Higher Luteinizing Hormone Concentrations Research Articles

Post-trigger luteinizing hormone concentration to positively predict oocyte yield in the antagonist protocol and its association with genetic variants of LHCGR

BackgroundThe concentration of human chorionic gonadotropin (hCG)/ luteinizing hormone (LH) after triggering is generally accepted as a predictor of the normal ovarian response to the trigger, but few studies have explored the distribution model of concentration and its impact on oocyte yield. Genetic variations in LHCGR, known as a receptor for hCG and LH, also play a role in oocyte maturation and retrieval. The objective of the study was to investigate the impact of concentrations of hCG/LH after triggering on oocyte yield and its association with genetic variants of LHCGR.MethodsA retrospective cohort study including 372 antagonist IVF cycles, in which 205 received the recombinant hCG trigger and 167 received the gonadotropin-releasing hormone agonist (GnRH-a) trigger, was conducted. The post-trigger concentrations of hCG/LH and the LHCGR N312S (rs2293275) genotype were evaluated in patients to analyse the impact of these factors on oocyte yield.ResultsThe oocyte retrieval rate (ORR) increased significantly among the low-, medium- and high-hCG-concentration groups (0.91 ± 0.25, 0.99 ± 0.23 and 1.08 ± 0.19, P < 0.001) and among the low-, medium- and high-LH-concentration groups (0.80 ± 0.29, 0.95 ± 0.21 and 1.07 ± 0.19, P < 0.001). The Pearson correlation coefficient between the post-trigger hCG concentration and ORR was 0.242 (P < 0.001), and that between the LH concentration and ORR was 0.454 (P < 0.001). After adjustment for confounding factors, high post-trigger LH concentrations remained associated with the significantly higher ORRs (adjusted R2 = 0.541, P < 0.001). Patients with the AG genotype of LHCGR N312S were more likely to have low post-trigger LH concentrations (46.10 IU/L versus 60.91 IU/L, P < 0.001) and a significantly lower ORR (0.85 versus 0.96, P = 0.042) than patients with the GG genotype after the GnRH-a trigger.ConclusionsThe post-trigger LH concentration can positively predict oocyte yield in antagonist IVF cycles, and patients with the AG genotype of LHCGR rs2293275 could have a suboptimal oocyte yield using the GnRH-a trigger.

Circulating sex hormone levels in relation to male sperm quality

BackgroundAlthough sex hormones play critical roles in spermatogenesis and sperm maturation, it remains inconclusive whether circulating sex hormones can serve as non-invasive biomarkers to improve the assessment of sperm quality.MethodsWe systematically evaluated the association of various sex hormones in serum with sperm quality among 338 men in subfertile couples. Concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), total testosterone (TT), total estradiol (E2), and sex hormone-binding globulin (SHBG) were detected by chemiluminescent immunoassay. Free testosterone and estradiol were calculated using a validated algorithm. A generalized liner regression model controlling for lifestyle factors was used to evaluate the associations with sperm count, concentration, motility, and morphology.ResultsAfter adjusting for age, body mass index, current smoking and alcohol drinking, LH, FSH, and TT levels were all inversely associated with sperm motility (all P for trend < 0.05); however, in mutual adjustment analysis, only LH remained an inverse association with sperm motility after adjusting for FSH and TT levels (P for trend = 0.04). Higher concentrations of LH were also associated with lower sperm progressive motility (P for trend = 0.04). Moreover, LH and FSH levels were both inversely associated with normal sperm morphology (P for trend = 0.04 and 0.02, respectively).ConclusionsIncreased levels of LH are associated with poor sperm motility and morphology, suggesting that LH may play a central role in sperm maturation. Future studies are warranted to assess potential clinical utility of LH for risk stratification and tailed prevention of male infertility.

Phytomedical Potentials of &lt;i&gt;Chromolaena Odorata&lt;/i&gt; Against Arsenic-Induced Testicular Toxicity In Wistar Rats

The testicular, sperm and endocrine protective properties of Chromolaena odorata (CA) in arsenic treated rats were investigated using forty male wistar rats (190-200g) grouped into 4 (A to D) of ten rats each. Oral administrations for 2 weeks of 0.2ml corn oil (A), 2.5mg/kg of sodium arsenite (B), 200mg/kg ethanol leaf extract (ELE) of CA (C), 200mg/kg ELE of CA and 2.5mg/kg sodium arsenite given at 1 hour interval (D) were done. Twenty-four hours after final administrations, semen, blood biochemical and hormonal analyses were carried out after sacrifice of the rats. Results revealed that Group C’s mean scrotal circumference, Left and Right testicular weights were highest across groups and significant compared to group B values (p&lt;0.05). Group C had significantly (P&lt;0.05) highest mean value of sperm motility across the groups just as group A was significantly (p&lt;0.05) higher than those of groups B and D. Significantly low Testosterone and high luteinizing hormone concentrations were observed in group B. It was concluded in this study that ethanol leaf extract of Chromolena odorata had a profound scrotal, testicular, sperm and endocrine protective properties in arsenic-treated wistar strain albino rats.&#x0D; Keywords: Chromolaena odorata, Reproductive toxicity, Arsenic, Testicular, Wistar rats

Luteinizing Hormone Levels Relate to the Unfavorable Pathology of Prostate Cancer.

Purpose: This study analyzed the association between sex hormone concentrations and stage/condition in patients with prostate cancer. Materials and methods: The concentrations of sex hormones, including testosterone (total, free, and bioavailable), sex hormone-binding globulin (SHBG), luteinizing hormone (LH), and follicle-stimulating hormone (FSH), were measured in 415 patients diagnosed with prostate cancer. Differences in serum hormone concentrations after receiving androgen deprivation therapy (ADT) and after withdrawal from ADT were evaluated. Pathologic characteristics were assessed in the 225 patients unexposed to ADT with a history of radical prostatectomy. Logistic regression analysis was performed to identify factors predictive of unfavorable pathology (Grade ≥3, ≥T3a, or N1). Results: Of the 415 prostate cancer patients, 130 (31.3%) were assessed before treatment, 171 (41.2%) after surgery, 35 (8.4%) after biochemical recurrence, and 59 (14.2%) during ADT, whereas 20 (4.8%) had castration-resistant prostate cancer. FSH was significantly lower after compared to before prostatectomy (3.229 ± 4.486 vs. 5.941 ± 7.044 mIU/mL, p < 0.001). LH, FSH, and testosterone decreased significantly 3 months after starting ADT, but increased 3 months after ADT withdrawal, whereas SHBG was unchanged. Multivariate analysis showed that high LH (odds ratio [OR]: 1.59, 95% confidence interval [CI]: 1.03–2.47, p = 0.0376) and prostate-specific antigen (PSA) (OR: 1.13, 95% CI: 1.03–1.24, p = 0.0133) concentrations were significantly associated with a high risk of unfavorable pathology. Conclusions: Sex hormones, including LH, FSH, and testosterone, were affected by ADT. The FSH level decreased after radical prostatectomy. High baseline LH concentration in patients unexposed to ADT was associated with an unfavorable pathology.

Luteinizing hormone concentrations in healthy horses and horses with trigeminal-mediated headshaking over an 8-hour period.

BackgroundTrigeminal‐mediated headshaking results from a low threshold for firing of the trigeminal nerve. A seasonal component has been implicated in onset of clinical signs, which occur during the spring and summer months. Geldings are overrepresented in the affected population and hormonal differences as compared to a healthy control population of geldings might contribute to headshaking.Objective/HypothesisTo assess concentrations of luteinizing hormone (LH) over an 8‐hour period in gelded healthy controls and horses affected with headshaking. Our hypothesis was that geldings with seasonal headshaking would have higher concentrations of LH over an 8‐hour period compared to control horses during the summer when affected horses manifested headshaking.AnimalsTwelve geldings (6 controls and 6 affected).MethodsProspective controlled trial. Blood samples were drawn every 15 minutes over an 8‐hour time period during summer from all horses to measure circulating LH concentrations by using a radioimmunoassay for equine LH. All affected horses were actively affected by headshaking at the time of sample collection.ResultsNo statistically significant differences in LH concentrations were found throughout the study period in headshakers as compared to control horses. Time had no significant effect, but a slight decrease in LH concentrations was observed for all horses. The main limitation of the study was the low number of horses.Conclusions and Clinical ImportanceHorses affected with headshaking did not have significant differences in circulating LH during the late summer as compared to control horses.

High luteinizing hormone weakens urinary continence mechanisms in association with prostaglandin E2 elevation in a postmenopausal rat model.

To explore the role of luteinizing hormone (LH) in the urinary continence mechanism, urethral function was investigated using a postmenopausal rat model with high serum LH concentrations and the postmenopausal rat model given a gonadotropin releasing hormone (GnRH) antagonist to lower LH concentrations. Adult female rats were divided into: 1) sham group; 2) ovariectomy group (OVX) with removal of bilateral ovaries; 3) OVX and GnRH-antagonist administered group (OVX + G); and 4) sham and GnRH-antagonist administered group (Sham + G). Urethral function was evaluated by the sneeze-induced urethral continence reflex experiment, and serum LH and prostaglandin E2 (PGE2) concentrations were measured. In the sneeze-induced urethral continence reflex experiment, urethral baseline pressure (UBP) and the amplitude of the urethral response during sneezing (A-URS) were measured. The UBP was significantly decreased in the OVX group than in the other groups. A-URS was significantly lower in the OVX group than in the Sham group, but with no significant difference compared with the OVX + G group. Lowering the serum LH by a GnRH-antagonist improved UBP to the same level as in the Sham group. The serum PGE2 concentration was significantly higher in the OVX group than in the other groups. The results suggested that the increased serum LH concentration in the OVX rat model worsened the continence mechanism. This mechanism is probably associated with an increased PGE2 concentration, because PGE2 caused urethral smooth muscle relaxation. A GnRH-antagonist might improve urinary incontinence by decreasing the serum LH and PGE2 concentrations.

Pubertal Development

Pubertal Development

Different wavelengths of light on GnRH mRNA, LH, steroid hormones and egg lay in the ageing hens (Gallus gallus domesticus).

The aim of this study was to investigate the effects of red spectrum of light (650nm, treated n=12) and normal spectrum of light (450nm control=12) on circulating concentrations of luteinizing hormone (LH), progesterone (P4), estradiol (E2β), GnRH mRNA, pause days and egg production in birds later in the reproductive period from 92-102weeks of age. Twenty-four White Leghorn birds of same age group were divided into two groups of 12 in each as control and treated. Birds in the control group were exposed to normal spectrum of light (450nm of length) and birds in the treated group were exposed to red spectrum of light (650nm, treated n=12). Egg production and inter sequence pauses were recorded daily from both the groups. Plasma LH, E2β and P4 concentrations were estimated in blood samples collected at weekly intervals. At 97th weeks of age, blood samples from treated and control birds were obtained every 3 h for 36 h to study the surges of LH. It was found that plasma GnRH was higher (p &lt; 0. 01) in treated birds with high concentrations of LH, its 3 h LH surges, E2β and P4 in plasma. Higher egg production, less pause days in treated birds may be the result of high GnRH associated with positively correlated responses of high concentrations of LH (with regular interval and duration of LH surges), E2β and P4 concentration required for completion of egg formation and oviposition. In conclusion, red spectrum of light enhanced GnRH mRNA (p &lt; 0. 01), increased (p &lt; 0. 01) steroid hormones and LH surges, for egg formation and oviposition and enabled the birds to lay more eggs even later in the productive period with the available resources under normal husbandry practices.

Osteocalcin and the pituitary-gonadal axis in older men: a population-based study.

Osteocalcin is a well-known marker of bone formation. Recently, mice lacking osteocalcin or its receptor were reported to be subfertile with low testosterone and high luteinizing hormone concentrations. In parallel, in humans, a loss-of-function mutation of the osteocalcin receptor was associated with hypergonadotropic hypogonadism. This suggests that osteocalcin is necessary for normal pituitary-gonadal axis function. Our objective was to determine the association between physiological variations in osteocalcin and the pituitary-gonadal axis in older men. Data were used from the Longitudinal Aging Study Amsterdam (LASA), an ongoing cohort study in a representative sample of the older Dutch population (65-88 years). Serum levels of total (T), free (FT) and bioavailable (bioT) testosterone, luteinizing hormone (LH) and osteocalcin were determined. Data were analysed using linear regression analyses and adjusted for age, BMI, 25-hydroxyvitamin D, parathyroid hormone and vitamin K antagonist use. A total of 614 men participated in the study. The median age was 75·4 (69·8-81·2) years, and the median osteocalcin level was 1·8 (1·3-2·4) nmol/l. Serum osteocalcin was inversely associated with FT (adjusted B = -0·22 ± 0·09 ng/dl, P = 0·012) and bioT (adjusted B = -0·26 ± 0·08 nmol/l, P < 0·01), but not with total T. Furthermore, osteocalcin was positively associated with LH (adjusted B = 0·09 ± 0·03 U/l, P < 0·01). Serum osteocalcin was negatively associated with free and bioavailable testosterone and positively with luteinizing hormone levels.

Expression of the androgen receptor in the testes and the concentrations of gonadotropins and sex steroid hormones in male turkeys (Meleagris gallopavo) during growth and development

Androgens, including testosterone (T) and androstenedione (A4), are essential for puberty, fertility and sexual functions. The biological activity of those hormones is mediated via the androgen receptor (AR). The regulation of androgen action in birds is poorly understood. Therefore, the present study analysed mRNA and protein expression of AR in the testes, plasma concentrations of the luteinizing hormone (LH), follicle-stimulating hormone (FSH), T, A4 and oestradiol (E2), as well as the levels of T, A4 and E2 in testicular homogenates of male turkeys (Meleagris gallopavo) at the age of 4, 8, 12, 16, 20, 24 and 28weeks. Plasma concentrations of LH and FSH, as well as plasma and testicular levels of T and A4 began to increase at 20weeks of age. The lowest plasma levels of E2 were noted at 20weeks relative to other growth stages. The 20th week of life seems to be the key phase in the development of the reproductive system of turkeys. The AR protein was found in the nuclei of testicular cells in all examined growth stages. Higher expression of AR protein in the testes beginning at 20weeks of age was accompanied by high plasma concentrations of LH and high plasma and testicular levels of androgens. This relationship seems to be necessary to regulate male sexual function.

Human Chorionic Gonadotropin Increases β-Cleavage of Amyloid Precursor Protein in SH-SY5Y Cells

Elevated levels of amyloid-β (Aβ) peptides, the main component of amyloid plaques in Alzheimer's disease, are the result of excessive β- and γ-cleavage of the amyloid precursor protein (APP) and/or impaired Aβ clearance in the brain. It has been suggested that high concentrations of luteinizing hormone (LH) in women contribute to increased Aβ generation after menopause, but the mechanism for this is incompletely understood. We investigated the effect of human chorionic gonadotropin (hCG), an LH receptor agonist, on APP β-cleavage in the SH-SY5Y neuroblastoma cell line. Treatment of these cells with hCG-induced elevated β-cleavage in a dose-dependent manner: administration of 30 mIU but not 10 mIU/ml of hCG significantly increased sAPPβ levels in the cell medium 1.7-fold as measured by ELISA. These results support the notion that LH contributes to elevated Aβ levels at least in part by increasing β-cleavage of APP by β-site APP cleaving enzyme.

Gonadotropins Are Related to Lean Mass in Healthy Postmenopausal Women

Background. It has been suggested that the changes in hormone levels that occur with menopause and aging are related to loss of muscle mass. However, the role of gonadotropins in this process is unknown. Objectives. To analyze the relationship between follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and lean mass in a cohort of healthy women. Methods. This is a cross-sectional study including 91 postmenopausal women (48–65 years old). Serum FSH, LH, and estradiol (E2) were measured. Lean mass was estimated by bioelectrical impedance analysis and expressed as appendicular skeletal muscle mass (AMM) index. Results. AMM index was negatively correlated with FSH levels (r = −0.33, p = 0.001) and LH (r = −0.293, p = 0.005), while there was no association with E2. When muscle mass expressed as AMM index was stratified into tertiles, there were significant differences between the lowest and the highest tertile for both FSH (82.4 ± 30, vs. 67.9 ± 25.8 mIU/mL, p = 0.04) and LH (40.9 ± 15.2 vs. 36.1 ± 12.3 mIU/mL, p = 0.03). In logistic regression analysis adjusted for age and E2 levels, high concentrations of FSH (OR = 1.03, 95% CI = 1.01–1.05, p = 0.008) and LH (OR = 1.06, 95% CI = 1.01–1.1, p = 0.01) were risk factors for having lower lean mass expressed as AMM index. Conclusions. Menopausal women with high levels of gonadotropins have lower levels of lean mass than those with lower gonadotropins levels.

Further Evidence of the Clinical, Hormonal, and Genetic Heterogeneity of Klinefelter Syndrome: A Study of 216 Infertile Egyptian Patients

This study aims to provide further insight into the phenotypic heterogeneity of Klinefelter syndrome (KS) by presenting clinical, hormonal, and genetic data from a large series of Egyptian infertile patients with KS. A retrospective case series of KS patients was studied over a period from January 2003 to April 2010. All patients underwent a complete history and physical examination; color duplex examination; semen analysis; measurement of total testosterone (T), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and prolactin (PRL); and chromosomal typing. Mosaic KS diagnosis was confirmed by fluorescence in situ hybridization. The series included 216 KS patients (198 nonmosaic, 16 mosaic, and 2 KS variants). Typical clinical signs of hypoandrogenism were observed in 86% of patients. Gynecomastia affected 20.8% of the patients. Eunuchoidal body proportions, with arm span exceeding height and lower segment length exceeding upper segment length, were detected in 43.9% and 64.4% of the patients, respectively. In all patients, a reduction in testicular size and azoospermia were detected. Normal levels of T, FSH, LH, E2, and PRL were detected in 44.5%, 3.7%, 3.3%, 93.5%, and 91.2% of patients, respectively. Differences were not significant between patients with classic KS and those with mosaic KS in terms of the frequency of clinical signs of hypoandrogenism, gynecomastia, low T concentrations, or high concentrations of FSH, LH, E2, and PRL (all P > .05). The results of the current study emphasize the heterogeneous clinical, hormonal, and genetic phenotype of infertile KS patients. Our findings support the usefulness of cytogenetic studies in infertile patients showing small testicular size and azoospermia, regardless of the presence of other clinical or endocrine findings.

Luteinizing hormone (LH) regulates production of androstenedione and progesterone via control of histone acetylation of StAR and CYP17 promoters in ovarian theca cells

Although luteinizing hormone (LH) affects androstenedione (A4) and progesterone (P4) production in theca cells, it is still unknown how LH influences molecular mechanism of A4 and P4 production. To examine the relationship between LH and transcription factors involved in A4 and P4 production, ovarian theca cells were cultured in the presence or absence of high concentrations of LH for 24h (pre-treatment with high concentration of LH) and then cultured in the presence or absence of low concentration of LH for 48h. Low LH enhanced production of A4 and P4, and expressions of CYP17 and StAR mRNA in theca cells without pre-treatment with high LH. In addition, low LH stimulated the expression of SF-1 protein in nuclear fractions from theca cells with or without pre-treatment with high LH. The binding of SF-1 to the CYP17 and StAR promoter regions increased in theca cells treated with low LH. Although GATA-4 and GATA-6 are both found in the nuclear fraction but not in the cytosol of theca cells, low LH enhanced the binding of GATA-6, but not of GATA-4, to the CYP17 promoter region without pre-treatment with high LH. Acetylation histone H3 in StAR and CYP17 promoter regions were changed by different LH-dosage. Overall, we showed that LH regulates the production of A4 and P4 by affecting the nuclear localization and switching of transcription factors in theca cells and that target transcription factors involved in steroid production in theca cells are changed by different LH concentration.

Aberrantly increased mRNA expression of betaglycan, an inhibin co‐receptor in the ovarian tissues in women with polycystic ovary syndrome

To compare the gene expressional levels of receptors for activins and inhibins in ovarian tissues between women with polycystic ovary syndrome (PCOS) and normal controls, and to analyze their biologically relevant associations with serum hormone levels. Total RNA of ovarian tissues from PCOS (n = 14) and normal controls (n = 21) were isolated during the follicular phase of the menstrual cycle. Real-time PCRs were performed to examine the relative mRNA expression levels of the activin receptors, including activin receptor type IA (ActRIA), type IB (ActRIB), type IIA (ActRIIA), and type IIB (ActRIIB), and the inhibin receptors, betaglycan and an inhibin binding protein (InhBP/p120). At the same time, the serum levels of estradiol (E(2)), testosterone (T), follicle-stimulating hormone (FSH), luteinizing hormone (LH), inhibin B and activin A were measured. The PCOS patients showed endocrine characteristics with higher concentrations of LH, T and inhibin B, and a lower concentration of activin A. Real-time PCR demonstrated that the relative expression level of betaglycan against that of GAPDH was increased 1.5-fold in the ovarian tissues during the follicular phase of PCOS patients when compared with normal controls, while the activin receptors ActRIA, ActRIB, ActRIIA, ActRIIB, and the inhibin co-receptor InhBP/p120 were unchanged. Moreover, the betaglycan mRNA expression showed biologically relevant associations with serum FSH, LH, E(2) and inhibin B levels in both the PCOS and normal controls. This is the first report to demonstrate the aberrantly increased expression of betaglycan mRNA in PCOS ovaries. The mechanism by which betaglycan contributes to the pathologic process of PCOS remains to be clarified.

Alterations of the pituitary-ovarian axis in dogs with a functional granulosa cell tumor

Information on the pituitary-ovarian axis in dogs with a granulosa cell tumor (GCT) is lacking. Therefore, we investigated the plasma concentrations of luteinizing hormone (LH) and estradiol before and after gonadotropin-releasing hormone (GnRH) administration in seven bitches with a functional GCT (GCT-total), of which three were intact (GCT-intact) and four had remnant ovarian tissue (GCT-ROT). The results of the GnRH stimulation test were compared with those in six anestrous and six ovariectomized bitches. The most noteworthy results were as follows. The basal plasma LH concentrations of the GCT-ROT bitches were higher (P < 0.05) than those of the anestrous bitches. The increment in the plasma LH concentration after GnRH administration in the GCT-total bitches was lower (P < 0.001) than the increments in both the anestrous and ovariectomized bitches. The basal plasma estradiol concentrations in the GCT-total bitches were higher (P < 0.001) than those in the anestrous and ovariectomized bitches. In conclusion, the pituitary-ovarian axis is affected in bitches with a functional GCT and is characterized by relatively high plasma LH concentrations in GCT-ROT bitches and a subnormal LH response to GnRH stimulation in all GCT bitches compared with those in anestrous and ovariectomized bitches. The relatively high proportion of dogs with remnant ovarian tissue among the GCT bitches suggests a pathogenetic role for elevated gonadotropin secretion in the pathogenesis of GCT.

Effect of melatonin implants on sexual activity in Mediterranean goat females without separation from males

This work was designed to determine whether melatonin treatment at the spring equinox can induce reproductive activity in goats without separation from males (separation being the normal practice in Spanish farming systems) and whether this treatment modifies the onset of the natural breeding season. Twenty-nine entire does were distributed into two groups (Group M, n = 14; Group C, n = 15). A third group of ovariectomized, estradiol-treated goats (OVX group, n = 5) was used to study the effect of melatonin on reproductive activity. On March 18, Groups M and OVX received a subcutaneous melatonin implant. In entire females, estrus was tested daily using entire aproned males, and ovulation rate was assessed after identification of estrus. Plasma progesterone in entire goats, plasma luteinizing hormone (LH) in the OVX group, and live weight and body condition score for all animals were recorded once a week. In entire goats, a clear treatment by time interaction was observed for progesterone concentrations (P < 0.001), with a period of high progesterone concentrations during the natural seasonal anestrus in Group M. A similar period of high LH concentrations was observed in the OVX group. Whereas all females of Group M presented ovarian activity during this period, no female of Group C did. The resumption of the natural breeding season was retarded in Group M in comparison with that in Group C (P < 0.05). We can conclude that in Mediterranean goats, melatonin implants can induce reproductive activity without separation from males, and it causes a small retardation in the reactivation of reproductive activity in the natural breeding season.

Immunization Against Vasoactive Intestinal Peptide and its Effects on Prolactin, Steroid, Luteinizing Hormone and Egg Production During Mid Laying Cycle in Punjab Brown (PB3 ) Birds

Objective of the study is examine the effects of active immunization against chicken Vasoactive Intestinal Peptide (chVIP) on plasma prolactin (PRL) concentration, concentration of luteinizing hormone (LH) profile its interval and duration, Progesterone (P ), Estradiol (E s), intersequence pause days and egg 4 2 production in birds during the later stages of egg production from 48-72 weeks of egg lay in PB3 birds. Twenty-four PB3 birds of same age group were divided into 2 groups of 12 in each. Birds in control group were administered s/c with placebo. Equal volume of chVIP immunogenic protein was administered to treated group from 17 week of age to 36 weeks of age at an interval of 4 weeks. Hormonal profiles of th immunized and control birds were quantified at weekly intervals from 48th to 72nd weeks of age in both the groups for prolactin, LH, estradiol, progesterone. Egg production and pause days were recorded in both the groups. At 59th weeks of age, blood samples from chVIP immunized and control birds were obtained every 4 h for 48 h to study the surges of LH. In immunized PB3 birds (against ch VIP) plasma PRL concentration was lower (p<0.01) with high concentrations of E s, P , LH and its 4 h LH surges in plasma. Significantly 2 4 (p<0.01) higher egg production (13.62%) and less pause days were observed in chVIP immunized birds. It is mainly attributed due to low PRL concentration, associated with high concentrations of LH (with regular interval and duration of LH surges), Es and P concentration required for egg formation and subsequent 2 4 ovulation. In conclusion, chVIP immunization advanced the LH surges, for release of matured oocyte, egg formation and egg lay enabled the birds to lay eggs at regular intervals due to active immunization against chVIP. Results indicate that control of chVIP may lead to more egg production with shorter duration of LH surges.

Prolactin, Luteinizing Hormone and Steroid Hormone Concentration in Punjab Brown (PB3) Birds Immunized Against Vasoactive Intestinal Peptide During the Early Stages of Egg Production

This study aims at the effects of active immunization against chicken Vasoactive Intestinal Peptide (chVIP) on plasma prolactin (PRL) concentration, concentration of Luteinizing Hormone (LH) profile its interval and duration, progesterone (P ), estradiol (E s), intersequence pause days and egg production in 4 2 birds during the initial stages of egg production from 20-36 weeks of egg lay in PB3 birds. Twenty-four PB3 birds of same age group were divided into two groups of twelve in each. Birds in control group were administered s/c with placebo. Equal volume of chVIP immunogenic protein was administered to treate d group from 17th week of age to 36 weeks of age at an interval of four weeks. Hormonal profiles of immunized and control birds were quantified at weekly intervals from 17th to 36th weeks of age in both the groups for prolactin, LH, estradiol, progesterone. Egg production and pause days were recorded in both the groups. At 31st weeks of age, blood samples from chVIP immunized and control birds were obtained every 4 h for 48 hours to study the surges of LH. In immunized PB3 birds (against ch VIP) plasma PRL concentration was lower (p<0.01) with high concentrations of E s, P , LH and, its 4h LH surges, in plasma (p<0.01). Significantly 2 4 higher egg production (9.71%), less pause days were observed in chVIP immunized birds. It is mainly attributed due to low PRL concentration, associated with high concentrations of LH (with regular interval and duration of LH surges), E s and P concentration required for egg formation and subsequent ovulation. In 2 4 conclusion, chVIP immunization advanced the LH surges, for release of matured oocyte, egg formation and egg lay enabled the birds to lay eggs at regular intervals due to active immunization against chVIP. Results indicate that control of chVIP may lead to more egg production with shorter duration of LH surges.

Effect of suppression of plasma prolactin on luteinizing hormone concentration, intersequence pause days and egg production in domestic hen

The aim of this study was to investigate the effects of suppression of plasma prolactin (PRL) concentration on circulating concentrations of luteinizing hormone (LH), progesterone (P 4), estradiol (E 2β), pause days and egg production in birds later in the reproductive period. Twenty-four White Leghorn birds of same age group were divided into two groups of 12 in each. Birds of each group were administered s/c either with placebo (control group) or equal volumes of anti PRL agent (2-bromo-α-ergocriptine) solution containing at 100 μg/kg body weight/hen/week (treated group) from 72 to 82 weeks of age. Egg production and inter sequence pauses were recorded daily from both the groups. Plasma PRL, LH, E 2β and P 4 concentrations were estimated in blood samples collected at weekly intervals. At 77th weeks of age, blood samples from treated and control birds were obtained every 3 h for 36 h to study the surges of LH. It was found that plasma PRL concentration was lower ( p < 0.01) in bromocriptine treated birds with high concentrations of LH, its 3 h LH surges, E 2β and P 4 in plasma. Higher egg production, less pause days in treated birds may be the result of low PRL concentration, associated with positively correlated responses of high concentrations of LH (with regular interval and duration of LH surges), E 2β and P 4 concentration required for completion of egg formation and oviposition. In conclusion, bromocriptine administration decreased ( p < 0.01) PRL concentration increased ( p < 0.01) steroid hormones and LH surges, for egg formation and oviposition and enabled the birds to lay more eggs even later in the productive period with the available resources under normal husbandry practices.