scholarly journals Individual variation and the endocrine regulation of behaviour and physiology in birds: a cellular/molecular perspective

2007 ◽  
Vol 363 (1497) ◽  
pp. 1699-1710 ◽  
Author(s):  
Gregory F Ball ◽  
Jacques Balthazart
Keyword(s):  
Individual Variation ◽  
Molecular Mechanisms ◽  
Steroid Hormone ◽  
Molecular Genetic ◽  
Plasma Concentrations ◽  
Individual Variability ◽  
Receptor Expression ◽  
Endocrine Regulation ◽  
Metabolizing Enzyme ◽  
Hormone Receptor Expression

Investigations of the cellular and molecular mechanisms of physiology and behaviour have generally avoided attempts to explain individual differences. The goal has rather been to discover general processes. However, understanding the causes of individual variation in many phenomena of interest to avian eco-physiologists will require a consideration of such mechanisms. For example, in birds, changes in plasma concentrations of steroid hormones are important in the activation of social behaviours related to reproduction and aggression. Attempts to explain individual variation in these behaviours as a function of variation in plasma hormone concentrations have generally failed. Cellular variables related to the effectiveness of steroid hormone have been useful in some cases. Steroid hormone target sensitivity can be affected by variables such as metabolizing enzyme activity, hormone receptor expression as well as receptor cofactor expression. At present, no general theory has emerged that might provide a clear guidance when trying to explain individual variability in birds or in any other group of vertebrates. One strategy is to learn from studies of large units of intraspecific variation such as population or sex differences to provide ideas about variables that might be important in explaining individual variation. This approach along with the use of newly developed molecular genetic tools represents a promising avenue for avian eco-physiologists to pursue.

Effects of FSH treatment and withdrawal during proestrus on uterine proliferation and steroid hormone receptor expression in beef heifers

2021 ◽  
Vol 92 (1) ◽  
Author(s):  
Thanya Bunma ◽  
Chutikun Kanjanaruch ◽  
Nattawut Kogram ◽  
Suthipong Uriyapongson ◽  
Vilaivan Khanthusaeng ◽  
...  
Keyword(s):  
Hormone Receptor ◽  
Steroid Hormone ◽  
Receptor Expression ◽  
Steroid Hormone Receptor ◽  
Beef Heifers ◽  
Hormone Receptor Expression

scholarly journals Effects of Hormonally Active Agents on Steroid Hormone Receptor Expression and Cell Proliferation in the Myometrium of Ovariectomized Macaques

2011 ◽  
Vol 39 (3) ◽  
pp. 508-515 ◽  
Author(s):  
Georgette D. Hill ◽  
Alicia B. Moore ◽  
Grace E. Kissling ◽  
Norris D. Flagler ◽  
Elizabeth Ney ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Hormone Receptor ◽  
Steroid Hormone ◽  
Receptor Expression ◽  
Steroid Hormone Receptor ◽  
Hormone Receptor Expression

The endocrine regulation of growth during early life: a nutritional perspective

1992 ◽  
Vol 15 ◽  
pp. 47-62
Author(s):  
J. M. Bassett
Keyword(s):  
Growth Rate ◽  
Enteral Nutrition ◽  
Cellular Differentiation ◽  
Molecular Mechanisms ◽  
Plasma Concentrations ◽  
Postnatal Growth ◽  
Tissue Growth ◽  
Endocrine Regulation ◽  
Peripheral Tissues ◽  
The Status

AbstractRecent advances in molecular biology have begun to identify many of the molecular mechanisms involved in the control of cellular differentiation and subsequent growth. However, while this information may ultimately permit manipulation of animal growth it is important to remember that the most essential factor for growth remains adequate nutrition. The high correlation of growth rate with milk intake in neonates reminds us that growth is highly dependent on the rapid establishment of enteral nutrition after birth. The endocrine changes consequent on this, as well as the supply of nutrients to support metabolic homeostasis, play important rôles in determining survival.Birth is associated with dramatic changes in the secretion and plasma concentrations of many hormones (including insulin, glucagon, growth hormone (GH), triiodothyronine (T3), adrenaline and cortisol among others). However, while changes in secretion at this time may be of great significance for survival and adaptation during the perinatal period, after this it is only changes in the secretion of insulin and GH which appear closely related to neonatal growth. Sixty percent or more of variation in live-weight gain among lambs during the 1st month of life is positively associated with variation in plasma insulin levels, while associations with GH are strongly negative, despite the evidence for essentiality of GH as a promoter of insulin-like growth factor-1 (IGF-1) production. Observations on other species are consistent with those in lambs.Investigations in foetal lambs have established that insulin's crucial rôle as a primary regulator of anabolic metabolism and growth begins well before birth. However, while birth does not alter this important rôle, the establishment of enteral nutrition changes the way in which its secretion is modulated and increases its rôle as the principal endocrine regulator of glucose homeostasis. Secretion of gastrointestinal hormones in response to the first food plays an important rôle in this, modulating the secretion of insulin and promoting gut development through trophic actions on the mucosa. Insulin itself, also appears to have trophic effects on the liver and is probably an important determinant of nutritionally mediated alterations in hepatic IGF-1 production. Plasma IGF-1 concentrations, like those of insulin, are highly correlated with the rate of postnatal growth, but unlike insulin, the status of plasma IGF-1 as a direct regulator of cellular growth remains controversial. IGF-1 and the large molecular weight proteins to which it is bound in plasma are synthesized by many peripheral tissues as well as the liver and it seems likely that IGF-1, in association with other specific growth factors, acts principally in the extravascular compartment, as a local paracrine/autocrine regulator of cellular differentiation and growth. Whatever the status of the plasma IGF-1 pool its concentration appears to act as a useful index of the rate of tissue growth. While GH is essential for normal postnatal growth and the production of IGF-1, it does not appear rate-limiting in relation to nutritionally determined variations in growth rate. This contrasts strikingly with its rôle in growth manipulation.

Steroid hormone receptor expression and action in bone

2000 ◽  
Vol 98 (2) ◽  
pp. 217-240 ◽  
Author(s):  
Rosemary BLAND
Keyword(s):  
Steroid Hormones ◽  
Hormone Receptor ◽  
Bone Cells ◽  
Steroid Hormone ◽  
Hormonal Control ◽  
Receptor Expression ◽  
Bone Architecture ◽  
Steroid Hormone Receptor ◽  
Hormone Action ◽  
Hormone Receptor Expression

The skeleton is a complex tissue, and hormonal control of bone remodelling is elaborate. The important role that steroid hormones play in bone cell development and in the maintenance of normal bone architecture is well established, but it is only relatively recently that it has become possible to describe their precise mechanism of action. This review focuses not only on the steroid hormones (oestrogens, corticosteroids, androgens and progesterone), but also on related hormones (vitamin D, thyroid hormone and the retinoids), all of which act via structurally homologous nuclear receptors that form part of the steroid/thyroid receptor superfamily. By examining the actions of all of these hormones in vivo and in vitro, this review gives a general overview of the current understanding of steroid hormone action in bone. In addition, a comprehensive review of steroid hormone receptor expression in bone cells is included. Finally, the role that future developments, such as steroid hormone receptor knockout mice, will play in our understanding of steroid hormone action in bone is considered.

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