Effect of des-Tyr1-gamma-endorphin on serotonin metabolism in rat brain regions

Intracerebroventricular (i.c.v.) administration of des-Tyr1-gamma-endorphin (0.1 and 1.0 microgram) caused a decrease of the serotonin (5-HT) concentration of the hippocampus. The concentration of 5-HIAA and the pargyline-induced alterations in 5-HT and 5-HIAA were not affected. No effects were noticed in other brain regions.     

Studies on the modulation of the desensitization of the pituitary gland by luteinizing hormone-releasing hormone in the ovariectomized rat

In ovariectomized rats the desensitization of the LH cells in vivo, which develops during constant rate infusion of LHRH, 1) does not depend on a concomitant depletion of the pituitary LH stores, 2) proceeds normally when the hypothalamo-pituitary connection has been severed and 3) is a process in which LH itself is not involved.     

Changes in plasma levels of metabolites during long-term fasting in the goose]

In fed geese, plasma levels of glucose and alanine were 1.9 g.l-1 and 560 mumol.l-1, respectively. During a long fast (40 days), plasma glucose and alanine were maintained at a high level (1.5-1.8 g.l-1 and 370-540 mumol.l-1, respectively). Plasma level of acetoacetate was very low (40 mumol.l-1); by contrast, plasma level of beta hydroxybutyrate reached very high values (20 mmol.l-1) after about 20 days of fasting, then it decreased. Plasma levels of lactate and pyruvate decreased along the course of the fast, from 2 500 to 2 000 mumol.l-1 and 220 to 170 mumol.l-1, respectively.     

Demonstration of exocytosis in the sinus gland of Astacus Leptodactylus (Nordmann) under the influence of serotonin injections]

Following a serotonin injection, a rise of exocytosis in the sinus gland of the crayfish Astacus leptodactylus is observed together with an increase of the glucose level in the hemolymph. The phenomenon of exocytosis reaches a peak between 2 and 4 h after injection, wheras the highest glucose level in the hemolymph appears between 4 and 6 h after the same injection.     

Immunofluorescent localization of the types of collagen synthesized in the embryonic mouse tooth germ]

The different types of collagen synthesized by embryonic Mouse tooth germs were analysed using an immunohistiological method. The tooth germs were shown to synthesize at least three genetically distinct collagen types: I, III and IV.     

Sequence of cDNA encoding human insulin-like growth factor I precursor

Somatomedins (SM) or insulin-like growth factors (IGF) constitute a heterogeneous group of peptides with important growth-promoting effects in vitro as well as in vivo. Amino acid sequences have been determined for only two of them, IGF-I and IGF-II, which are highly homologous. IGF-I, which is identical with SM-C, is composed of 70 amino acid residues and IGF-II contains 73 amino acids and may be identical with SM-A. Other peptides with different charge properties but with similar SM-like or insulin-like behaviour in biological and receptor assays, have been described but have not yet been fully characterized. The liver is known to be a major site of production of these peptides, but many other tissues--especially in the fetus--may synthesize them as well. We report here the nucleotide sequence of a human liver cDNA encoding the complete amino acid sequence of IGF-I. The IGF-I coding region is flanked by sequences encoding an amino-terminal peptide of at least 25 amino acid residues and a carboxyl-terminal peptide of 35 amino acids. This provides evidence that IGF-I is synthesized as a precursor protein and that formation of IGF-I from this precursor requires proteolytic processing at both ends.