Cyclic 3′,5′-Adenosine Monophosphate in Umbilical Cord Blood of the Newborn Infant: Relation to Fetal Stress and Plasma Catecholamines

Abstract

Cyclic 3′,5′-adenosine monophosphate (cyclic AMP) was analyzed in the venous blood of the mothers and in the umbilical vein and artery of the infant at birth. In general, higher cyclic AMP levels were found in the umbilical vein than in the artery which were similar to the maternal values. Asphyxia and vacuum extraction were associated with significantly higher cyclic AMP levels, while the concentration was lower after elective cesarean sections than after uncomplicated vertex deliveries. The cyclic AMP concentrations were inversely correlated to pH and directly related to the catecholamine concentrations. The origin and possible significance of cyclic AMP in umbilical cord plasma is discussed.

Plasma Levels of Adenosine 3′,5′-Monophosphate in the Fetoplacental Unit and Maternal Circulation at Delivery

“…The group of neonates investigated in the latter study, however, was composed of a mixed population: the infants were born following different types of deliveries and were of vari able gestational age and birth weight. This may explain the discrepancy between our data and those of Bisto/etti et al [7], It should also be noted that in the present study, in contrast to others [6,7], we ascertained that the blood specimens were indeed obtained from the UA or UV (by assaying progester one concentration).…”

“…The markedly increased UA cAMP plasma concentration at term relative to the concentration in MV, as well as the arteriove nous gradient of plasma cAMP level in the fetoplacental circulation, strongly suggest that the high cAMP levels in the cord blood originate mainly from the fetus. Our results are in agreement with the data of Yuen et al [6], but diverge from those of Bistoletti et al [7] who concluded that higher cAMP levels were found in the UV than in the UA. The group of neonates investigated in the latter study, however, was composed of a mixed population: the infants were born following different types of deliveries and were of vari able gestational age and birth weight.…”

“…The neonatal cAMP lev els may have a role in metabolic adaptation to extrauterine life. Indeed, it is possible that catecholamines and/or glucagon stimulate adenylate cyclase and the cAMP thus formed triggers glycogen breakdown by activating glycogen phosphorylase [3], The finding that neonatal cAMP levels are significantly corre lated with catecholamine concentrations sup ports such an interpretation [7]. Neonatal cAMP may also be involved in fetal lung maturation [11].…”

Modulation of the Blood-Brain Barrier Permeability in Neonatal Cytotoxic Brain Edema: Laboratory and Morphological Findings Obtained on Newborn Piglets with Experimental Pneumothorax

“…The rise of MABP may be indicative of such an effect of vasopressin. In the interpre tation of changes found in the water perme ability and pinocytosis of brain micro vessels, the possible involvement of other vasoactive substances, such as histamine [13,14] and norepinephrine [42] as well as the cyclic AMP and cyclic GMP [8,27,28] should also be taken into consideration. The fact that potassium content did not change signifi cantly in hypoxic-hypercapnic conditions shows the high resistance and different meta bolic rate of neurons in the newborn piglets [2,19,54].…”

Age-Dependent Effects of β₂-Adrenergic-Stimulating Drugs on Fetal Rabbit Lung Liquid and Adrenal Catecholamines

“…One important endogenous mechanism influencing FLL secretion and absorption is obviously the sympathetic nervous system [21] which increases markedly in activity during labor and parturition [3,13]. As men tioned previously (see Introduction) (3-adrenergic mechanisms seem to be of spe cific importance.…”