Maternal physiology

Oxytocin, a nine amino acid peptide, is synthesized primarily in the paraventricular and supraoptic (SON) nuclei of the hypothalamus, from which it is released to the general circulation through the posterior pituitary (Insel et ah, 1997). However, oxytocinergic fibers have also been found to project from the PVN to the limbic system and several autonomic centers in the brain stem. This central OT pool appears to be independent of pituitary OT release cerebrospinal fluid (CSF) and plasma OT responses to numerous stimuli are not correlated (Insel, 1997). Oxytocin and its analog (or partner) peptide vasopressin are found only in mammals. A related peptide, vasotocin, thought to be the evolutionary precedent of these peptides, is found in reptiles and birds. The first known actions of OT were its peripheral effects on the physiology of new mothers. In mammals, OT stimulates milk ejection and uterine contraction, essential aspects of maternal physiology (Insel et ah, 1997). 

Q6 What are the major changes in maternal physiology during pregnancy ... 

In addition to the classical stress hormones already reviewed, several other hormones are augmented in response to stress. Stress-induced prolactin release is one of the most frequently studied examples. There is no doubt about the causal relationship between stress and increased pituitary prolactin release, but the biological meaning is much less clear (G2). This phylogenetically old hormone has been shown to have more than 85 different functions in all vertebrate species. However, besides its role in the induction of maternal lactogenesis, the physiological importance of prolactin is at present not fully established. Experimental and clinical evidence supports the view that prolactin is also an immunoregulating hormone (M44, R18). Prolactin receptors are present on human T and B lymphocytes (R18), and T lymphocytes depend on prolactin for maintenance of immunocompetence (B19). In addition, it has been shown that prolactin is able to influence the devel-... 

Nichols, J.W., K.M. Jensen, J.E. Tietge, and R.D. Johnson. 1998. Physiologically based toxicokinetic model for maternal transfer of 2,3,7,8-tetrachlorodibenzo-p-dioxin in brook trout (Salvelinus fontinalis). Environ. Toxicol. Chem. 17 2422-2434. 

Various autonomic, physiological and behavioral effects of oxytocin could contribute to the development and expression of maternal behavior (Uvnas-Moberg, 1996). Para-... 

Numan, M. Maternal behavior. In The Physiology of Reproduction. Second Edition. Ed. E. Knobil and J. D. Neill. New York Raven Press, pp. 221-302. 

Pryce, C. R., Abbott, D. H., Hodges, J. K., and Martin, R. D. 1988. Maternal behavior is related to prepartum urinary estradiol levels in red-bellied tamarin monkeys. Physiology and Behavior 44 717-726. 

Dickinson, C. and Keverne, E. B. (1988). Importance of noradrenergic mechanisms in the olfactory bulbs for the maternal behavior of mice. Physiology and Behavior 43, 313-316. 

Leon, M. (1975). Dietaiy control of maternal pheromone in the learning rat. Physiology and Behavior 14,311-319. 

Lepri, J.J., Wysocki, C.J., and Vandenbergh,J.G. (1985). Mouse vomeronasalorgan effects on pheromone production and maternal behavior. Physiology and Behavior 35, 809-814. 

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