽  
Pregnant Mare Serum Gonadotrophin

Abstract In the first experiment, mature female Wistar rats, displaying a regular 4-day oestrous cycle, were killed in succession every 2 or 3 h on the day of pro-oestrus and oestrus until the time of ovulation. In the second experiment, immature female Wistar rats (aged 24 days) were injected s.c. with 30 IU pregnant mare serum gonadotrophin (PMSG) and 56 h later with 20 IU human chorionic gonadotrophin (hCG). They were killed in groups at 0, 24, 48, 56 and 57 h, and then every 2 h until 72 h. Excised ovaries were homogenized and analysed for steroid content or they were submitted to a routine histological procedure. The cyclic and PMSG/hCG-treated rats exhibited some similarities and differences in the general pattern of steroid content. Either a presumptive endogenous LH surge or administration of hCG resulted in an increase in the ovarian androgen concentration which preceded a rise in progesterone; the progesterone peak, in turn, was accompanied by a fall in the amount of androgens and oestradiol. However, in comparison with cyclic rats, superovulated animals displayed a significantly higher ovarian androgen level for a prolonged period; ovarian oestradiol concentration was also raised while the progesterone content was much lower. Histological analysis revealed large differences between the ovaries of superovulated and cyclic rats, especially with regard to the maturing follicles. The majority of PMSG/hCG-derived follicles showed hypertrophied theca interna and degenerated or luteinized granulosa. A large number of preovulatory follicles did not ovulate. These results clearly indicate that PMSG/hCGinduced follicles are not equal to the follicles developing during a normal oestrous cycle. This should be taken into consideration when using superovulated animals in experiments. Journal of Endocrinology (1994) 141, 91–100

NEW DATA CONCERNING THE ROLE PLAYED BY PROGESTERONE IN THE CONTROL OF FOLLICULAR GROWTH IN THE RAT

1974 ◽  
Vol 75 (3) ◽  
pp. 569-578 ◽  
Author(s):  
G. Buffler ◽  
S. Roser
Keyword(s):  
Wistar Rats ◽  
Venous Blood ◽  
Oestrous Cycle ◽  
Female Rats ◽  
Cycle Duration ◽  
Follicular Growth ◽  
The Third ◽  
Female Wistar Rats

ABSTRACT The mechanisms involved in the prolongation of the oestrous cycle following LH administration were studied in 4-day cyclic female Wistar rats. In females injected with LH on the morning of dioestrus I there was an increase in ovarian venous blood progesterone as compared with non-injected animals. In both LH-treated females, and those injected with progesterone on the morning of dioestrus I, a slowing up in follicular growth was observed from the afternoon of dioestrus I. The size of follicles greater than 400 urn present in LH or progesterone injected animals on the third day of cycle was similar to the size reached by the same range of follicles in non-injected animals on the second day of the cycle. Hence, the increase in endogenous ovarian progesterone elicited by LH was considered as the cause of the slowing up of follicular growth and therefore of the lengthening of the oestrous cycle duration in female rats injected with LH at the beginning of 4-day cycle.

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