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عنوان انگلیسی مقاله:
Nutritional control of puberty in the bovine female: prenatal and early postnatal regulation of the neuroendocrine system
ترجمه فارسی عنوان مقاله:
کنترل تغذیه ای بلوغ در گاو های ماده : تنظیم پیش از تولد و زودرس پس از زایمان سیستم عصبی و غدد درونریز
Sciencedirect - Elsevier - Domestic Animal Endocrinology, Corrected proof, 106434. doi:10.1016/j.domaniend.2020.106434
R.C. Cardosoa,*, S.M. Westa, T.S. Maiaa,b, B.R.C. Alvesa, G.L. Williamsa,b
Puberty is a complex biological event that requires maturation of the reproductive
neuroendocrine axis and subsequent initiation of high-frequency, episodic release of GnRH
and LH. Nutrition is a critical factor affecting the neuroendocrine control of puberty.
Although nutrient restriction during juvenile development delays puberty, elevated rates
of body weight gain during this period facilitate pubertal maturation by programming
hypothalamic centers that underlie the pubertal process. Recent findings suggest that
maternal nutrition during gestation can also modulate the development of the fetal
neuroendocrine axis, thus influencing puberty and subsequent reproductive function.
Among the several metabolic signals, leptin plays a critical role in conveying metabolic
information to the brain and, consequently, controlling puberty. The effects of leptin on
GnRH secretion are mediated via an upstream neuronal network because GnRH neurons
do not express the leptin receptor. Two neuronal populations located in the arcuate nucleus
that express the orexigenic peptide neuropeptide Y (NPY), and the anorexigenic
peptide alpha melanocyte-stimulating hormone (aMSH), are key components of the
neurocircuitry that conveys inhibitory (NPY) and excitatory (aMSH) inputs to GnRH neurons.
In addition, neurons in the arcuate nucleus that coexpress kisspeptin, neurokinin B,
and dynorphin (termed KNDy neurons) are also involved in the metabolic control of puberty.
Our studies in the bovine female demonstrate that increased planes of nutrition
during juvenile development lead to organizational and functional changes in hypothalamic
pathways comprising NPY, proopiomelanocortin (POMC, the precursor of aMSH),
and kisspeptin neurons. Changes include alterations in the abundance of NPY, POMC, and
Kiss1 mRNA and in plasticity of the neuronal projections to GnRH neurons. Our studies also
indicate that epigenetic mechanisms, such as modifications in the DNA methylation
pattern, are involved in this process. Finally, our most recent data demonstrate that
maternal nutrition during gestation can also induce morphological and functional changes
in the hypothalamic NPY system in the heifer offspring that are likely to persist long after
birth. These organizational changes occurring during fetal development have the potential
to not only impact puberty but also influence reproductive performance throughout
adulthood in the bovine female.
Keywords: Heifers | Hypothalamus | Leptin | Nutrition | Puberty