Osmoregulatory Role of Prolactin in Lower Vertebrates

2015 ◽  
pp. 112-124 ◽  
Author(s):  
T. Hirano ◽  
T. Ogasawara ◽  
J. P. Bolton ◽  
N. L. Collie ◽  
S. Hasegawa ◽  
...  
Keyword(s):  
Lower Vertebrates

scholarly journals Cardiac regeneration: epicardial mediated repair

2015 ◽  
Vol 282 (1821) ◽  
pp. 20152147 ◽  
Author(s):  
Teresa Kennedy-Lydon ◽  
Nadia Rosenthal
Keyword(s):  
Stem Cells ◽  
Endothelial Cells ◽  
Cardiac Fibroblasts ◽  
Cardiac Regeneration ◽  
Repair Process ◽  
Regenerative Process ◽  
Cardiac Stem Cell ◽  
Cardiomyocyte Proliferation ◽  
Lower Vertebrates

The hearts of lower vertebrates such as fish and salamanders display scarless regeneration following injury, although this feature is lost in adult mammals. The remarkable capacity of the neonatal mammalian heart to regenerate suggests that the underlying machinery required for the regenerative process is evolutionarily retained. Recent studies highlight the epicardial covering of the heart as an important source of the signalling factors required for the repair process. The developing epicardium is also a major source of cardiac fibroblasts, smooth muscle, endothelial cells and stem cells. Here, we examine animal models that are capable of scarless regeneration, the role of the epicardium as a source of cells, signalling mechanisms implicated in the regenerative process and how these mechanisms influence cardiomyocyte proliferation. We also discuss recent advances in cardiac stem cell research and potential therapeutic targets arising from these studies.

Role of Nitric Oxide in Control of Light Adaptive Cone Photomechanical Movements in Retinas of Lower Vertebrates: A Comparative Species Study

Nitric Oxide ◽  
2002 ◽  
Vol 6 (2) ◽  
pp. 200-204 ◽  
Author(s):  
A.R. Angotzi ◽  
J. Hirano ◽  
S. Vallerga ◽  
M.B.A. Djamgoz
Keyword(s):  
Nitric Oxide ◽  
Lower Vertebrates ◽  
Species Study

Comparative studies on glial markers

1981 ◽  
Vol 95 (1) ◽  
pp. 167-180
Author(s):  
B. I. Roots
Keyword(s):  
Manduca Sexta ◽  
Comparative Studies ◽  
Nervous Tissue ◽  
Functional Role ◽  
Functional Interactions ◽  
Lower Vertebrates ◽  
Fresh Insight ◽  
Insight Into ◽  
Biochemical Differentiation

Macromolecular markers for glial cells have been sought for a variety of reasons. One of the earliest was the need for a means of assessing the purity of cell and subcellular fractions prepared from nervous tissue. While there is still a requirement for this kind of tool, emphasis has shifted towards seeking information on biochemical differentiation among cells and their functional interactions. A brief general review will be made of glial markers and two of these, 2′,3′-cyclic nucleotide 3′-phosphohydrolase (CNP) and glutamine synthetase (GS), will be considered in detail. Until recently studies of markers have been concentrated on the higher vertebrates and those on lower vertebrates and invertebrates have hardly begun. However, such comparative studies may lead to fresh insight into old problems. For example, CNP has long been regarded as a marker for myelin and oligodendrocytes but it has not been possible to attribute a functional role to it and its relation to myelination has remained obscure. The finding that it is present in the glia of a moth Manduca sexta which lacks myelin provides a stimulus for a fresh approach to the problem. Another example is provided by studies on GS. This enzyme is found in astrocyte feet and preliminary results indicate that it is localized also in the perineurial glia of Aplysia ganglia. These results lead to a reconsideration of the perennial question of the possible role of astrocyte feet in barrier mechanisms. Extension of comparative studies may not only raise new questions but also provide some answers.

scholarly journals Peripheral Receptors Affecting Breathing and Cardiovascular Function in Non-Mammalian Vertebrates

1982 ◽  
Vol 100 (1) ◽  
pp. 59-91 ◽  
Author(s):  
David R. Jones ◽  
William K. Milsom
Keyword(s):  
Gas Exchange ◽  
Wide Distribution ◽  
Cell Complexes ◽  
Arterial Blood ◽  
Normal Breathing ◽  
Lower Vertebrates ◽  
The Central Nervous System ◽  
Circulatory Reflexes ◽  
Stimulus Modalities

Most vertebrates show respiratory and circulatory reflexes which can be traced to stimulation of various extero- or interoceptors. Widely distributed groups of exteroceptors, with a variety of stimulus modalities, are associated with defence reflexes which protect the respiratory passages and gas exchange surfaces. Other exteroceptors are associated only with the gas exchange surfaces. These are either mechanoreceptors or chemoreceptors and have a range of different dynamic characteristics, but are none-the-less amazingly uniform in their role in control of the normal breathing pattern. Intravascular receptors stimulated by the arterial blood pressure are located on all the gills in fishes, yet appear to be restricted to the pulmocutaneous arteries in anuran amphibians and to the truncal region or aortic root in reptiles and birds. On the other hand, the distribution of glomus-sustentacular-nerve cell complexes, associated with intravascular chemoreception, appears to be much more diffuse in higher than lower vertebrates. The wide distribution of these cell complexes may be attributed to their embryological origin from neural crest cells. Even so, the presence of these complexes does not appear to be essential for respiratory responses to environmental hypoxia since they have not been located in teleost fishes. The role of peripheral receptors in controlling cardiovascular and respiratory functions, under steady state conditions in non-mammalian vertebrates, is not well defined and it may be that they are only modulators of circulatory and respiratory patterns arising from hormonal or humoral effects on the central nervous system.

Role of LPXRFamide peptide in the neuroendocrine regulation of reproduction in fish

2011 ◽  
Vol 6 (5) ◽  
pp. 853-860 ◽  
Author(s):  
Md. Shahjahan ◽  
Hironori Ando
Keyword(s):  
Gonadal Development ◽  
Gonadotropin Releasing Hormone ◽  
Fish Reproduction ◽  
Lower Vertebrates ◽  
Hypothalamic Control ◽  
G Protein Coupled ◽  
Made In

AbstractThe decapeptide gonadotropin-releasing hormone (GnRH) is the primary factor responsible for the hypothalamic control of gonadotropin (GTH) secretion. This review focuses on a family of neuropeptides, LPXRFamide (LPXRFa) peptides, which have been implicated in the regulation of GTH secretion. LPXRFa acts on the pituitary via a G protein-coupled receptor, LPXRFa-R, to enhance gonadal development and maintenance by increasing gonadotropin release and synthesis. Because LPXRFa exists and functions in several fish species, LPXRFa is considered to be a key neurohormone in fish reproduction control. The precursors to LPXRFamide peptides encoded plural LPXRFamide peptides and were highly divergent in vertebrates, particularly in lower vertebrates. Tissue distribution analyses indicated that LPXRFamide peptides were highly concentrated in the hypothalamus and other brainstem regions. In view of the localization and expression of LPXRFamide peptides in the hypothalamo-hypophysial system, LPXRFamide peptide in fish increase GTH release in vitro and in vivo. This review summarizes the advances made in our understanding of the biosynthesis, mode of action and functional significance of LPXRFa, a newly discovered key neurohormone.

Gene structure of urea transporters

2003 ◽  
Vol 284 (1) ◽  
pp. F3-F10 ◽  
Author(s):  
Serena M. Bagnasco
Keyword(s):  
Transcriptional Control ◽  
Molecular Mechanisms ◽  
Physiological Role ◽  
Renal Physiology ◽  
The Past ◽  
New Information ◽  
Lower Vertebrates ◽  
Genes Encoding ◽  
Concentrate Urine

Urea plays various roles in the biology of diverse organisms. The past decade has produced new information on the molecular structure of several urea transporters in various species. Availability of DNA probes has revealed that the presence of urea transporters is not confined to the mammalian kidney but is also evident in testis and brain, raising new questions about the possible physiological role of urea in these organs. Cloning of the genes encoding the two closely related mammalian urea transporters UT-A and UT-B has helped in identifying molecular mechanisms affecting expression of urea transporters in the kidney, such as transcriptional control for UT-A abundance. On the basis of analysis of genomic sequences of individuals lacking the UT-B transporter, mutations have been found that explain deficits in their capacity to concentrate urine. More urea transporters are being characterized in marine organisms and lower vertebrates, and studying the role and regulation of urea transport from an evolutionary perspective can certainly enrich our understanding of renal physiology.

scholarly journals cerebral asymmetry: from survival strategies to social behaviour

2005 ◽  
Vol 28 (4) ◽  
pp. 613-614
Author(s):  
jechil sieratzki ◽  
bencie woll
Keyword(s):  
Social Behaviour ◽  
Young Infant ◽  
Survival Strategies ◽  
Cerebral Asymmetry ◽  
Group Behaviour ◽  
Species Survival ◽  
Lower Vertebrates ◽  
The Individual ◽  
Human Social Behaviour

we describe a possible link between coordinated lateralised group behaviour serving species survival in lower vertebrates and a striking lateralisation phenomenon found in human social behaviour: the universal preference for cradling a young infant on the left side. our exploration offers a different perspective on the role of cerebral asymmetry for the survival of both the individual and the species.

scholarly journals Light-adaptive role of nitric oxide in the outer retina of lower vertebrates: a brief review

2000 ◽  
Vol 355 (1401) ◽  
pp. 1199-1203 ◽  
Author(s):  
Mustafa B. A. Djamgoz ◽  
Sumathi Sekaran ◽  
A. Rita Angotzi ◽  
Sakineh Haamedi ◽  
Silvana Vallerga ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Light Adaptation ◽  
Horizontal Cell ◽  
Cell Activity ◽  
Outer Retina ◽  
No Donors ◽  
Lower Vertebrates ◽  
Gap Junctional ◽  
Adaptive Role

The role of nitric oxide (NO) as a novel neurochemical mechanism controlling light adaptation of the outer retina is discussed by considering mainly published results. The emphasis is on the retinae of fishes and amphibia, but some data from the mammalian (rabbit) retinae have also been included for completeness. In the fish retina, application of NO donors in the dark caused light–adaptive photomechanical movements of cones. The normal effect of light adaptation in inducing cone contractions was suppressed by pretreatment of retinae with an NO scavenger. NO donors modulated horizontal cell activity by uncoupling the cells' lateral gap junctional interconnections and enhancing negative feedback to cones, again consistent with a light–adaptive role of NO. Direct evidence for light adaptation–induced release of NO has been obtained in fish (carp) and rabbit retinae. The results strongly suggest that control of retinal light adaptation is under multiple neurochemical control, with NO and dopamine having an interactive role.

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