Energy-dependent translocation of amino-phospholipids in the erythrocyte membrane

In this review, we show how the stability of the asymmetric transverse distribution of phospholipids and the physiological role of the asymmetric distribution can be explained. Experiments with paramagnetic or fluorescent lipids enabled us to show that in fresh red blood cells, i.e. containing ATP, and in resealed ghosts containing ATP (1 mM) the amino derivatives (phosphatidylserine and phosphatidylethanolamine) are selectively transported from the outer monolayer to the inner monolayer of the membranes. On the other hand, phosphatidylcholine and sphingomyelin are not carried and diffuse spontaneously with a very long characteristic time. The ATP-dependent carrier mechanism can be inhibited by protein reacting groups (N-ethyl maleimide and ortho-vanadate), which very probably implies a transmembrane protein specific for amino phospholipids. The affinity for phosphatidylserine seems slightly higher than that for phosphatidylethanolamine. In addition we show the close parallel between the transverse distribution of phospholipids and cell shape. This leads us to suggest that the phospholipid translocation would be used to maintain the natural discoid shape of red blood cells. A possible generalisation of this mechanism to other cells and its implications for endocytosis are discussed.     

Reduced peroxisomal import triggers peroxisomal retrograde signaling

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PI5P4Ks drive metabolic homeostasis through peroxisome-mitochondria interplay

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Immunocytochemical localization of alpha-melanotropin in bovine placenta

The immunocytochemical study of the bovine placenta has demonstrated the presence of cells containing alphamelanotropic hormones, in the decidual epithelium, since the 4th month of pregnancy. The number and the staining intensity of those cells grow up with the placental development. Since the 6th month, we observed the immunoreactional presence of cells in the foetal chorionic epithelium.     

The impact of fetal gender on prematurity in dichorionic twin gestations after in vitro fertilization

Background  

Impact of fetal gender on prematurity has been primarily investigated in singleton pregnancies. In an attempt to understand better how fetal gender may affect gestational length in twin gestations after in vitro fertilization, same-sex twins and opposite twins were compared for pregnancy duration.     

Human ontogeny of the hypothalamic neuroglandular system immunoreactive to an anti-hpGRF 44 immune serum

An hypothalamo-infundibular neuroglandular system stained by an anti-hpGRF 44 serum is described in human brain. Perikarya are located in the infundibular nucleus, and their fibres end in posterior and lateral territories of the zona externa of the Median Eminence . Somatostatin fibres, morphologically different, also end in the same areas. Fibres giving intra- eminential terminals, so as hypothalamic perikarya are revealed as early as the 18 th week of fetal life.