Effects of active and passive gonadotrophin-releasing hormone immunization on recognition and establishment of pregnancy in pigs

2000 ◽  
Vol 12 (6) ◽  
pp. 277 ◽  
Author(s):  
A. Tast ◽  
R. J. Love ◽  
I. J. Clarke ◽  
G. Evans
Keyword(s):  
Passive Immunization ◽  
Active Immunization ◽  
Corpora Lutea ◽  
Plasma Samples ◽  
Releasing Hormone ◽  
Booster Immunization ◽  
Commercial Vaccine ◽  
Pregnancy Testing ◽  
Complete Failure ◽  
Gonadotrophin Releasing Hormone

This study investigated the effects of a reduction in gonadotrophins, by means of differently timed active and passive gonadotrophin-releasing hormone (GnRH) immunization at various stages, on the maintenance of early pregnancy in pigs. In the first experiment crossbred sows (n = 11) were immunized against GnRH using a commercial vaccine on the day of farrowing, mated at the first oestrus, and a booster immunization was administered 10 days (n = 7) or 20 days (n = 4) after mating. Plasma samples were collected every second day and assayed for GnRH antibodies and progesterone. Pregnancy testing was carried out by real time ultrasound. None of the sows receiving the booster immunization 10 days after mating were pregnant on Day 18 after mating. All sows receiving the booster on Day 20 after mating aborted, with a mean vaccination-to-abortion interval of 10.0 1.5 days. In the second experiment, crossbred gilts (n = 6) were passively immunized by infusing (i.v.) GnRH immune pig serum on Day 12 after mating. Luteinizing hormone profiles were determined on the day before immunization and one day afterwards. Daily plasma samples were assayed for GnRH antibodies and progesterone. None of the gilts were pregnant 18 days after mating, compared with 5 of 6 non-immunized controls. Booster immunization 10 days after mating resulted in failure of embryonic development and establishment of pregnancy before the corpora lutea (CL) regressed, according to progesterone profiles, whereas immunization 20 days after mating resulted in regression of CL followed by abortion. Passive immunization 12 days after mating had a similar effect to the active immunization 10 days after mating. These results demonstrate two different outcomes of active GnRH immunization depending on the timing of immunization, and indicate that loss of pregnancy between Days 12 and 18 may occur due a reduction in progesterone rather than complete failure of the CL, as occurs at later stages. The findings may provide an explanation for the reduced fertility of pigs in the summer–autumn period.

83 Response to follicle-stimulating hormone superstimulation in heifers with ovarian activity suppressed by active immunization against gonadotrophin-releasing hormone

2021 ◽  
Vol 33 (2) ◽  
pp. 149
Author(s):  
N. E. S. Pereira ◽  
L. P. Martins ◽  
R. M. Moura ◽  
L. R. O. Dias ◽  
M. A. S. Peixer ◽  
...  
Keyword(s):  
Active Immunization ◽  
Repeated Measure ◽  
Ovarian Activity ◽  
Corpora Lutea ◽  
Follicle Growth ◽  
Releasing Hormone ◽  
Significant Difference ◽  
Follicle Size ◽  
Gonadotrophin Releasing Hormone ◽  
Group B

In the present study, we evaluated the ovarian response to exogenous FSH stimulation in the absence of endogenous LH, using as experimental model heifers immunized against GnRH. Pubertal, cycling Nelore (Bos indicus) heifers were allocated into three experimental groups: (1) non-immunized, FSH stimulated (B−FSH+, n=5), (2) immunized, FSH stimulated (B+FSH+, n=5), and (3) immunized, nonstimulated (B+FSH−, n=5). Active immunization was obtained by 3 subcutaneous injections of 1.0mL anti-gonadotrophin-releasing hormone vaccine (Bopriva, Zoetis), given at 20-day intervals. Effective immunization was characterised by the absence of growing follicles >4mm or corpora lutea (CL) on the ovaries. Follicular wave emergence was synchronized in groups B+FSH+ and B+FSH− by follicle ablation, and in group B−FSH+ by using of a protocol consisting of an injection of 2mg of oestradiol benzoate and 0.5mg of sodium cloprostenol, and insertion of an intravaginal progesterone (P4) device (1g). Four days later (Day 0), groups B−FSH+ and B+FSH+ received 100mg of NIH-FSH-P1 (Folltropin-V, Vetoquinol), injected twice-a-day in 8 decreasing doses, and group B+FSH− received saline. Transvaginal ultrasonography (7.5MHz) was performed daily from Days 0 to 4 and the number and size of follicles were recorded. P4 devices of group B-FSH+ were removed at Day 3. All heifers underwent ovum pickup (OPU) at Day 4, and the cumulus–oocyte complexes (COC) recovered were graded for quality. Viable COC were used for invitro embryo production. The heifers were re-evaluated at Day 11 (7 days after OPU). The GLIMMIX procedure from SAS (SAS Institute Inc.) with repeated-measure statement was used to analyse the effects of group, day, and interactions; and the Chi-squared method was used to analyse binomial data. The results are shown as mean±s.e.m. A progressive increase in average follicle size was observed in groups B−FSH+ and B+FSH+ (P<0.0001), whereas no follicle growth was observed in group B+FSH− (P>0.05). Follicle growth rate was similar between groups B−FSH+ and B+FSH+, and both were greater than group B+FSH− (1.2±0.2 and 1.1±0.1 vs. 0.0±0.1 mm/d; P<0.0001). However, the smaller follicle size in group B+FSH+ at Day 0 resulted in smaller follicle size at Day 4, compared with group B−FSH+ (2.4±0.1 vs. 3.6±0.2 and 6.9±0.7 vs. 8.2±0.6mm, respectively; P<0.05). There was no (P>0.05) difference in the number of COC recovered among groups. The group B+FSH+ yielded fewer (P<0.01) COC of grades I and II and more (P<0.01) degenerated oocytes than groups B−FSH+ and B+FSH− (41.2% vs. 80.0% and 68.0%, and 34.0% vs. 19.8 and 7.0%, respectively). Nevertheless, blastocyst rates were similar (P>0.05) for B−FSH+, B+FSH+, and B+FSH− (57.1%, 45.9% and 44.2%, respectively). Residual follicles or luteal tissue were observed after OPU only in group B−FSH+, resulting in a significant difference in the size of ovaries between Days 0 and 11, compared with that of groups B+FSH+ and B+FSH− (3.7±1.4 vs. 0.2±0.2 and −0.2±0.2cm2, respectively; P<0.05). In summary, exogenous FSH supported follicle growth but did not improve oocyte quality in heifers immunized against GnRH. This research was funded by CAPES.

Active Immunization against Gonadotrophin-releasing Hormone in Chinese Male Pigs

2001 ◽  
Vol 36 (2) ◽  
pp. 101-105 ◽  
Author(s):  
XY Zeng ◽  
JA Turkstra ◽  
DFM van de Wiel ◽  
DZ Guo ◽  
XY Liu ◽  
...  
Keyword(s):  
Active Immunization ◽  
Releasing Hormone ◽  
Gonadotrophin Releasing Hormone ◽  
Chinese Male

Passive immunization against LHRH in cattle using a monoclonal antibody

1991 ◽  
Vol 1991 ◽  
pp. 16-16
Author(s):  
A F Carson ◽  
W J McCaughey ◽  
R W J Steen
Keyword(s):  
Monoclonal Antibody ◽  
Half Life ◽  
Aggressive Behaviour ◽  
Luteinising Hormone ◽  
Passive Immunization ◽  
Active Immunization ◽  
Releasing Hormone ◽  
Binding Characteristics ◽  
Testosterone Production ◽  
Immunological Castration

In comparison to steers, bulls have produced 10% higher liveweight gain, 14% higher carcase gain and 20% more lean in the carcase. Immunological castration, which is reversible may reduce aggressive behaviour and maintain the performance advantages of bulls. Active immunization against luteinising hormone releasing hormone (LHRH) reduces testosterone production and therefore aggression in bulls. However, a controlled, predictable response to vaccination has not been achieved. Consistent immunization may be possible using a monoclonal antibody against LHRH. An anti-LHRH monoclonal antibody was developed and studies were carried out to determine the binding characteristics of the antibody and the half-life when administered to 6 post-pubertal bulls. The ability of the antibody to neutralize the bioactivity of LHRH was investigated in bulls and mice.

160 Increasing gonadotrophin-releasing hormone dose at initiation of a 5-day CO-Synch protocol increases ovulatory response but not fertility in yearling beef heifers

2020 ◽  
Vol 32 (2) ◽  
pp. 206
Author(s):  
E. Rojas Canadas ◽  
S. E. Battista ◽  
J. Kieffer ◽  
S. Wellert ◽  
A. Garcia Guerra
Keyword(s):  
Dose Group ◽  
Fixed Time ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Double Dose ◽  
Device Removal ◽  
Beef Heifers ◽  
Releasing Hormone ◽  
Gonadotrophin Releasing Hormone ◽  
To Receive

Heifers typically have a reduced ovulation rate following gonadotrophin-releasing hormone (GnRH) application at initiation of a CO-Synch + controlled internal drug release (CIDR) protocol. Thus, the objective of the present study was to determine whether increasing the dose of GnRH at initiation of a 5-day CO-Synch protocol in beef heifers would improve ovulation rate and therefore increase pregnancies per AI (P/AI). Angus yearling heifers (n=299) at five locations in Ohio (United States) were randomised to receive either 100µg (single; n=149) or 200µg (double; n=150) of gonadorelin acetate (Gonabreed, Parnell) at initiation of a 5-day CO-Synch. On Day −8, heifers received a new intravaginal progesterone-releasing device (1.38g of progesterone; CIDR, Zoetis) and either a single or double dose of GnRH as described above. Five days later (Day −3), devices were removed, 1000µg of cloprostenol sodium (Estroplan, Parnell) was administered, and an oestrous detection patch was applied (Estrotect, Rockway Inc.). Sixty hours after device removal, AI was performed concurrently with the administration of 100µg of GnRH. Pregnancy was determined using ultrasonography 35 days after AI. Ovaries from a subset of animals (n=178) were examined on Days −8 and −3 using ultrasonography to determine the presence of corpora lutea (CL) and the size of the largest follicle. Data were analysed using the GLIMMIX procedure of SAS ver. 9.4 (SAS Institute Inc.). Oestrous expression was similar (P=0.50) between heifers treated with a single (49.0%) or double (52.7%) dose of GnRH. Overall, P/AI was similar (P=0.35) between heifers receiving a single (43.6%; 65/149) or double (38.7%; 58/150) dose of GnRH at initiation of the protocol. However, increasing the dose of GnRH resulted in a greater (P=0.04) ovulation rate in heifers in the double-dose group (40.9%; 36/88) compared with those in the single-dose group (26.1%; 23/88). In addition, heifers with a CL at the time of treatment had reduced ovulatory response to GnRH treatment (16.0%) compared with heifers without a CL (53.7%; P=0.001); however, there was no treatment×CL presence interaction (P=0.69). Heifers that did not ovulate to the initial GnRH treatment had a greater (P=0.0008) diameter of the largest follicle on Day −3 compared with heifers that did ovulate (11.4±0.2 vs. 10.0±0.3). Furthermore, heifers that did ovulate after the initial GnRH had greater (P=0.04) P/AI (52.5%) than heifers that did not ovulate (40.2%), and heifers with a CL on Day −8 tended (P=0.07) to have greater P/AI (47.9%) than heifers without a CL (40.2%). In addition, heifers with a CL present on Day −3 had greater (P=0.04) P/AI (48.2%) than heifers without a CL (31.7%). In summary, increasing the dose of GnRH at initiation of a 5-day CO-Synch did not affect fertility to fixed-time AI but enhanced ovulation rate in beef heifers. Furthermore, heifers that did ovulate at initiation of the protocol or that had a CL at device insertion or removal had greater fertility to fixed-time AI. Thus, alternative strategies that maximise ovulation at initiation of the synchronisation protocol are needed.

EFFECT OF ACTIVE IMMUNIZATION TO LUTEINIZING HORMONE RELEASING HORMONE ON SERUM AND PITUITARY GONADOTROPHINS, TESTES AND ACCESSORY SEX ORGANS IN THE MALE RAT

1974 ◽  
Vol 63 (2) ◽  
pp. 399-NP ◽  
Author(s):  
H. M. FRASER ◽  
A. GUNN ◽  
S. L. JEFFCOATE ◽  
DIANE T. HOLLAND
Keyword(s):  
Luteinizing Hormone ◽  
Active Immunization ◽  
Male Rats ◽  
Male Rat ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Accessory Sex Organs ◽  
Gonadotrophin Releasing Hormone ◽  
Low Levels ◽  
Lh Rh

SUMMARY Autoimmunity to luteinizing hormone releasing hormone (LH-RH) in adult male rats, induced by immunization with LH-RH conjugated to bovine serum albumin, resulted in atrophy of the testes and secondary sex organs and aspermatogenesis. Both immunoreactive luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in serum and the pituitary were reduced to low levels compared with those of control animals. It is suggested that antibodies to LH-RH can inhibit the action of endogenous hormone and that LH-RH is, in fact, the gonadotrophin-releasing hormone in the rat, required for the release of both LH and FSH.

FSH causes a time-dependent stimulation of preovulatory follicle growth in the absence of pulsatile LH secretion in ewes chronically treated with gonadotrophin-releasing hormone agonist

1990 ◽  
Vol 126 (2) ◽  
pp. 297-307 ◽  
Author(s):  
H. M. Picton ◽  
C. G. Tsonis ◽  
A. S. McNeilly
Keyword(s):  
Plasma Concentration ◽  
Gnrh Agonist ◽  
Corpora Lutea ◽  
Preovulatory Follicle ◽  
Follicle Growth ◽  
Releasing Hormone ◽  
Gonadotrophin Releasing Hormone ◽  
The Mean ◽  
Stimulation Of

ABSTRACT The study investigated the relationship between the plasma concentration of FSH and the stimulation of preovulatory follicle growth in vivo in ewes chronically treated with the gonadotrophin-releasing hormone (GnRH) agonist buserelin (HOE 766). Welsh Mountain ewes with regular oestrous cycles were treated for 6 weeks with two discs implants placed s.c., each containing 5 mg of the agonist in a matrix of polyhydroxybutyric acid. Treatment with the agonist for 35 days produced a sustained suppression of the plasma concentration of FSH, stopped the pulsatile release of LH and prevented follicular development beyond 2·5 mm diameter. There was no difference between the total number of follicles > 1·0 mm diameter present in the ovaries of GnRH agonist-treated ewes and day 8 luteal phase control ewes. During the sixth week of agonist treatment ewes were infused with ovine FSH (6 μg NIADDK-oFSH16/h) in the presence of only basal concentrations of LH. After 24, 48, 72 or 120 h of FSH infusion, the mean number of follicles > 1 ·0 mm diameter per ewe was not significantly different between treated and control animals. Infusion of FSH caused a timedependent increase in (1) the number of follicles per ovary >2·5 mm, (2) the mean diameter of these follicles and (3) the proportion of the large follicles which could be classified as oestrogenic (> 3·7 nmol oestradiol/follicle per h in vitro). Injection of human chorionic gonadotrophin (750IU i.m.) after 120 h of FSH infusion caused the majority of these large follicles to ovulate and form apparently normal corpora lutea. These results indicate that, in the absence of pulsatile LH, FSH stimulates the growth of normal large oestrogenic follicles which, when stimulated, ovulate to produce viable corpora lutea. Journal of Endocrinology (1990) 126, 297–307

Rat granulosa cells express the gonadotrophin-releasing hormone gene: evidence from in-situ hybridization histochemistry

1992 ◽  
Vol 9 (3) ◽  
pp. 189-195 ◽  
Author(s):  
R. N. Clayton ◽  
L. Eccleston ◽  
F. Gossard ◽  
J.-C. Thalbard ◽  
G. Morel
Keyword(s):  
Follicular Development ◽  
Protein Product ◽  
Corpora Lutea ◽  
Cell Compartment ◽  
Hybridization Histochemistry ◽  
Releasing Hormone ◽  
Alternative Protein ◽  
Thecal Cells ◽  
Gonadotrophin Releasing Hormone

ABSTRACT There is still debate as to whether natural sequence gonadotrophin-releasing hormone (GnRH) is produced in the mammalian gonads and concerning its potential role as a paracrine modulator of gonadal function. To address this question, we have used insitu hybridization histochemistry with an oligonucleotide probe complementary to the GnRH decapeptide coding sequence, to determine the cellular site(s) of expression of the GnRH gene in rodent ovaries. GnRH mRNA was detected in granulosa and thecal cells from ovarian follicles at all stages of development (primary→Graafian), with no significant change in grain density during follicular development. The granulosa cell compartment always contained more mRNA than the thecal cell compartment. Corpora lutea expressed the GnRH gene to the same extent as thecal cells. These results indicate that preproGnRH mRNA is detectable under physiological conditions in the mammalian ovary, though whether this produces authentic GnRH decapeptide or an alternative protein product is not known. The physiological significance of these findings remains to be determined.

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