Brain cholesterol in representatives of different vertebrate classes

Studies have been made on the cholesterol content of the brain in 73 species of vertebrates. Cholesterol content increases in both aquatic and terrestrial animals in evolutionary row. Significant variations in cholesterol content were noted within the same class. Comparative studies revealed correlation between changes in phospholipids and cholesterol on one hand and various glycolipids on the other. It is suggested that cholesterol content of the brain in vertebrates depends on ecological factors rather than on taxonomic position of animals.     

Comparative anatomical study of the synovial membrane in representatives of 4 classes of terrestrial vertebrate

The synovial membrane (SM) of some representatives of four terrestrial vertebrate classes was studied by means of scanning electron microscope (SEM). The figures of SM of the mammals (man, mini-pig), birds (fowl, Gallus domesticus L.), reptiles (lizard, Lacerta viridis Laur. and turtle, Testudo graeca L.) and amphibians (frog, Rana esculanta L.) are documented. The SM of all animal species investigated presents a great locally variable appearance in form and surface arrangement of the living cells. The surface of synoviocytes is mostly very rough, forked, the cells having a plenty of wart-like, spiny-like or leaf-like microvilli, with cytoplasmic projections protruding from cell bodies. The largest possible functional surface of SM in mammals is formed by multiple villi and folds, whereas in other animal classes--by a specific arrangement of the lining cells. Locally variable appearance of synoviocytes from human and rabbit joints was described by Date (1979); we have documented the same in birds, reptiles and amphibians, as well. Three characteristic types of locally variable appearance of the surface lining cells were picked out in representatives of the every animal class cited. These cells correspond to the histological types, classified by Key. Beside these basic types, a number of transitory cells appear, that increase the diversity of the appearance of the lining cells in different regions of the SM. We may conclude that all the synoviocytes present the largest possible functional surface, although their external form differs. Their cytoplasm contains all sorts of organelles necessary for synthesis and secretion of mucopolysaccharides of the synovial liquid, as well as for the resorption and phagocytosis.     

Structural organization of nephrons in the kideny and proximal reabsorption in representatives of different vertebrate classes (according to microdissection and micropuncture studies)]

By microdissection method, single nephrons have been isolated from the river lamprey Lampetra fluviatilis, teleost fish Myoxocephalus scorpius (White sea), frog Rana temporaria, lizard Agama caucasica, hen Gallus domesticus and albino rat Rattus norvegicus (Wistar strain). Tubular reabsorptive capacity was measured in kidneys of lampreys and rats by the split oil droplet method. In the animals studied, each of the nephrons consists of the glomerulus, proximal, thin and distal segments. Relative length of the proximal segment does not depend on phylogenetic position of a species. Transtubular isotonic water reabsorption from the proximal tubule in rats is significantly higher than in lampreys. The level of proximal reabsorption is not related to the length of the proximal tubule in the Verterbrates studied but depends on the intensity of tubular transport. The structure which is similar to Henle's loop is present already in Cyclostomes [12]. Further stage of the progressive development of the uriniferous tubules is presented by uneven localization of nephron populations within the kideney in Reptiles. These data suggest that the effective system of osmotic concentration appeared in evolution not as the result of Henle's loop formation, but on the basis of the development of the medullar substance formed mainly by intercortical and juxtamedullar nephron populations.     

The stemline chromosomes of three cell lines representing different vertebrate classes

The chromosomes of the stemlines were analyzed in three cell lines stored in the Cell Bank of the South Jersey Medical Research Foundation, Camden, N. J. The cell lines were of marsupial, amphibian and teleostean origin, and 10 to 25 complete chromosome analyses in each of them formed the basis for idiograms. In the marsupial and the frog, comparison could be made with the normal karyotype of the species.Dedicated to Professor J. Seiler on the occasion of his 80th birthday.     

Sperm antigenicity shared in five vertebrate classes

The antigens of spermatozoa are of special interest because of their involvement in immunoinfertility and because they are candidate targets for immunocontraception. Conserved sperm epitopes from divergent species may present a suitable source and an animal model for the investigation of the above factors. We compared spermatozoa from six species of vertebrates belonging to five different classes, in order to demonstrate the existence of shared antigens. We used whole fixed male germ cells from trout, frog, turtle, rooster, rabbit and human in the enzyme-linked immunosorbent assay with rabbit polyclonal sperm-specific antisera. After absorption of the antisera with non-gametic (liver powder) and gametic tissue preparations, we established significant cross-reactions among the spermatozoa of all tested species. The antigenic similarities were the strongest between spermatozoa of trout and frog, trout and human, rabbit and turtle, rabbit and rooster. These data demonstrate the existence of highly conserved epitopes in spermatozoa from divergent vertebrate species belonging to different animal classes, in contrast to structures of the female gametes (zona pellucida) for which antigenicity was found to be limited to the animal class.     

Frequency and biodiversity of symbionts in representatives of the main classes of Ciliophora

Representatives of all classes of Ciliophora have been studied for the detection and investigation of both prokaryotic and eukaryotic (not algal) endo- (EnS) and ectosymbionts (EcS). Different methods including transmission electron microscopy (TEM) and fluorescence in situ hybridisation (FISH) have been used. Apparently, the capability of keeping symbionts varies among the different ciliate groups as it generally is the case in different protist taxa. Most of the prokaryotic EnSs detected belong to Alphaproteobacteria. Holospora or Holospora-like infectious bacteria of this group were found in representatives of Heterotrichea, Armophorea, Phyllopharyngea, Prostomatea and mainly of Oligohymenophorea. Bacteria associated with bacteriophages were found in species of Heterotrichea and Oligohymenophorea. This holds true also for bacteria with R-bodies. A quite rare type of EnS - motile bacteria - was found in ciliates of the same two classes as well, either in the cytoplasm (Heterotrichea) or in the macronucleus and its perinuclear space (Oligohymenophorea). EcSs are more common in Heterotrichea, Armophorea and Plagiopylea, but were never found in other groups. Among the eukaryotic EnSs of ciliates, very few representatives of Microsporidia and Trypanosomatidae were recorded. In conclusion, heterotrichs and oligohymenophoreans are the most promising groups of Ciliophora for the investigation of symbiosis.     

Brain proteolipids. Isolation, purification and effect on ionic permeability of membranes

Proteolipid apoproteins have been isolated from a whole bovine brain homogenate by chloroform/methanol extraction, and fractionated by chromatography on modified (lipophilic) Sephadex, followed by ion-exchange chromatography on CM-Trisacryl. The various final, highly hydrophobic, fractions are homogeneous (sodium dodecyl sulfate/polyacrylamide gel electrophoresis). Transmembrane ion transfers were studied by 22Na + flux and electrical conductance measurements. Single channel events were observed at low protein concentrations, in particular with one of the final homogeneous apoproteolipids of molecular mass 24 kDa.     

An electrophoretic analysis of proteolipids from different rat brain subcellular fractions

Proteolipid proteins were extracted from adult rat brain subcellular fractions and purified by chromatography on Sephadex LH-60. Polyacrylamide gel electrophoresis of the delipidized proteins, in the presence or absence of 8 M urea, was carried out with all fractions. The distribution of the various types of proteolipid proteins was studied and their molecular weight calculated by the Ferguson relationship. Several bands of proteolipid proteins were found in the five membrane fractions analyzed. Some of them, such as the 17.5 K and 37 K components were very prominent in mitochondria and synaptosomes. The 30 K component was found in myelin-derived membranes and in microsomes, while the 20 K and 25 K proteolipid proteins were present in all subcellular fractions. The 30 K component (proteolipid protein (PLP)), typical of the purified myelin membranes, showed a similar distribution to that of 2′,3′-cyclic-nucleotide 3′-phosphohydrolase (EC 3.1.4.37) activity, while the other major proteolipid protein present in all subcellular fractions (25 K) did not show such parallelism, indicating that it might not be an exclusive component of myelin. The electrophoretic pattern of microsomal proteolipid proteins did not show the high molecular weight components (aggregates of PLP) which are found in myelin. Furthermore, the 30 K component showed a smaller $\text{Y}{}_0$ value than that of the 30 K found in myelin. Thus the presence of 30 K proteolipid protein in microsomes should not be considered as being due to myelin contamination.     

Lactase polymorphism in representatives of different ethnic-territorial groups]

Lactase polymorphism was studied in the native population of West Siberia and also in Buryatia. LAC*R frequency observed is-Khants- 0.8367, Mansi - 0.8660, Nenets - 0.8944, Buryats - 0.6883. The data obtained are considered to be the result of natural selection under traditional historical economical-cultural environment of the ethnic groups in question.     

Distribution of immunoreactive Tamm-Horsfall protein in various species in the vertebrate classes

A sheep antibody to human Tamm-Horsfall protein, the major protein in normal urine, was used in an immunohistological study of organs of 48 species of vertebrate animals, representing the classes Mammalia, Aves, Reptilia, Amphibia, Osteichthyes and Chondrichthyes. Immunoreacvity was shown in the thick limb of the loop of Henle in the kidney of mammals, but there was no reactivity with tissues of birds or reptiles. Superficial layers of the skin of several amphibians and fish, superficial layers of the oral mucosa and gills of fish, and the distal tubules of the kidney of some amphibians, reacted with the antibody. Immunoreactivity with mammalian kidney was removed by passage of the antibody down an immunoadsorption column coated with human Tamm-Horsfall protein, and amphibian immunoreactivity was removed by incubation of the antibody with material prepared from frogs in the same way as Tamm-Horsfall protein. These findings suggest that immunoreactive Tamm-Horsfall protein appeared early in vertebrate phylogeny, initially in skin and gills and later in kidney, and that although conserved in evolution, it shows antigenic differences between amphibians and mammals. Its distribution is consistent with the hypothesis that it acts as a waterproofing agent.     

Glycogen content and activities of phosphorylase and glucose-6-phosphatase in the fast and slow muscles of representatives of different classes of vertebrates

Studies have been made on glycogen content as well as on the activity of phosphorylase and glucose-6-phosphatase in fast and slow muscles from representatives of 6 classes of vertebrates (Lampetra fluviatilis, Cyprinus carpio, Rana temporaria, Rana ridibunda, Emys orbicularis, hen, rat). Glycogen level and glucose-6-phosphatase activity are either higher in slow muscles, or practically identical in both types of muscles (glucose-6-phosphatase is absent from the fast muscles of hens and rats). On the contrary, phosphorylase activity is higher in fast muscles, this finding being true only for higher vertebrates and lampreys.     

The mechanism of the intranasal action of dermorphin in representatives of 2 classes of vertebrates]

It has been shown that endogenous opioid dermorphin induces effective analgesia after intranasal injection to fish (0.02-0.20 mg/kg) and rats (0.005 mg/kg). Maintenance of dermorphin analgesia after olfactory and trigeminal denervation indicates that the analgetic effect is not realized via the olfactory receptors or free terminals of the trigeminal nerve.