Jean Ginsburg

Comparison of pentazocine and pethidine in normal labor

Abstract A double blind trial of the effects of pentazocine and pethidine in labor in 200 women has shown that the analgesic effect of the two drugs is similar. The level of analgesic drug in cord blood was comparatively higher after pethidine. The Apgar score at one minute was better in infants of mothers not given analgesia. Both drugs caused peripheral vasodilatation and slowed respiratory rate.

Effect of epinephrine on placental carbohydrate metabolism

Abstract The rate of glycogen utilization, lactic acid production, and glucose uptake and the effect of in vitro epinephrine on these processes were determined in normal human placentas. Epinephrine increased placental lactic acid production and glycogen breakdown in both bicarbonate and phosphate buffers; glucose uptake was increased only in bicarbonate buffer. Different metabolic patterns were produced during incubation in anoxic conditions. The results show that placental, glycogen is not the sole source of the lactic acid produced during incubation or of the excess lactate released under the influence of epinephrine and they provide evidence that the human placenta has its own specific metabolic pattern and is not the biochemical equivalent of the liver.

Effect of adrenaline on human placental lactate production in vitro

Abstract 1. 1. The in vitro effect of adrenaline upon human placental metabolism has been studied in fresh slices of placental tissue at different stages of gestation. 2. 2. The hormone increased placental lactate production by approximately the same amount in early and term placentas. 3. 3. Adrenaline effect was reduced in two placentas associated with intrauterine death. 4. 4. It is concluded that in the present experimental conditions metabolic responses in the human placenta resemble those in skeletal muscle more than liver.

SOME ASPECTS OF PLACENTAL CARBOHYDRATE METABOLISM IN HUMAN DIABETES

THE higher birth-weight and perinatal mortality of babies born to diabetic women, despite good diabetic control, has frequently been attributed to a metabolic defect. The possibility that a metabolic disturbance might be present in the placenta in such cases is indicated by the raised placental glycogen content in women with diabetes (Heijkenskjold and Cemzell, 1957). Tissue studies in rats have also provided evidence of altered placental carbohydrate metabolism in alloxan-induced diabetes (Hagerman, 1962). The present study was designed to investigate some aspects of human placental carbohydrate metabolism in diabetes, in particular, lactate production, glucose uptake and glycogen breakdown in vitro, and the effect of adrenaline on these processes.

Glucose Metabolism via the Pentose Phosphate Pathway Relative to Nucleic Acid and Protein Synthesis in the Human Placenta

A parallelism has been demonstrated between the extent of glucose metabolism via the pentose phosphate pathway and the biosynthesis of nucleic acids in the human placenta during gestation.

Arteriolar distensibility in hypertensive pregnancy

In order to investigate further the mechanism of the increased resistance in hypertensive pregnancy, a study was made of the ability of forearm vessels to dilate in hypertensive and normotensive pregnancy. Arteriolar response to arterial occlusion and local exercise was studied, by a plethysmographic technique, in 31 normotensive pregnant women and in 39 with either essential hypertension or toxemia of pregnancy. In normotensitive women, the response was unchanged throughout pregnancy and the puerperium. In both toxemia and essential hypertension in pregnancy, there was an increase in peripheral vascular resistance at both resting and peak levels of blood flow. In essential hypertension there was also a slight increase in peak flow. It is concluded that the vessel wall itself may be abnormal in hypertensive pregnancy.

Placental lactate production in toxemia of pregnancy

Lactic acid production was measured in vitro in placentas from women with essential hypertension or who developed toxemia of pregnancy. Placental lactate production was increased compared with normal in severe toxemia but not in cases of mild toxemia or essential hypertension. However, the effect of epinephrine on lactic acid production was not increased in toxemic placentas. The excess production demonstrated in severe toxemia may be related to placental anoxia but could also result from a shift in metabolic pathways in this condition.

Some aspects of placental carbohydrate metabolism in the rat

Abstract Lactic acid production, glucose uptake and glycogen utilization were measured in term rat placentae in vitro in aerobic and anaerobic conditions. The addition of adrenaline to the incubation media had no influence on these parameters. The findings contrast with the results of similar studies in human placentae and in other tissues of the rat. It is suggested that the difference in response between rat and human placentae casts doubts on the validity of using rodents for the assessment of potential drug effects in pregnant women.

Patterns of hormone excretion in abnormal pregnancy

Serial assays of urinary estrone, estradiol, estriol, pregnanediol, and HCG have been performed during pregnancy and the puerperium in 3 patients with essential hypertension, 2 pregnant diabetic patients, one subject with pre-eclamptic toxemia, and one with placental insufficiency. Considerable day-to-day fluctuations in steroid and HCG excretion were noted in all cases, again emphasizing the necessity for conducting serial rather than isolated determinations in such investigations. Values for urinary estriol were abnormally low for the appropriate stage of pregnancy in 4 subjects. In 5 a marked fall in estriol output occurred some days prior to delivery either by cesarean section or by the vaginal route. The ratio, pregnanediol/estriol, tended to be higher in abnormal than in normal pregnancy, and the pattern of values for the ratio throughout the gestation period differed in the two groups. In 4 patients a marked fall in the ratio to figures approaching normality was noted in the weeks immediately prior to delivery.

Metabolism of the normal cardiovascular wall. IV. Effect of epinephrine and isopropylnorepinephrine.

* Charing Cross Hospital Medical School, London, W.C.2, and Royal Free Hospital Medical School, London, W.C.1. A relation between some of the vascular effects of the sympathomimetic amines and their influence on carbohydrate metabolism has been postulated and the liberation of lactic acid by stimulation of glycolysis has been regarded as of particular importance in this respect 2 However, although there is undoubted evidence that epinephrine releases lactic acid from skeletal muscle both in vivo3 and in vitro,4 the participation of vascular smooth muscle in this response has not been established. The present paper reports the results of a study of the in vivo effects of epinephrine and isopropylnorepinephrine on systemic lactate, pyruvate, and glucose production, and the in vitro action of these amines on the glucose metabolism of arterial smooth muscle in the dog.