UNASSIGNED: @entity1 milk (HM) contains a complex array of hormones, including members of the glucocorticoid family. The predominant glucocorticoids, @entity701 and @entity821 may influence the growth and behaviour of the breastfed @entity1 . However, little is understood of the factors regulating the levels of these hormones within HM. The aim of the study was to examine HM @entity701 and @entity821 concentration, measured in samples collected at each feed during a 24  hour period. Twenty three exclusively breastfeeding mothers collected milk, prior to and after each breastfeeding session over 24  hour period at 3.2(1.60) months. HM @entity701 and @entity821 levels were measured using high pressure liquid chromatography mass spectroscopy. @entity821 was the predominant glucocorticoid (3.40  ng/ml), and @entity701 was detected in all samples (1.62  ng/ml). A positive correlation was found between @entity821 and @entity701 (r  =  0.61, y  =  1.93      0.24, p  <  0.0001). @entity701 and @entity821 concentrations were significantly higher in feeds in the morning (2.97  ng/ml and 4.88  ng/ml), compared to afternoon (1.20  ng/ml and 3.54  ng/ml), evening (0.69  ng/ml and 2.13  ng/ml) and night (1.59 and 3.27  ng/ml). No difference was found between glucocorticoids level of the milk expressed for collection either before or immediately after the breastfeed, or between milk collected from the left or right breast. This study shows that HM glucocorticoid concentrations exhibit a 24  hour pattern, with highest peak levels in the early morning, reflecting the circadian pattern as previously reported in plasma. Thus, HM glucocorticoid concentrations are likely to reflect those in the maternal circulation.

Variation of XXXX Milk Glucocorticoids over 24  hour Period.

@entity1 :: ('9606', 'Species') :: ['Human', 'infant'] @entity821 :: ('MESH:D003348', 'Chemical') :: ['cortisone', 'Cortisone'] @entity701 :: ('MESH:D006854', 'Chemical') :: ['Cortisol', 'cortisol']
@entity1 :: (9606,Species) :: ['Human']
