Age-related changes in peripheral hormone concentrations and their relationships with testis size and number of Sertoli and germ cells in yearling beef bulls

Moura, Araripe; Erickson, B. H.

doi:10.1530/jrf.0.1110183

Cited by 46 publications

(26 citation statements)

References 23 publications

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“…The relationship between reduced FSH and delayed postnatal activation of the reproductive axis observed in the pubertal and postpubertal LPeri cohort concurs with previous research: FSH levels, along with LH, rise transiently between 1 and 4 months of age in the prepubertal bull (Rawlings et al 1978;Evans et al 1996;Moura and Erickson 1997;Kaneko et al 2001;Bagu et al 2006), a rise reported to be associated with the initiation of rapid testis growth (Moura and Erickson 1997). FSH levels then fall, remaining low during peri-puberty and puberty (Moura and Erickson 1997;Kaneko et al 2001;Brito et al 2007cBrito et al , 2007d.…”

Section: Postnatal Developmentsupporting

confidence: 90%

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Peri-conception and first trimester diet modifies reproductive development in bulls

Copping

Ruiz-Diaz

Mongan

et al. 2018

Reprod. Fertil. Dev.

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Abstract. Nutritional perturbation during gestation alters male reproductive development in rodents and sheep. In cattle both the developmental trajectory of the feto-placental unit and its response to dietary perturbations is dissimilar to that of these species. This study examined the effects of dietary protein perturbation during the peri-conception and first trimester periods upon reproductive development in bulls. Nulliparous heifers (n ¼ 360) were individually fed a high-or low-protein diet (HPeri and LPeri) from 60 days before conception. From 24 until 98 days post conception, half of each treatment group changed to the alternative post-conception high-or low-protein diet (HPost and LPost) yielding four treatment groups in a 2 Â 2 factorial design. A subset of male fetuses (n ¼ 25) was excised at 98 days post conception and fetal testis development was assessed. Reproductive development of singleton male progeny (n ¼ 40) was assessed until slaughter at 598 days of age, when adult testicular cytology was evaluated. Low peri-conception diet delayed reproductive development: sperm quality was lowered during pubertal development with a concomitant delay in reaching puberty. These effects were subsequent to lower FSH concentrations at 330 and 438 days of age. In the fetus, the low periconception diet increased the proportion of seminiferous tubules and decreased blood vessel area in the testis, whereas low first trimester diet increased blood vessel number in the adult testis. We conclude that maternal dietary protein perturbation during conception and early gestation may alter male testis development and delay puberty in bulls.

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Section: Postnatal Developmentsupporting

confidence: 90%

“…FSH levels then fall, remaining low during peri-puberty and puberty (Moura and Erickson 1997;Kaneko et al 2001;Brito et al 2007cBrito et al , 2007d. In the adult, FSH levels increase as bulls age in association with improvement in sperm quality and quantity (Matsuzaki et al 2000).…”

Section: Postnatal Developmentmentioning

confidence: 99%

Peri-conception and first trimester diet modifies reproductive development in bulls

Copping

Ruiz-Diaz

Mongan

et al. 2018

Reprod. Fertil. Dev.

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“…As diferenças nos níveis de T entre as coletas realizadas 1,5 e 3,0 horas após a aplicação do GnRH foram reduzidas e significativas somente entre 17 e 21 meses de idade (P<0,05; Figura 5). Resultados semelhantes foram encontrados por Moura & Erickson (1997), em touros de corte de sub-espécie Bos taurus taurus entre as fases de pré-e pós-puberdade. Oba et al (1989) verificaram que os níveis máximos de testosterona ocorreram entre 1 e 3 horas após tratamentos com GnRH, em um grupo de touros da raça Nelore com 18 a 26 meses de idade.…”

Section: Concentrações Periféricas De Testosteronaunclassified

“…T0: concentrações basais de tesotosterona T1,5; T3,0: concentrações de testosterona avaliadas 1,5 e 3,0 horas após a aplicação de GnRH, realizada no período T0. maior magnitude em todas as idades (r = 0,53 a 0,85, P<0,01), resultados semelhantes àqueles descritos por Moura & Erickson (1997) em animais da subespécie Bos taurus taurus. Houve também correlações entre as concentrações basais de testosterona e aquelas determinadas após o tratamento com GnRH (r = 0,41 a 0,63; P<0,05), porém estas correlações foram menores que as descritas por Moura & Erickson (1997) (r = 0,64 a 0,75).…”

Section: Concentrações Periféricas De Testosteronaunclassified

“…maior magnitude em todas as idades (r = 0,53 a 0,85, P<0,01), resultados semelhantes àqueles descritos por Moura & Erickson (1997) em animais da subespécie Bos taurus taurus. Houve também correlações entre as concentrações basais de testosterona e aquelas determinadas após o tratamento com GnRH (r = 0,41 a 0,63; P<0,05), porém estas correlações foram menores que as descritas por Moura & Erickson (1997) (r = 0,64 a 0,75). A razão pela qual, no presente estudo, as correlações entre os níveis basais de T e os estimulados com GnRH foram menos expressivas está associada ao fato de que a testosterona é secretada em pulsos (Amann & Schanbacher, 1983) e uma única amostra de soro sangüíneo pode, às vezes, não expressar todo o potencial de secreção hormonal do animal, no momento da coleta.…”

Section: Concentrações Periféricas De Testosteronaunclassified

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Desenvolvimento ponderal e testicular, concentrações periféricas de testosterona e características de abate em touros da raça Nelore

2002

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RESUMO -Um experimento foi conduzido com o objetivo de avaliar o desenvolvimento ponderal e testicular, as concentrações periféricas de testosterona (T) e características de abate, dos 10 aos 30 meses de idade, em tourinhos da raça Nelore (n=27). Entre 11 e 21 meses, os animais foram tratados com GnRH e amostras de sangue, coletadas 0, 1,5 e 3,0 horas depois. Aos 30 meses, os animais foram abatidos. O peso vivo (PV) dos animais variou de 195,2 ± 3,8 kg a 439,1 ± 8,1 kg entre 10 e 30 meses e o rendimento de carcaça foi de 55,4 ± 2,3%. Os pesos dos testículos (PT) e do epidídimo (PE) aos 30 meses foram 160,9 ± 7,7 g e 20,4 ± 0,62 g, respectivamente.As concentrações de T apresentaram crescimento maior entre 16 e 18 meses e o tratamento com GnRH ocasionou aumentos nos níveis de T em todas as idades. As concentrações de testosterona estimuladas com GnRH estiveram associadas às concentrações basais (r = 0,41 a 0,63). Houve correlações entre PV e circunferência escrotal (CE) em todas as idades (r = 0,41 a 0,70). O peso corporal entre 10 e 30 meses apresentou correlações com PT (r = 0,48 a 0,62) e PE (r = 0,48 a 0,73) aos 30 meses e animais com maior peso de carcaça também tiveram maiores pesos testicular (r = 0,45) e epididimal (r = 0,63). Houve correlações entre PV (10 e 30 meses) e peso da carcaça (r = 0,65 a 0,93), mas o rendimento de carcaça não apresentou relação com CE, PT, PV ou níveis de testosterona. Foram significativas também as correlações entre a CE aos 30 meses e a CE avaliada entre 10 e 25 meses (r = 0,51 a 0,89). Portanto, medidas testiculares são potenciais indicadores do desenvolvimento ponderal e das características de abate na fase adulta.Palavras-chave: carcaça, circunferência escrotal, GnRH, Nelore, testosterona Testicular and Body Growth, Peripheral Concentrations of Testosterone and Carcass Parameters in Nelore BullsABSTRACT -An experiment was carried out to evaluate testicular and body growth, peripheral concentrations of testosterone (T) and carcass parameters, from 10 to 30 months of age, in Nelore bulls (n=27). Between 11 and 21 months, animals were treated with GnRH and blood samples taken 0, 1.5 and 3.0 hours afterwards. Animals were slaughtered at 30 months. Body weight (BW) varied from 195.2 ± 3.8 kg to 439.1 ± 8.1 kg between 10 and 30 months of age and the ratio BW/carcasss was 55.4 ± 2.3%. Testicular (TW) and epididimal weight (EW) at slaughter were 160.9 ± 7.7 g and 20.5 ± 0.62 g, respectively. Testosterone secretion reached higher levels between 16 and 18 months and treatment with GnRH caused increases in testosterone at all ages. Moreover, basal concentrations of T were related to those determined after GnRH (r = 0.41 to 0.63). Body weight from 10 to 30 months was correlated with SC at all ages (r = 0.41 to 0.70) and with testicular (r = 0.48 to 0.62) and epididymal weight (r = 0.48 to 0.73) at 30 months. Carcass weight was related to TW (r = 0.45) and EW (r = 0.63). Body weight evaluated from 10 to 30 months was related to carcass weight (r = 0.65 to 0.93), but the ratio BW/carcass...

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Expression of retinol‐binding protein and cellular retinol‐binding protein in the bovine ovary

Brown

Eberhardt

Schrick

et al. 2003

Molecular Reproduction Devel

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Retinol (vitamin A) is essential for reproduction, and retinoids have been suggested to play a role in ovarian steroidogenesis, oocyte maturation, and early embryonic development. Retinol is transported systemically and intercellularly by retinol-binding protein (RBP). Within the cell, cellular retinol-binding protein (CRBP) functions in retinol accumulation and metabolism. Since the actions of retinoids are mediated, in part, by retinoid-binding proteins, the objective of this study was to investigate cell-specific expression of RBP and CRBP in the bovine ovary. Immunocytochemical analysis (ICC) localized RBP to the thecal and granulosa cell layers of antral and preantral follicles with the most intense staining in the cells of large, healthy follicles. The tunica adventitia of arterial blood vessels also exhibited RBP staining. Immunostaining of CRBP was most intense in the granulosa cells of preantral follicles and present, but diminished, in thecal and granulosa cells of antral follicles. Within the corpus luteum, both proteins were observed in large luteal cells, but only RBP was observed in small luteal cells. Northern blot analysis demonstrated that thecal and granulosa cells from antral follicles and luteal tissue expressed RBP and CRBP mRNA. Synthesis and secretion of RBP by thecal cells, granulosa cells, and luteal cells were demonstrated by immune-complex precipitation of radiolabeled RBP from the medium of cultured cells or explants, followed by SDS-PAGE and fluorography. Follicular fluid was collected from small (<5 mm) and large (8-14 mm) follicles, pooled according to follicular size, and analyzed for retinol, RBP, estradiol-17beta, and progesterone. Concentrations of retinol, RBP, and estradiol were greater in the fluid of large follicles. Results demonstrate retinoid-binding protein expression by bovine ovaries and provide physical evidence that supports the concept that retinoids play a role in ovarian function.

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Age-related changes in peripheral hormone concentrations and their relationships with testis size and number of Sertoli and germ cells in yearling beef bulls

Cited by 46 publications

References 23 publications

Peri-conception and first trimester diet modifies reproductive development in bulls

Peri-conception and first trimester diet modifies reproductive development in bulls

Desenvolvimento ponderal e testicular, concentrações periféricas de testosterona e características de abate em touros da raça Nelore

Expression of retinol‐binding protein and cellular retinol‐binding protein in the bovine ovary

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