Changes in the Concentrations of Corticosteroids in the Blood of Fetal Pigs and Their Dams During Late Gestation and Labor

Abstract

Corticosteroid concentrations were determined in plasma samples obtained from chronically catheterized pig fetuses and their dams during late gestation and parturition. Mean concentrations of 14-20 ng/ml were found in fetal plasma on Days -16 to -10 before delivery and these rose to 40-60 ng/ml between Day -6 and the day of delivery. During the last 8 h of fetal life levels rose rapidly and at birth averaged 168.8 +/- 35.4 ng/ml. Maternal concentrations rose slightly during the last 3 days before delivery but increased significantly during delivery itself. Considerable variation in both the time at which the rise in fetal corticosteroids occurred and the magnitude of the rise was seen both within and between litters. Chromatographic separation indicated that the rise in fetal corticosteroids was associated with increasing cortisol concentrations rather than corticosterone. The data suggest that, while mean fetal corticosteroid concentrations increase in late pregnancy, the role of adrenal maturation of individual fetuses in the initiation of the parturition process in the pig needs further investigation.

Changes in the concentrations of glucose, non-esterifed fatty acids, urea, insulin, cortisol and some mineral elements in the plasma of the primiparous sow before, during and after induced parturition

“…As already observed by some authors [5,18,28], the level of plasma cortisol decreased rapidly after farrowing and, at the beginning of lactation, it was back to the concentrations observed at the end of gestation. However, in the present work the level of cortisol on the farrowing day was similar to the level previously reported by Randall [23], but higher than the concentration observed by Meunier-Salaiin et al [18]. This may partially be the result of differences between assays used in the laboratories, but also, between primiparous sows, which had never experienced parturition, and multiparous sows [18,23].…”

“…[5,18,28]. This rise in the concentration of plasma cortisol at parturition has already been described [5], and it has been associated with the rise in foetal cortisol [5,23] and with maternal stress [ 19]. Thus, the profile of cortisol concentration and its decrease 3 h after the start of parturition may reflect the end of cortisol production by the piglets when the last animal was bom.…”

Growth and development of adipose tissue and gut and related endocrine status during early growth in the pig: impact of low birth weight

“…In the pig, circulating levels of glucocorticoids and catecholamines are very high at birth and dramatically decrease thereafter (Kaciuba-Uscilko, 1972;Randall, 1983). Cortisol and catecholamines are potent stimulators of catabolism and one can speculate that these high levels induce mobilisation of glycogen stores immediately after birth.…”

A quantitative histological study of adrenal development during the perinatal period in intact and hypophysectomized pigs

“…They are smaller than those estimated in a previous study (Lohse and First, 1981) (Dvorak, 1972;F6vre, 1975) and of fetal cortisol (Randall, 1983). Growth of the cortex is certainly one of the main factors which could explain this characteristic feature of the perinatal period, even if it is accompanied by intracellular biochemical modifications in pigs (Lohse and First, 1981) and fetal sheep (Durand, 1987).…”

“…12 foetus, hypophysectomisés à G44 ou à G55 ont été récupérés à G94, G106 et G 112, au moins 50 jours après l'opération. L'hypophysectomie Introduction In the domestic pig, birth follows a period during which cortisol or corticosteroid levels increase exponentially in the fetal plasma (Dvorak, 1972;Fevre, 1975;Randall, 1983). This increased production of corticosteroids is due to a maturation of cortical cells and to the growth of the cortical zone (Lohse and First, 1981 The formation of the adrenals (Flint, 1900;Wiesel, 1901;Whitehead, 1903;Weymann, 1922Weymann, -1923Katznelson, 1965;Bielanska-Osuchowska, 1976) and their organization during fetal life (Katznelson, 1966;Gutte et al, 1986) has already been described in pigs.…”