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1

Centralny zegar biologiczny ptaków

100%
Prusik M.
Medycyna Weterynaryjna
|
2018
|
tom 74
|
nr 04
In birds many life processes runs in diurnal (e.g. locomotor activity, feeding, melatonin secretion) and seasonal rhythms (e.g. reproduction, song, feathering, migration) depending on the environmental light and the activity of their central clock system (CCS). The structure and mechanisms of the activity of the avian CCS are the most complex among vertebrates. CCS consists of three oscillators (in the retina, SCN and pineal gland) possessing their own sensory input system (photopigments) and effective output system (products for direct biological effects). So far, 14 forms of photopigments (Opn1, Opn2, Opn3, TMT, Opn4x, Opn4m, Opn5, RGR, RRH, VA-opsins, pinopsin, Cry1, Cry2 i Cry4) and 12 clock genes making up oscillators (Bmal1, Bmal2, Clock, NPas2 called also Mop4 and Rorα – positive genes and Cry1, Cry2, Cry4, Per2, Per3, E4bp4 and Rev-erbα – negative genes) have been described in the CCS in birds. Photopigments are placed in all layers of the retina; in the brain – mainly in regions of nuclei: septalis lateralis, premammillaris, habenularis and paraventricularis; in the pineal gland – in all kinds of pinealocytes. Most photopigments belonging to the opsin family are linked with the nucleotide phototransduction path, typical for vertebrates, but, in avian CCS, also the phosphoinositol phototransduction path, characteristic for invertebrates, exists and concerns Opn4x and Opn5. Oscilators are placed in nuclei of cells of all layers of the retina, in mSCN and vSCN (with great species variability) and in pinealocytes. It is supposed that all nonvisual photopigments have a direct role in the synchronization of the oscillator activity with the environmental light, but molecular the mechanisms of the interaction between photopigments and the oscillator remain unknown. The impact of each of the three oscillators of the CCS in the generation of biological rhythms in birds show great species differentiation. The differences concern both the domination of one of the oscillators over the others and the assignation of biological processes which the individual oscillator synchronizes rhythmically with the environmental light.
2

Regulacja sekrecji melatoniny w szyszynce ptakow

63%
Prusik M., Lewczuk B.
Medycyna Weterynaryjna
|
2008
|
tom 64
|
nr 05
639-645
The avian pineal gland releases melatonin in a cyclic manner, with the highest level at night and the lowest level during the daytime. Mechanisms regulating melatonin secretion in birds are very complex, probably due to the phylogenetic position of the avian pineal gland as an intermediate form between the pineals of lower vertebrates and mammals. Avian pinealocytes possess an endogenous oscillator, formed by a self-regulated system of cock genes, that controls the transcription of several enzymes, among them arylalkylamine N-acetyltransferase (AA-NAT), the enzyme limiting melatonin synthesis. These cells are also directly photosensitive due to the presence of photopigments, pinopsin and melanopsin, as well as corresponding signal transduction systems. Light acting via pinopsin induces a cascade of events that leads to the decrease in cGMP and cAMP levels, AA-NAT activity and melatonin secretion. Melanopsin is probably involved in an entrainment of the circadian oscillator to the environmental light conditions. The function of the avian pineal gland is also regulated by light acting indirectly via the retina as well as by the extrapineal oscillator located in the suprachiasmatic nucleus. Both structures influence the pinealocyte activity via a common multisynaptic pathway, which ends in the gland as the sympathetic nerve fibers. Norepinephrine released from these fibers stimulates α₂-adrenoreceptors in pinealocyte plasmalemma and inhibits adenylate cyclase activity and melatonin secretion. The significance of direct and indirect routes of light perception as well as intra- and extra-pineal oscillators in the regulation of melatonin secretion may differ between species, but this problem is poorly recognized.
3

Wielowymiarowość procesu rewitalizacji w ujęciu metodycznym

63%
Prusik M., Zrobek R.
Acta Scientiarum Polonorum. Administratio Locorum
|
2014
|
tom 13
|
nr 3
4

Budowa szyszynki ptakow

63%
Prusik M., Lewczuk B.
Medycyna Weterynaryjna
|
2008
|
tom 64
|
nr 06
764-769
The morphology of the avian pineal glands shows large interspecies variability. Considering the anatomic structure, six types of the pineal organs (I-VI) are distinguished in birds. They differ in the proportion between the distal and proximal parts of the gland as well as in the attachment to the intercommisural region. According to the histological structure, the avian pineal glands are classified into three types: the saccular, tubulo-follicular and solid type. The pineal parenchyma consists of pinealocytes, supporting cells and neurons. Among pinealocytes there are receptor pinealocytes (predominant in the saccular pineals), rudimentary-receptor pinealocytes (predominant in the tubulo-follicular organs) and secretory pinealocytes (most numerous in pineals of the solid type). The population of supporting cells consists of ependymal-like and astrocyte-like cells. Neurons are represented by afferent ganglion cells, present mainly in the saccular pineals. The pineals of tubulo-follicular and solid types possess well developed sympathetic innervation.
5

Indole metabolism in the embryonic pineal gland of the domestic turkey - a preliminary study

51%
Prusik M., Kwiecinska K., Lewczuk B.
Acta Biologica Cracoviensia. Series Botanica. Supplement
|
2016
|
tom 58
|
nr 1
6
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Calcium ions in the pig pineal gland - an ultracytochemical study

51%
Lewczuk B., Bulc M., Prusik M., Przybylska-Gornowicz B.
Journal of Elementology
|
2007
|
tom 12
|
nr 4
335-346
The aim of the study was to analyze the distribution of calcium ions in the pig pineal gland at the level of electron microscopy. The investigations were performed on the pineals obtained immediately after slaughter (performed between 11:30 and 12:00 a.m.) from 4-month-old gilts. The fixation procedures were conducted with the use of pyroantimonate, which reacted with calcium ions and formed electron dense precipitates. The precipitates were found both in the intercellular spaces and in cells - pinealocytes, gial cells, endothelial cells and fibroblasts. The precipitates were much more numerous in the intercellular spaces than in the cells. Amount and distribution of precipitates differed significantly between pinealocytes, therefore two types of cells were distinguished. The first type of pinealocytes included cells containing a small or moderate amount of precipitates. They were usually characterized by light or dark cytoplasm and large variability in number and structure of dense bodies. Pinealocytes classified to the second type possessed large or very large content of precipitates. These cells were characterized by electron dense cytoplasm and showed the presence of numerous dense bodies. In both types of pinealocytes, precipitates were present in the nucleus and in the cytoplasm. In nuclei, precipitates were numerous in nucleoplasma and rather infrequently noted between membranes of the nuclear envelope. In the cytoplasm deposits were found in mitochondria, vesicles and cisterns of smooth endoplasmic reticulum, in the Golgi apparatus and in cytosol. The amount of precipitates in glial cells, endothelial cells and fibrocytes was lower than in pinealocytes.
7
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Ultracytochemical localization of calcium ions in the pineal organ of the domestic turkey

51%
Lewczuk B., Prusik M., Ziolkowska N., Przybylska-Gornowicz B.
Journal of Elementology
|
2012
|
tom 17
|
nr 4
Calcium ions are involved in several processes occurring in the avian pineal, including the regulation of melatonin secretion. The aim of study was to investigate distribution of calcium ions in the pineal organ of domestic turkey at the level of electron microscopy. The study was performed on 12 female turkeys housed in a cycle of 12L : 12 D (light intensity 300 lux; 07:00 – 19:00), starting from the third week of life. At the age of 12 weeks, the birds were anesthetized with halothane and sacrificed by decapitation at 14:00 and at 02:00 (in darkness). The pineals were fixed using the potassium pyroantimonate method, which enables visualization of calcium ions in the form of electron dense precipitates. Extremely numerous, large precipitates of calcium pyroantimonate were observed between collagen fibres of the connective tissue surrounding the pineal follicles. The number of precipitates in the follicles was much lower than in the neighbouring stroma. Precipitates were numerous in intercellular spaces between cells forming the follicular wall. In contrast, they were infrequently observed in the follicular lumen. In pinealocytes, large amounts of precipitates were present in the nucleus, mitochondria and short, wide cisterns of the smooth endoplasmic reticulum. Precipitates were sparse in the apical prolongations of rudimentary-receptor pinealocytes. The content of precipitates did not differ prominently between individual pinealocytes. Precipitates in the cytosol of both rudimentary-receptor pinealocytes and secretory pinealocytes were much more numerous in the organs taken ex vivo during nighttime than during daytime. Supporting cells contained much fewer precipitates than pinealocytes.
8

Diurnal rhythm of plasma melatonin level in mares from spring equinox to summer solstice

51%
Rapacz A., Lewczuk B., Prusik M., Ras A.
Bulletin of the Veterinary Institute in Puławy
|
2010
|
tom 54
|
nr 4
The aim of this study was to describe plasma melatonin (MLT) profiles in mares from spring equinox to summer solstice. Two experiments were performed on 19 warm-blood mares: the first in a veterinary clinic and the second in a stable without electricity and located outside a village. In the first experiment, blood samples were collected at 2-h intervals during 50-h periods in March, April, May, June, and July. In the second experiment blood samples were drawn at 2-h intervals for 26 h in March. Plasma concentrations of MLT were measured by direct RIA. The mean plasma MLT level showed significant (P≤0.05) time-dependent changes in horses sampled in March, April, May, June, and July. In experiment I, the mean level of MLT was significantly elevated (compared to the day-time values at 12.00, 16.00, and 18.00) between 20.00 and 04.00 in March, and between 22.00 and 04.00 in April and May, between 24.00 and 04.00 in June and July. Therefore it could be concluded that the duration of the elevated MLT level reflects the length of scotophase, and merits consideration as an important signal in seasonal regulation of reproductive activity. Individual profiles of MLT level were well-entrained in the majority of animals studied in experiment I and in all individuals used in experiment II. The concentrations of plasma MLT varied between mares; however, in the vast majority of individuals, the plasma concentration of MLT was low compared to other mammalian species.
9
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Regulation of melatonin secretion in the pineal organ of the domestic duck - an in vitro study

51%
Prusik M., Lewczuk B., Ziolkowska N., Przybylska-Gornowicz B.
Polish Journal of Veterinary Sciences
|
2015
|
tom 18
|
nr 3
The aim of study was to determine the mechanisms regulating melatonin secretion in the pineal organs of 1-day-old and 9-month-old domestic ducks. The pineals were cultured in a superfusion system under different light conditions. Additionally, some explants were treated with norepinephrine. The pineal glands of 1-day-old ducks released melatonin in a well-entrained, regular rhythm during incubation under a 12 hrs light : 12 hrs dark cycle and adjusted their secretory activity to a reversed 12 hrs dark : 12 hrs light cycle within 2 days. In contrast, the diurnal changes in melatonin secretion from the pineals of 9-month-old ducks were largely irregular and the adaptation to a reversed cycle lasted 3 days. The pineal organs of nestling and adult ducks incubated in a continuous light or darkness secreted melatonin in a circadian rhythm. The treatment with norepinephrine during photophases of a light-dark cycle resulted in: 1) a precise adjustment of melatonin secretion rhythm to the presence of this catecholamine in the culture medium, 2) a very high amplitude of the rhythm, 3) a rapid adaptation of the pineal secretory activity to a reversed light-dark cycle. The effects of norepinephrine were similar in the pineal organs of nestlings and adults. In conclusion, melatonin secretion in the duck pineal organ is controlled by three main mechanisms: the direct photoreception, the endogenous generator and the noradrenergic transmission. The efficiency of intra-pineal, photosensitivity-based regulatory mechanism is markedly lower in adult than in nestling individuals.
10
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Adrenergic control of pinealocyte chondriome - an in vitro study

51%
Przybylska-Gomowicz B., Lewczuk B., Ziolkowska N., Prusik M.
Polish Journal of Veterinary Sciences
|
2016
|
tom 19
|
nr 4
Norepinephrine released from sympathetic innervation plays the main role in the regulation of melatonin secretion in mammalian pinealocytes. The present study was conducted for the following reasons: 1) to establish whether the pinealocyte chondriome is controlled by norepinephrine, 2) to determine the effect of adrenergic stimulation on mitochondria, and 3) to characterize adrenoceptors involved in the regulation of the chondriome. The static organ culture of the pineal gland was used. The explants were incubated for 5 consecutive days in control medium and between 20:00 and 08:00 in medium with the presence of 10 μM norepinephrine – adrenergic agonist; isoproterenol – beta-adrenoceptor agonist; cirazoline, methoxamine, M-6364 – alfa1 – adrenoceptors agonists or PMA – activator of PKC. The explants were then subjected to ultrastructural examination and morphometric analysis. The incubation of explants in the presence of norepinephrine or isoproterenol caused a decrease in the relative volume and the numerical density of mitochondria and induced an increase in the percentage of free mitochondria in pinealocytes. Significant changes in these parameters were not observed after treatment with methoxamine, cirazoline, M-6463 and PMA. The results obtained show that the chondriome of pig pinealocytes is controlled by norepinephrine acting via beta-adrenoceptors. Adrenergic stimulation, repeated for five consecutive days of organ culture, causes a decrease in the number of mitochondria and a shift in the distribution of mitochondria from the form of networks and filaments into the form of single particles. This indicates the intensive remodeling of the mitochondria network, which is closely linked to the metabolic status of the cell.
11

Dysplazja siatkówki u psów i kotów - aktualny stan wiedzy

51%
Ziolkowska N., Prusik M., Ziolkowski H.
Medycyna Weterynaryjna
|
2012
|
tom 68
|
nr 01
Retinal dysplasia is an abnormal growth and differentiation of the retina during the embryonic and early postnatal life. It is characterized by linear folds of the sensory retina and the formation of rosettes composed of variable numbers of neuronal cells. The morphologic classification of retinal dysplasia in dogs includes single or multiple folds, geographic retinal dysplasia, and retinal dysplasia accompanied by retinal detachment and by other systemic abnormalities. There are multiple potential etiologies for retinal dysplasia, including genetic mutations, viruses, toxins and irradiation. Heritable forms of retinal dysplasia have been reported in many breeds of dogs. Mutations that induce retinal dysplasia have not yet been identified. The aim of this paper was to present selected aspects of retinal dysplasia in dogs and cats.
12

Release of N-acetylserotonin and melatonin from the embryonic pineal organs of the domestic turkey in the superfusion culture

51%
Prusik M., Hanuszewska M., Petrusewicz-Kosinska M., Lewczuk B.
Acta Biologica Cracoviensia. Series Botanica. Supplement
|
2018
|
tom 60
|
nr 1
13

Ontogenesis of melatonin synthesis pathway in the goose pineal organ

51%
Hanuszewska M., Prusik M., Martyniuk K., Lewczuk B.
Acta Biologica Cracoviensia. Series Botanica. Supplement
|
2018
|
tom 60
|
nr 1
14

Diurnal rhythms of pinealocyte ultrastructure, pineal serotonin content and plasma melatonin level in the domestic pig

51%
Lewczuk B., Nowicki M., Prusik M., Przybylska-Gornowicz B.
Folia Histochemica et Cytobiologica
|
2004
|
tom 42
|
nr 3
15

Calcium concrements in the pineal gland of the Arctic fox (Vulpes lagopus) and their relationship to pinealocytes, glial cells and type I and III collagen fibers

45%
Bulc M., Lewczuk B., Prusik M., Gugolek A., Przybylska-Gornowicz B.
Polish Journal of Veterinary Sciences
|
2010
|
tom 13
|
nr 2
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