Differential displacement of cells from the median eminence into the arcuate nucleus during puberty. Effects of melatonin administration

Summary A displacement of catecholaminergic-positive and catalase-containing cells from the median eminence into the arcuate nucleus at puberty has been described previously. This study reports on the displacement phenomena after postnatal administration of melatonin. Catalase-positive cells undergo a delayed displacement from the median eminence into the arcuate nucleus. However, part of this cell population lags behind within the median eminence. This differential reaction of cell displacement by catalase-positive cells is considered as a special reaction of these cells to melatonin administration.     

Effects of chronic lithium administration on concanavalin A binding to plasma membranes from the corpus striatum of rat brain.

The effects of chronic in vivo lithium administration on mannose-containing components of plasma membranes from rat corpus striatum were examined by a 3H-concanavalin A binding displacement method. No difference on Con A binding was observed between sodium or lithium-treated rats during a 1-month period.     

Increased assembly of cytoskeletal proteins associated with the transformation of human liver cells into fibroblast-like cells.

A topoisomerase II inhibitor, novobiocin, and a deacetylase inhibitor, butyrate, synergistically transformed human liver cells into fibroblast-like cells. This morphological change was associated with an increased production of procollagen type III peptide and a simultaneous assembly of actin, tubulin, vimentin and cytokeratin. Novobiocin and butyrate had no marked effect on the phosphorylation state of cytokeratin proteins, but synergistically enhanced [3H]acetate uptake. From these results, it can be speculated that protein acetylation plays an important role in inducing the assembly of cytoskeletal proteins and the morphological transformation of human liver cells.     

Autoradiographic study of the penetration of non-histone chromatin proteins into differentiating cells.

Attention has previously been drawn to a specific effect of NHCP on embryonic Pleurodeles cell differentiation. With a modified NHCP labelling technique, autoradiography has revealed a cytoplasmic concentration of labelled NHCP and has not revealed any difference between homospecific and heterospecific NHCP penetration.     

Effects of dibutyryl cyclic AMP on cultured brain cells from chick embryos of different ages.

The effect of dibutyryl cyclic AMP on cultivated astroblasts from 8-, 12- and 15-day-old chick embryo brain has been studied. The results show that these cells must have reached some degree of maturation in ovo to become morphologically differentiated by the cyclic nucleotide.     

Migration of the chick primordial germ cells from the intracoelomically transplanted germinal crescent into the genital ridge

Résumé Lorsque le croissant germinal est introduit in ovo dans la cavité coelomique de la région gonadique, les cellules germinales primordiales peuvent sortir du greffon et émigrer vers l'épithélium germinatif.     

An uptake of fluorescein isothiocyanate labeled neocarzinostatin into the cancer and normal cells.

An uptake of fluorescein isothiocyanate labeled neocarzinostatin into normal and cancerous epithelial cells from bladder was investigated. Results showed that neocarzinostatin traversed the cell membrane into cytosol and nuclei, and it appeared to have a preferential cytotoxicity for the cancer cell.     

Effects of chronic lithium administration on concanavalin A binding to plasma membranes from the corpus striatum of rat brain

Summary The effects of chronic in vivo lithium administration on mannose-containing components of plasma membranes from rat corpus striatum were examined by a³H-concanavalin A binding displacement method. No difference in Con A binding was observed between sodium or lithium-treated rats during a 1-month period.We thank Dr S. Gershon of this research unit for his encouragement and support during these studies.     

Effects of glucagon and insulin on the Paneth cells of the mouse duodenum.

The effect of glucagon and insulin on the paneth cells (PC) of the duodenum of the mouse was investigated using light microscopy. Both glucagon and insulin were able to increase significantly the number of the secretory granules of PC. This possibly means that these hormones are capable of inhibiting the secretion of PC.     

Effects of stress and adrenocorticotrophin administration on plasma corticosterone levels at different stages of pregnancy in the mouse.

Stress or administration of ACTH to pregnant mice gave rise to much higher plasma corticosterone levels in the second half of pregnancy than in the first half, suggesting that there may be increased adrenal sensitivity to ACTH or decreased metabolism of corticosterone during the second half of pregnancy.     

The male reproductive system of the spruce budworm,Choristoneura fumiferana. 3. Incorporation into seminal components of leucine released during apolysis

Résumé Durant l'apolyse de la nymphe deChoristoneura fumiferana la leucine radio-active, qui faisait corps avec la proteine, est mise en liberté. L'amino-acide libre s'y infiltre dans les composants séminaux tels que le spermatophore, la semence et autres. On recommande l'uridine radio-active pour détecter la semence seule.     

Sertoli cells of adult rats in vitro. III. Purification of androgen-binding protein from the culture medium

Summary A method giving a high yield for the isolation and purification of the androgen-binding protein (ABP) from the nutritional medium of cultured Sertoli cells from adult rats is described.This work was supported by grants No. 80.01547.96 and No.80.01582.96 from the Consiglio Nazionale delle Ricerche.