Alterations in high-affinity binding characteristics and levels of opioids in invertebrate ganglia during aging: Evidence for an opioid compensatory mechanism

In Mytilus and Leucophaea the high-affinity binding site density is significantly lower in old animals than in young animals, whereas the low-affinity site density remains unchanged. In Mytilus the estimated met-enkephalin and met-enkephalin-Arg6-Phe7 levels are significantly higher in old than in young animals. In Leucophaea only the met-enkephalin level can be determined, and it is also higher in old animals. The decrease in the high-affinity binding site density and the corresponding increase in endogenous enkephalin levels suggest the existence of an opioid compensatory mechanism associated with the aging process. In Mytilus there is a demonstrated decrease with age in intraganglionic dopamine levels in response to applied opiates. In addition, the inhibition of dopamine-stimulated adenylate cyclase activity by opiates also decreases in older animals. In Leucophaea the sex difference in opioid binding densities diminishes with age.     

Isoelectric point determination of human and camel beta-endorphin, alpha-endorphin and enkephalins

The isoelectric point of the camel and the human β-endorphin, of the α-endorphin and the enkephalins were determined by analytical isoelectric focusing on 1 mm thin polyacrylamide gel slab. The difficulty of staining peptides as short as β-endorphin or smaller was overcomed using a modification of Bibring and Baxandall's or Faupel and Von Arx's staining method. The camel β-endorphin gives two bands having isoelectric point of 10.3 and 10.4, the human β-endorphin focus at pH 9.9, while α-endorphin, leu and met-enkephalin at pH 5.9, 5.5 and 5.45 respectively. The staining method described coupled with the isoelectric focusing seems to be fit for discriminating β-endorphin in a crude rat pituitary extract.     

LIPID COMPOSITION OF THE CENTRAL NERVOUS SYSTEM OF MARINE VERTEBRATES

—The lipid composition of the central nervous system of some marine vertebrates and two mammalian species (rat and man) was analysed by one- and two-dimensional quantitative thin-layer chromatography, and the cerebroside fatty acids were analysed by gas chromatography. The concentrations of sphingomyelin and cerebrosides are higher in mammals than in fishes, while no significant differences are observed for other lipid classes. Furthermore, in mammals the ratio between hydroxy and normal fatty acids in the cerebrosides is much higher than in fishes. The cerebrosides of mammals contain more very long chain fatty acids than those of marine vertebrates.     

Genetic structure of the population of Sicily.

Genetic heterogeneity within Sicily was investigated on the basis of ACP1, ADA, ESD, GLO1, PGD, PGM1, PGM2, SODA, ABO, and MN gene frequencies, and compared to those of other regions of Italy for which these same loci have been examined. Correspondence analysis revealed no differences within the island, at least at the provincial level, but showed genetic differentiation among Italian regions, distinctly clustering northern, central, and southern populations, respectively. These data indicate a close relationship between Sicily and southern Italy. In addition, the contribution of Middle Eastern populations to the gene pool of Sicily was evident.