Testicular morphometry as a tool to evaluate the efficiency of immunocastration in lambs

This study aimed to evaluate the efficiency of immunocastration in lambs using testicular morphometry. Thirty lambs were randomly divided into two treatments (subcutaneous administration of 1.0 mL and 0.5 mL of an anti-GnRH vaccine) and a control group (1.0 mL saline solution). The animals were vaccinated at four months of age, received a second dose 30 days later, and were slaughtered 90 days after the first vaccine dose. After slaughter, testicles were collected, and samples were removed for histological processing and evaluation of testicular morphometric parameters. Analysis of variance, Tukey's test, and Kruskal-Wallis test were performed, with a 5% level of significance. There was a reduction in testicular weight, gonadosomatic index, seminiferous tubule diameter, germinal epithelium height, leydigosomatic index, and total tubule length. The total length per testicular gram increased in the immunocastrated group. Intrinsic spermatogenesis yield, Sertoli cell indices, and estimates of sperm and Sertoli cell production were reduced in the immunized groups (P < 0.05). The anti-GnRH vaccine in lambs at doses of 1.0 mL and 0.5 mL is sufficient to promote immunocastration, verified through severe changes in testicular morphometry from animals.(AU)

Seasonal changes in hypothalamic gonadotropin inhibitory hormone expression in the paraventricular nucleus of chukar partridge (Alectoris chukar)

Gonadotropin inhibitory hormone (GnIH) as a hypothalamic neuropeptide inhibits the synthesis and release of gonadotropins via affecting gonadotropin releasing hormone (GnRH) neurons and could be a key neuropeptide in regulating seasonal breeding in birds. The aim of the present study was to investigate the expression of GnIH in the hypothalamus of male and female chukar partridges (Alectoris chukar) during the breeding and non-breeding seasons. In breeding (May) and non-breeding (January) seasons, the brains of sexually-matured male (n = 10) and female (n = 10) chukar partridges were removed following fixation. Sections (30 μm) were prepared from the entire diencephalon and stained immunohistochemically. GnIH-immunoreactive neurons were primarily found in paraventricular nucleus, and few positive neurons were detected in dorsomedial nucleus. The numbers of GnIH-immunoreactive neurons were significantly lower in the breeding season compared with the non-breeding season in both male and female (P < 0.05). There were no significant differences in the number of GnIH neurons in paraventricular nucleus between the sexes. Gonadal weight and volume in male and female partridges were significantly higher in the breeding season. The results showed that GnIH neurons may partly contribute to the regulation of the seasonal breeding in the chukar partridge.(AU)

Seasonal changes in hypothalamic gonadotropin inhibitory hormone expression in the paraventricular nucleus of chukar partridge (Alectoris chukar)

Gonadotropin inhibitory hormone (GnIH) as a hypothalamic neuropeptide inhibits the synthesis and release of gonadotropins via affecting gonadotropin releasing hormone (GnRH) neurons and could be a key neuropeptide in regulating seasonal breeding in birds. The aim of the present study was to investigate the expression of GnIH in the hypothalamus of male and female chukar partridges (Alectoris chukar) during the breeding and non-breeding seasons. In breeding (May) and non-breeding (January) seasons, the brains of sexually-matured male (n = 10) and female (n = 10) chukar partridges were removed following fixation. Sections (30 μm) were prepared from the entire diencephalon and stained immunohistochemically. GnIH-immunoreactive neurons were primarily found in paraventricular nucleus, and few positive neurons were detected in dorsomedial nucleus. The numbers of GnIH-immunoreactive neurons were significantly lower in the breeding season compared with the non-breeding season in both male and female (P < 0.05). There were no significant differences in the number of GnIH neurons in paraventricular nucleus between the sexes. Gonadal weight and volume in male and female partridges were significantly higher in the breeding season. The results showed that GnIH neurons may partly contribute to the regulation of the seasonal breeding in the chukar partridge.

La proporción de formas moleculares de gonadotropinas se altera en pacientes con síndrome de ovarios poliquísticos / The proportion of gonatropins molecular forms is altered in patients with polycystic ovaries syndrome

En general las hormonas protéicas circulan como varias formas moleculares con actividad biológica diferentes y su proporción sufre modificaciones de acuerdo al ambiente hormonal en que se encuentra, tanto en condiciones fisiológicas como patológicas. Las gonadotropinas, tanto LH como FSH, en condiciones naturales de hipoestrogenismo como es durante la menopausia, presentan las formas moleculares grandes como las predominantes y este perfil cromatográfico en suero muestra un cambio a las formas moleculares intermedias cuando de administran estrógenos. Durante un ciclo ovulatorio se puede demostrar la predominancia, alrededor de la ovulación, de las isoformas de peso intermedio que son las más activas biológicamente. En el presente trabajo se tomó como modelo de estudio a mujeres con ciclos anovulatorios con el diagnóstico de síndrome Leventhal y se encontró que después de un sangrado menstrual inducido con un progestágeno, el perfil cromatográfico era polimorfo e irregular, lo cual fue comparado con el perfil cromatográfico obtenido en el suero de mujeres durante un ciclo ovulatorio. En este último se observó la predominancia de las formas intermedias de LH y FSH en el día 14 del ciclo por lo cual se puede concluir que las isoformas biológicamente más activas de las gonadotropinas constituyen la mayor proporción durante una etapa crucial como es la periovulatoria

Macroadenomas näo-funcionantes da hipófise: estudo imuno-histoquímico / Functionless pituitary macroadenomas: immunohistochemical study

Cinqüenta e nove adenomas hipofisários, do tipo nao-funcionante, foram analisados pelo método imuno-histoquímico. Os tumores foram estudados através da técnica da peroxidase - avidina - biotina (ABC) e pesquisados os seguintes hormônios, com anticorpos primários específicos: prolactina (PRL), hormônio do crescimento (HS), corticotrofina (ACTH), gonadotrofinas (HCG) e tireotrofina (TSH). Trinta e oito tumores nao reagiram a nenhum anticorpo, 8 tumores apresentaram imunorreaçao positiva à prolactina, 5 tumores eram imunorreativos ao HS, 6 eram imunorreativos ao ACTH, e 10 tumores eram imunorreativos às gonadrotofinas, sendo que 5 ao LH e 5 ao FSH. Dos tumores que apresentaram imunorreatividade ao hormônio do crescimento e à prolactina houve manifestaçao clínica em apenas um, cujo paciente evoluiu com altas taxas de prolactina sangüínea.

Equine growth hormone. Detection of immunoreactive sequences using poly- and monoclonal antibodies.

The immunochemical behavior of several fragments of equine growth hormone (eGH) was examined using competitive binding assays with antibodies (Abs) to eGH obtained from different sources. Antigenicity was detected within the sequences 5-72 and 73-123 by rabbit Abs to eGH and by three mouse monoclonal antibodies (MAbs) produced by using bovine growth hormone as immunogen, but showing heteroclitic properties towards eGH. The polyclonal Abs to eGH also recognized as immunoreactive two smaller peptides corresponding to the amino acid residues 52-72 and 110-123. By contrast, the heteroclitic Abs to eGH developed by hypopituitary patients therapeutically injected with human growth hormone failed to react with any eGH-derived fragment. The rabbit polyclonal Abs and the mouse MAbs scarely discriminated between native and S-carbamidomethylated eGH, while the heteroclitic human Abs detected a clear difference between the native and the modified hormone.