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At least 19 recordsLinked to original sources
PubMed1977

Comparison of the cross-linking patterns of lamprey fibrinogen and fibrin by the action of the intrinsic lamprey factor XIII and human factor XIII during the process of blood coagulation.

Intrinsic lamprey factor XIII cross-links the gamma chain of lamprey fibrin (50,000 daltons) to the gamma-dimer (100,000 daltons). The alpha-chain (110,000 daltons) is cross-linked very slowly to alpha-dimer (210,000 daltons) and alpha-trimer (330,000 daltons). In contrast, human factor XIII, when added in combination with intrinsic lamprey factor XIII, cross-links the alpha-chain of lamprey fibrin to a high molecular weight polymer, and any remaining gamma-chain is also cross-linked to a polymer. However, the gamma-chain that has previously cross-linked to the gamma-dimer by the intrinsic lamprey factor XIII remains as a gamma-dimer. Factor XIII-free lamprey fibrin cross-links all its subunits (alpha, beta, gamma) to high molecular weight polymers when human factor XIII is added. In contrast to human and bovine fibrin where alpha-chain cross-linking in the process of blood coagulation commences when all of the gamma-chain has cross-linked, the lamprey alpha-chain will begin to cross-link when approximately half of the gamma-chain has cross-linked to the gamma-dimer.

Animals↗
PubMed1976

The haematopoietic supraneural organ of adult, sexually immature river lampreys (Lampetra fluviatilis [L.] Gray) with particular reference to azurophil leucocytes.

The haematopoietic tissue in the supraneural organ of the freshwater river lamprey (Lampetra fluviatilis L. Gray) was studied in sexually immature animals. Besides erythro- and granulopoietic elements, macrophages, reticular cells, fibroblasts and glycogen-rich fat cells were seen. Developing granulocytes of the lamprey contain one type of azurophil granules originating from small cytoplasmic (Golgi) vesicles. The lamprey's azurophil granulocytes seem to be homologous with those of fishes. However, the granulocytes of fishes, studied thus far, show granules with only one type of inclusion, whereas in lamprey the granulocyte inclusions are variable in size and shape. Thus, lamprey granulocytes are, in this respect, reminiscent of similar cells of higher vertebrates. The PAS and alkaline phosphatase reactions, common markers of vertebrate neutrophil leucocytes, are very weak in the haematopoietic tissue granulocytes of the lamprey, and intense in the blood cells of the same animal. Lamprey granulocytes, similarly to the granulocytes of Chondrostei and Elasmobranchiata, do not stain with peroxidase, naphthol-AS-D-chloroacetate esterase and sudan black B. The haematopoietic tissue contains a relatively high number of degenerated granulocytes.

Animals↗
PubMed1979

Comparative study of the monoamine neuron system in the spinal cord of the lamprey and hagfish.

Spinal cords of the lamprey and hagfish were fluorescence histochemically and electron microscopically examined. Ventrally to the central canal of both cyclostomes, yellow fluorescence bound to small to medium sized neurons was observed. In the lamprey only, weakly blue-green fluorescent subependymal cells were seen just beneath the central canal. In the ventral floor of their spinal cord, yellow fluorescent varicosities were observed; their density was much higher in the lamprey than in the hagfish. The lateral surface of the hagfish spinal cord was marginated by a chain of yellow fluorescent varicosities. The yellow fluorescence was microspectrofluorometrically identified as fluorescence due to 5-HT. Electron microscopically, the 5-HT neurons contained many large dense-core vesicles. The 5-HT varicosities or terminals seen in the ventral zone of both cyclostomes possessed the large dense-core vesicles and small clear synaptic vesicles, which appeared as small dense-core vesicles after KMnO4 fixation. The terminal of the lamprey was nakedly situated on the ventral surface, while that of the hagfish was always covered by the superficial glial layer. This finding seems to favor the view that lamprey and hagfish should be divided into two different classes.

Animals↗
PubMedDate not supplied

[Composition and structure of the chief gangliosides in the brain of the lamprey Lampetra fluviatilis].

It has been shown that 4-sphingenine is the main sphingoid in lamprey brain gangliosides. Saturated and monoenoic fatty acids were found to predominate, the main fatty acids in the lamprey brain are presented by stearic (43-49% of total fatty acids) and oleic ones. N-acetylneuraminic acid is the only sialic acid found in gangliosides from the lamprey brain. Other components of ganglioside molecules are glucose, galactose and N-acetylgalactosamine. Two main lamprey brain gangliosides which constitute more than 90% of lipid-bound sialic acid, were found to be trisialogangliosides. It was shown that both gangliosides have the following structure in their molecules: (formula see text). They differ in the position of two other sialic acid residues. Data on lamprey brain gangliosides in the literature are practically absent. The data obtained in the present study confirmed the conclusions on changes in the hydrophobic part of ganglioside molecule in evolution of vertebrates and made it possible to define more exactly the molecular evolution of ganglioside carbohydrate component.

Animals↗
PubMed1979

Projections of lamprey spinal neurons determined by the retrograde axonal transport of horseradish peroxidase.

The spinal cords of larval sea lampreys (Petromyzon marinus) and adult river lampreys (Ichthyomyzon unicuspis) were injected with horseradish peroxidase through a transection 1 cm caudal to the last gill. Some animals also had a spinal hemisection 1 cm caudal to the injection. After recovery periods of 1 to 52 days, the spinal cords were treated with diaminobenzidene and hydrogen peroxide, and the projections of various cell types determined in wholemount slides. From these observations the following conclusions were drawn. Most dorsal cells (primary sensory cells) are bipolar with a long rostral projection and a short caudal projection of no more than 5-10 mm. Both processes travel in the ipsilateral dorsal column. Their peripheral processes enter the dorsal roots as branches of their central axons. Some dorsal cells send processes out three or more dorsal roots both rostral and caudal to the cell body. Myotomal motoneurons have characteristic locations in the medial gray column and send prominent transversely oriented dendrites into the lateral columns. A few motoneurons are unusually large. In addition to giant interneurons the majority of smaller rostrally projecting interneurons also have decussating axons. A recently described cell type, the oblique bipolar cell, appears to have an exclusively crossed rostral projection. Although most edge cells project rostrally, as many as 20% may have a caudal projection or both rostral and caudal projections. Edge cells project equally to the ipsilateral and contralateral spinal hemicord, but their processes do not extend more than about 18 mm in sea lamprey larvae and 37 mm in adult river lampreys. Lateral cells project exclusively to the ipsilateral caudal hemicord. A few cells which resemble lateral cells in location and in possessing large lateral dendrites, project rostrally. However, these have atypical morphologic features which probably distinguish them from true lateral cells. Thus far, regardless of cell type, all decussating axons seem to pass ventral to the central canal, while decussating medial dendrites pass dorsally.

Animals↗
PubMedDate not supplied

[Isolation and several properties of the glyceraldehyde-3-phosphate dehydrogenase from the muscles of the lamprey Lampetra fluviatillis].

Procedure for isolation of electrophoretically homogeneous, crystalline glyceraldehyde-3-phosphate dehydrogenase from lamprey muscles is described. Amino acid composition of the enzyme was investigated and compared with that of the same dehydrogenase from other sources. With respect to its secondary structure and kinetic parameters, the lamprey enzyme does not significantly differ from those of other animals. Activation energy for the lamprey enzyme is lower than for the same enzyme from endothermic animasl. "Temperature modulation" of Michaelis constant described in the literature, was not confirmed for the lamprey enzyme in the range of physiological pH values.

Animals↗
PubMedDate not supplied

[Fatty acids of the cerebrosides (1-beta-glycosylceramides) and sulfatides (sulfoglycosylceramides) of the brain of the river lamprey Lampetra fluviatilis].

The analysis of the fatty acids of cerebrosides and sulfatides from the brain of the lamprey L. fluviatilis has been carried out. Only normal fatty acids were revealed by TLC of total methyl esters of the fatty acid of cerebrosides and sulfatides. The hydroxy fatty acids are apparently absent. The composition of the normal fatty acids of cerebrosides and sulfatides is very similar. TLC revealed fatty acids containing from 14 to 27 C mainly saturated and small amount of monoenes. The fatty acid pattern of cerebrosides and sulfatides from lamprey brain resembles that from the brain of other vertebrates. The peculiarity of the fatty acid composition of these glycolipids in the lamprey brain is the high proportion of short chain (C14--C18) saturated acids, especially of palmitic acid. The fatty acid composition of cerebrosides and sulfatides from lamprey brain which does not contain myelin is rather similar to that of mammalian brain in early development before the onset of myelination.

Animals↗
PubMed1977

Retinal projections in larval, transforming and adult sea lamprey, Petromyzon marinus.

Unilateral enucleations were performed on larval, transforming and adult sea lampreys. Following 5 to 11 days survival, the animals were sacrificed and the brains were processed using a modified Fink-Heimer technique. In larvae, contralateral optic projections were found to the posterior one-third of the dorsal thalamus, the pretectum, and the optic tectum. No ipsilateral projections were present in the larvae. In enucleated transforming and adult lampreys, degenerating axons were observed in the optic chiasm and bilaterally in the optic tracts. Retinal efferents projected bilaterally to a lateral neuropil region ("tractus opticus") in the posterior one-half of the dorsal thalamus. Contralaterally, a conspicuous dorsomedial cell group (lateral geniculate nucleus) also received a projection. Contralateral projections to the superficial layers of the pretectum and optic tectum were observed. Ipsilateral retinal projections to the pretectum and optic tectum in transforming and adult lampreys were restricted to a small zone at the ventrolateral margins of the pretectum and tectum. The changes in distribution of retinofugal projections during transformation appear to be occurring at the same time that the eye differentiates into its adult form.

Animals↗
PubMed1978

The reticular formation of lampreys (Petromyzonidae)--a target area for exohypothalamic vasotocinergic fibres.

The octapeptide vasotocin, which is formed in the classical neurosecretory nuclei of lampreys (Petromyzonidae), is transported, bound to the carrier protein neurophysin, not only to the neurohypophysis but also to various other regions of the brain via exohypothalamic fibres. A target area of this exohypothalamic vasotocinergic system is, in the brook lamprey (Lampetra planeri Bloch), a relatively well circumscribed area in the isthmus region of the rhombencephalic tegmentum motoricum, which is called area lateralis tegmenti. In this area, which belongs to the reticular formation, the vasotocinergic fibres form synaptic contacts with nerve cell perikarya and processes. The vesicles contained in the fibres were identified, ultrahistochemically, as neurophysin vesicles. They correspond to the neurophysin vesicles observed in the neurohypophysis of the same species. The functional significance of the vasotocinergic supply to portions of the reticular formation in lampreys is open to discussion.

Animals↗
PubMed1976

Amino acid compositions of the subunit chains of lamprey fibrinogen. Evolutionary significance of some structural anomalies.

Our original objective in studying lamprey fibrinogen was embodied in the notion that the proteins of this ancient vertebrate might themselves by more primitive. As such, it was possible that the subunits of lamprey fibrinogen might have been more similar, one to another, than is the case in higher vertebrates, or even identical. Amino acid analysis of the individual polypeptide chains indicates, however, that the alpha, beta and gamma-chains are instead more dissimilar from each other than are the corresponding chains from human fibrinogen. This finding was somewhat surprising because regions of homology have been detected recently among those three chains when isolated from human fibrinogen, suggesting that all three chains have indeed descended from a common ancestor. The paradox is especially evidenced by the unusual amino acid composition of the lamprey alpha-chain, 45% of which is composed of glycine, serine and threonine. This unusual amino acid distribution may be involved in the anomalous behavior of these chains on sodium dodecyl sulfate polyacrylamide gel electrophoresis.

Amino Acids↗
PubMed2025

Divergence of Leptin Receptor and Interleukin-6 Receptor Subunit b in Early Vertebrate Evolution and Physiological Insights from the Sea Lamprey.

Current knowledge of class-I cytokine receptors comes primarily from studies in jawed vertebrates (gnathostomes), and their origin and evolution remain unresolved. In this study, we identified a leptin receptor-like sequence (LepRL) and three interleukin-6 receptor subunit b-like sequences (IL6RBL) from a jawless vertebrate (cyclostome), the sea lamprey (Petromyzon marinus). Based on structural, phylogenetic, and syntenic analyses, we deduced that these lamprey receptors are likely distinct ohnologs to gnathostome LepR and IL6RB-related receptors, respectively, that arose in the two rounds of vertebrate whole-genome duplication (1R and 2R). Notably, lamprey LepRL likely originated from a different 1R progenitor than the one giving rise to gnathostome LepR during cyclostome hexaploidization. Differential patterns in mRNA expression of LepRL and IL6RBLs were observed among adult tissues, during larval metamorphosis, and in response to juvenile feeding. Feeding stimulated hepatic expression of LepRL and IL6RBL (namely, IL6RBL1) mRNAs in correlation with upregulation of insulin-like growth factor mRNA, whereas brain LepRL and IL6RBL1 mRNA expression was correlated positively with neuropeptide Y but inversely with intestinal content in fed juveniles. Notably, these observations along with immunolocalization of LepRL in the hypothalamus suggest a role of leptin signaling in regulating energy balance that is conserved among vertebrates. Additionally, seawater exposure stimulated branchial LepRL expression coincident with increased expression of ion transporters in ionocytes, indicating a role of leptin signaling in osmoregulation. These findings provide new insight into the early evolution of class-I cytokine receptors and reveal diverse functions of the leptin signaling system in jawless vertebrate.

Animals↗
PubMed1978

Conductance increases produced by glycine and gamma-aminobutyric acid in lamprey interneurones.

1. Conductances of individual neurones in the isolated lamprey spinal cord were measured with separate intracellular electrodes for recording potentials and for passing current pulses during application of glycine or GABA (0.1-1.0 MM) in Ca-free bathing fluid. Large, reversible increases in conductance were produced in giant interneurones by both amino acids, but Müller axons and sensory dorsal cells were unaffected. 2. Conductance increases produced by glycine and by GABA were selective for Cl. Both conductance increases were linearly related to external Cl concentrations and repeated exposure to the amino acids in Cl-free fluid progressively reduced the conductance increases to less than 1% of their values in normal Cl. 3. Strychnine was a competitive antagonist of glycine, while GABA was antagonized competitively by bicuculline and non-competitively by picrotoxin. 4. The sensitivity of giant interneurones to glycine and GABA increased at low temperatures, in Na-free fluid, and after repeated exposure to the amino acids. Sensitization may have been produced by inhibition of uptake mechanisms for glycine and GABA in the spinal cord. 5. Discharges of interneurones recorded extracellularly were inhibited by bath-applied glycine and GABA, but directly elicited action potentials of axons were unaffected. Strychnine and Cl-free fluid in the presence of Ca produced seizures in lamprey spinal cord. 6. The conclusions of these experiments are that different receptors for glycine and for GABA are present on giant interneurones, that glycine is the better candidate for an inhibitory transmitter in the lamprey spinal cord, and that GABA produces effects similar to those which have been well studied in arthropod muscle.

Action Potentials↗
PubMed1978

Measurement of single nephron filtration rate in the kidney of the river lamprey, Lampetra fluviatilis L.

1. The reliability of [3H]inulin as a reference substance for the measurement of glomerular filtration rate (GFR) in river lampreys was investigated. 2. Simultaneously measured renal clearances of [3H]inulin and [14C]-polyethylene glycol (PEG) were not significantly different. 3. Recoveries of [3H]inulin in the urine following its injection into the proximal tubule and urinary duct averaged 83.5+/-4.0% (n = 14) and 93.0+/-4.6% (n = 9) respectively. 4. No evidence was obtained to suggest penetration of the tubular wall by by [3H]inulin following its introduction into peritubular capillaries. 5. Gel-filtration of lamprey plasma and urine produced no signs of any significant degradation of the inulin to fructose. 6. [3H]inulin recoveries, though significantly below 100% (P less than 0.001), were considered adequate to justify its use after allowing for possible sources of error. 7. A mean single nephron filtration rate (SNGFR) value of 7.02+/-0.27 nl/min (n = 89) was obtained from the kidneys of anaesthetized freshwater lampreys. 8. [51 Cr]EDTA was found to be totally unsuitable for the measurement of GFR in this species.

Animals↗
PubMed1976

[Autoradiographic and histochemical study of the intestinal epithelium of the Baltic lamprey].

The intestinal epithelium of the Baltic lamprey and its larva was studied. Glandular cells and absorbing cells simultaneously capable to synthesize polysaccharides were found histochemically in the composition of the epithelial layer. The cranial zone where glandular cells analogous to the cells of the pancreas were concentrated was revealed in the medial intestine of the larva. The rest of the intestine was devoid of specialized glandular cells. Using H3-thymidine as a precursor it was shown that in the cranial zone of the intestine the cambial cells were scattered diffusely throughout the whole epithelial layer and in other portions of the medial intestine the cambial zone was distinctly seen in the lateral portions of the intestine (the area of the fornix) where labelled nuclei were formed and mitoses took place. After injection of H3-thymidine poor incorporation of the isotope was found in the nuclei of solitary cells of some adult lampreys going to spawning. Uneven incorporation of S35-methyonine, used as a precursor, in the epithelium of the intestine and the liver of the adult lamprey was shown.

Animals↗
PubMed1977

Records of Cucullanus truttae (Fabricius, 1794) (Nematoda: Cucullanidae) from Swedish brook lampreys, Lampetra planeri (Bloch).

Adult nematodes of the family Cucullanidae, parasitic in the abdominal cavity of the brook lamprey, Lampetra planeri (Bloch) from the River Stensån, south Sweden are described and illustrated. According to the morphometry, these nematodes belong to the species Cucullanus truttae (Fabricius, 1794)--a common intestinal parasite of salmonid fishes. The name Dacnitis stelmioides Vessichelli, 1910 is considered to be a synonym of the latter. The role of lampreys in the life-cycle of C. truttae is discussed: although lampreys are either intermediate hosts or serve only as transport hosts for larvae of this parasite, the nematode larvae can attain maturity in this host.

Animals↗
PubMed1979

Development of the renal corpuscle during metamorphosis in the lamprey.

The renal corpuscle of the adult lamprey, Petromyzon marinus L., is formed during the programmed period of metamorphosis. Development is initiated early in this metamorphic period and is marked by the synchronous formation and growth of rudimentary nephron units (RNU) from longitudinal cord of nephrogenictissue extending from the posterior tip of the degenerating larval kidney to the cloaca and connected to the peritoneal epithelium. Detachment of the RNU from the peritoneum involves autolysis and cell death and is accompanied by their branching into five or six hexagonally-arranged nephrons which radiate from the original point of attachment. Differentiation of the epithelial cells at the proximal ends of the nephrons is preceded by the widening of lateral intercellular spaces, the formation of tubular lumina (primitive urinary spaces), the loss of apical cell junctions, and the development of a capillary network with its associated mesangium. With the extension of the capillaries and mesangium between the proximal ends of adjacent undifferentiated nephrons, visceral epithelial cells (podocytes), with long cell processes (trabeculae) and slit membranes, make their appearance. The urinary spaces resulting from this form of development are lined by the epithelium of the dilated ends of the nephrons (nephric capsules). The cells of these capsules differentiate mainly into podocytes, but a few parietal cells connect to the draining tubule. This method of development explains the unique form of the renal corpuscle in the adult lamprey. Despite the type of morphogenesis, this renal corpuscle possesses the fine-structural features seen in the renal corpuscles of other vertebrates.

Animals↗
PubMed1979

Fine structure of the liver in the larval lamprey, Petromyzon marinus L.; hepatocytes and sinusoids.

The ultrastructure of hepatocytes, bile canaliculi, and hepatic sinusoids of the larval lamprey, Petromyzon marinus, was examined using thin-sectioned and freeze-fractured tissues. The liver is a "tubular gland" with hepatocytes arranged in a tubular fashion around large bile canaliculi. Hepatocytes are roughly conical in shape, with their tapered apices facing a bile canalicular lumen. They possess extensive rough and smooth endoplasmic reticulum, a well-developed Golgi complex, abundant mitochondria, and varying numbers of large secondary lysosomes. Both secondary lysosomes and the Golgi complex are concentrated in the apical or peribiliary cytoplasm, indicating a possible role in bile secretion. The apical surfaces of the hepatocytes bear numerous elongate microvilli and occasional cilia, which project into the bile canaliculi. The hepatocytes are joined, apically, by junctional complexes composed of zonulae occludentes and adhaerentes. In freeze-fracture, the zonulae occludentes are of variable apicobasal depth and consist of honeycomb-like meshworks of fibrils. Spaces of variable width frequently appear in the P-face grooves, indicating that the zonulae occludentes are "leaky." Numerous communicating (gap) junctions join the hepatocytes laterally. Varying numbers of lateral microvilli project into the intercellular spaces and, basally, the plasma membrane is deeply infolded, resulting in the formation of apparently interdigitating basal processes resting upon a thin basal lamina. Sinusoids are composed of both a heavily-fenestrated, continuous endothelium, and phagocytic reticulo-endothelial (Kupffer) cells. Depsite the difference in arrangement of their hepatocytes, the mammalian and lamprey livers show similar ultrastructural features.

Animals↗