The importance of cardiac glycogen for the maintenance of life in foetal lambs and new‐born animals during anoxia

Accumulation and disappearance of lactate in a fetus with a hemochorial placenta. The role of placental transfer and fetal metabolism.

“…The rate of lactate concen- tration increase reached a maximum value of about 0/7 μπιο1/(πύ -min) when the fetal arterial oxygen concentration was virtually zero. The maximum speed of lactate concentration increase found in this study is about the same s reported for the lamb near term [2] but higher than found for the human fetus of the 5.-6. month (0.3 μπιοί/ (ml · min) according to [9]). The mean lactate concentration in the fetal body was found to be about 60% of the plasma concentration in the guinea-pig according to measurements in the fetal plasma and the homogenized fetal body (see Fig.…”

Pathogenesis of hypoxic-ischemic brain injury

“…38 Noncirculatory factors contributing to neuronal preservation Additional factors considered potentially important in preserving neuronal integrity with asphyxia include biologic alterations that are maturation dependent. Some examples include: (1) decreasing rate of brain metabolism during early development that results in a slower depletion of high-energy compounds during hypoxiaischemia in the fetus as compared with the term infant or adult; 39,40 (2) the use of alternate energy substrate, the neonatal brain having the capacity to use lactate and ketone bodies for energy production; 41,42 (3) the relative resistance of the fetal and neonatal myocardium to hypoxia ischemia; 43,44 and (4) the potential protective role of fetal hemoglobin, that is, it has been calculated that if the PO 2 were to decrease to below a value of approximately 3 torr, and if the venous PO 2 were to decrease to 10 torr (a value that may be found in the cerebral venous blood with asphyxia), the infant would have more oxygen available for brain uptake with a fetal rather than with an adult dissociation curve. 45 Recent data suggest a potential important role for ischemic preconditioning.…”

Low Dietary Zinc Intake During Pregnancy and Lactation of Gilts. Ii. Effects on the Offspring

“…(Patten 1948 Several facts point to intrapartum asphyxia as the cause of death: the animals born dead did not exhibit external anomalies; most of the stillborn piglets were delivered preceded by a prolonged interval (Randall 1972). Some stillborn piglets did not show signs of respiration, but the heart was still beating slowly and weakly for a short period after delivery (Dawkins 1966;Randail 1972); tlrc higher plasma lactic acid (Dawes et al 1959;Randall and Penny 1968) and plasma glucose in born-alive littermates from low-Zn dams (Randall 1979) was comparable to control animals.…”

“…This, in turn, is linked with the ability to maintain an effective circulation and to mobilize glucose from glycogen stores, mainly in the liver and heart (Dawes et al 1959). …”