Wyniki wyszukiwania

1

Hypoxia-induced subcellular migration of calcium in the carotid body: an ultrastructural assessment by ion-capture cytochemistry

100%

Pokorski M., Walski M.

Cellular and Molecular Biology Letters

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2002

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tom 07

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nr Suppl.

2

Hypoxic ventilatory profile in the anesthetized rat

86%

Marczak M., Kolesnikova E. E., Pokorski M.

Journal of Physiology and Pharmacology. Supplement

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2004

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tom 55

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nr 3

89-94

In the present study we investigated whether hypocapnia that accompanies hypoxic hyperventilation might affect the biphasic, stimulatory/depressant, ventilatory response to hypoxia. The experiments were carried out in anesthetized, vagotomized, spontaneously breathing, and poikilocapnic rats. The animals were subjected to acute steady-state hypoxia consisting of 12% O2 in N2 in inspiratory mixture. Ventilation and its frequency and volume components were assessed from the integrated electromyographic activity of the diaphragm. We found that despite the development of significant hypocapnia, the hypoxic ventilatory response consisted of rapid stimulation followed by a gradual decline. The frequency component contributed more to the ventilatory increase than that of volume. The results indicate that the hypoxic ventilatory profile in the anesthetized poikilocapnic rat resembles that known to be present during isocapnia. We conclude that hypocapnia neither hampers the hypoxic ventilatory reactivity nor alters the biphasic hypoxic ventilatory profile. These observations may aid planning experimental rat model studies.

3

Ultrastructural degradation of the carotid body in the aged rat: is there a role for atherosclerosis in the main carotid arteries?

86%

Dymecka A., Walski M., Pokorski M.

Journal of Physiology and Pharmacology. Supplement

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2006

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tom 57

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nr 4

85-90

In this study we examined the potential role of atherosclerosis in the main arteries supplying blood to the carotid body in the organ’s morphological degradation with age. We addressed this issue by comparing the ultrastructural picture of carotid bodies and of fragments of the carotid artery bifurcation in two age-extreme groups of rats: young - 3 months old and senescent - 24 months old. Tissues were excised under surgical anesthesia, fixed in aldehydes, and processed for transmission electron microscopy. We found that the old carotid body parenchyma exhibited profound degenerative changes. Chemoreceptor cells were at various stages of atrophy, ranging from swollen mitochondria and fewer secretory vesicles to dark dehydrated cells. In contrast, the senescent carotid artery bifurcation was little different from that in young rats. Particularly, endothelial cells were in perfect condition. There were some changes in deeper arterial wall layers such as breaks in the continuity of elastic bands or a subtly different phenotype of smooth muscle cells. No foam cells or calcium build-ups were found in the arterial walls. Such changes correspond to the process of arterial wall stiffening in old age rather than to the outright atherosclerosis. Lack of atherosclerosis in the common carotid arteries, which could hamper blood flow, argues against its playing a role in the morphological age-changes in the carotid bodies.

4

Study of the carotid body in the cat with special reference to its innervation. I. Light microscopy

86%

Bengoechea M. E., Vega-Alvarez J. A., Lopez Muniz A., Anibarro M. D., Perez-Casas A.

Folia Morphologica

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1988

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tom 47

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nr 1-4

5

The aging corotid body

72%

Pokorski M., Walski M., Dymecka A., Marczak M.

Journal of Physiology and Pharmacology. Supplement

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2004

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tom 55

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nr 3

107-113

The respiratory system is subject to the aging process, which could limit its responsiveness to hyperventilatory stimuli. Attenuation of the ventilatory response to hypoxia in old age is, as yet, an unresolved issue. Such attenuation may be germane for the pathogenesis of respiratory disorders developing more often in elderly subjects. The aim of this study was to determine the potential adverse effects of age on the morphology and function of carotid bodies. Morphology was studied at the level of electron microscopy on carotid bodies dissected from adult young (3 months) and old (>2 years) rats and function by comparing the hypoxic ventilatory response in populations of young (mean age 24 years) and old (mean age 71 years) female subjects. The human protocol consisted of a progressive hypoxia test, based on a rebreathing technique in a closed system. The hypoxic ventilatory response was evaluated from the slopes of minute ventilation on arterial oxygen saturation. The results of the morphological study showed degenerative changes developing with age in the ultrastructure of carotid bodies. On the other side, respiratory responses to hypoxia in old women were well preserved and were no less than those in young women. Therefore, a discrepancy appeared between the morphological and functional aspects. These findings suggest development of compensatory mechanisms in brain respiratory areas which maintain primary defensive reflexes, such as the hyperventilation of hypoxia.

6

Age-related peculiarities of breathing regulation and antioxidant enzymes under intermittent hypoxic training

72%

Kolesnikova E. E., Safronowa O. S., Serebrovskaya T. V.

Journal of Physiology and Pharmacology. Supplement

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2003

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tom 54

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nr 1

20-24

Aging is associated with changes in breathing regulation, particularly, in respiratory sensitivity to hypoxic stimuli. One theory of aging holds that reactive oxygen species play a key role in this process. These species have also been implicated in the carotid body O2 sensing. In the present study we investigated hypoxic ventilatory responses (HVR) and antioxidant enzymes activity in healthy young and elderly people under a 14-day adaptation to intermittent hypoxic training (IHT). The elderly demonstrated decreased HVR and blood catalase (CAT) activity on a background of strong negative correlation between the levels of end-tidal CO2 tension and superoxide dismutase (SOD) activity. The adaptation to IHT resulted in increased HVR and SOD activity in both groups, and decreased CAT activity in young persons compared with its augmentation in the elderly. Increased SOD activity testifies to an overproduction of reactive oxygen species during IHT. We hypothesize that reactive oxygen species might potentiate a periodical augmentation of cytosolic Ca2+ in the carotid body. This, in turn, might determine an increase in tyrosine hydroxylase gene expression and promote neurotransmitter synthesis/release, resulting in enhanced HVR.

7

A common oxygen sensor regulates the sensory discharge and glomus cell HIF-1alpha in the rat carotid body

72%

Lahiri S., Antosiewicz J., Pokorski M.

Journal of Physiology and Pharmacology. Supplement

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2007

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tom 58

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nr 5

8

Influence of the stimulation of carotid body chemoreceptors on the gastric mucosal blood flow in artificially ventilated and spontaneously breathing rats

72%

Sinski M., Kowalczyk P., Stolarczyk A., Sawionek L., Przybylski J.

Journal of Physiology and Pharmacology

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2002

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tom 53

|

nr 3

The cardiovascular effects of the stimulation of arterial chemoreceptors are different in spontaneously breathing and artificially ventilated animals. Respiratory failure and long term sojourn at high altitude coincide frequently with the occurrence of gastric ulceration. In both these situations a profound stimulation of arterial chemoreceptors is present. The purpose of the paper was to investigate the reflex effect of stimulation carotid chemoreceptors on gastric mucosal blood flow in the rat. Arterial chemoreceptors were stimulated by two methods (I) substitution gas mixture of 10% oxygen in nitrogen for room air and (II) direct injection of acid saline ( 0.05 ml, pH=6.8) into the distal part of left common carotid artery. In artificially ventilated rats stimulation of arterial chemoreceptors caused significant increase in gastric mucosal vascular resistance, accompanied by marked decline in blood flow. This effect was mediated by adrenergic mechanism. On the contrary to artificially ventilated rats, decline of gastric mucosal vascular resistance with concomitant increase in blood flow was found in spontaneously breathing animals. This effect was not abolished either by phentolamine or atropine. As vasodilatatory effect of arterial chemoreceptors stimulation was abolished by bilateral vagotomy, we postulate that non adrenergic and non cholinergic vagal fibers mediate observed vascular changes in gastric mucosa in spontaneously breathing rats. We hypothesize that in artificially ventilated patients with respiratory failure stimulation of arterial chemoreceptors by hypoxemia and or acidosis may contribute to the development of gastric mucosal lesions.

9

Apnoeic responses to intracarotid nicotine challenge in anaesthetized cats

72%

Szereda-Przestaszewska M., Kopczynska B.

Journal of Physiology and Pharmacology

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2003

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tom 54

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nr 2

To determine the effects of an intraarterial administration of nicotine on the occurrence of apnoea and the activity of rib cage respiratory muscles, we studied 31 anaesthetized, spontaneously breathing cats. Phrenic activity was used as an index of neural inspiratory drive. Activity of parasternal intercostal (PIM) and triangularis sterni (TS) muscles was recorded. Nicotine in a dose of 65 µg/kg was injected into the left common carotid artery prior to and after midcervical vagotomy, preceded by section of the superior laryngeal nerves (SLNs). In eight additional cats, initially neurotomized as mentioned, nicotine was injected after bilateral disruption of the carotid sinus nerves (CSNs). Nicotine induced prompt expiratory apnoea of mean duration of 5.4±0.3 s in 19 non-vagotomized and of 5.92±0.51 s (mean±S.E.M.) in 13 vagotomized cats. The occurrence and duration of the temporary arrest of breathing were reduced by midcervical vagotomy but not by subsequent CSNs neurotomy, which abolished post-apnoeic acceleration of breathing.In post-nicotine breathing of increased tidal volume and respiratory rate, peak activity of the parasternal intercostal muscles increased from baseline of 3.2±1.2 to 9.5±2.0 arbitrary units (p<0.001). The peak height of the phrenic nerve elevated from 7.9±0.9 to 14.5±1.7 arbitrary units (p<0.001). That of the triangularis sterni showed no change.The response of the respiratory effectors elicited by nicotine was independent of the vagal integrity and may be attributed to activation of nicotine receptors within the brainstem respiratory neurones.

10

NADPH-diaphorase in the cat carotid body

72%

Walski M., Pokorski M.

Acta Neurobiologiae Experimentalis

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2000

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tom 60

|

nr 1

11

Transient O2-dependent effects of CO2 on ventilation in the anesthetized mouse

72%

Pokorski M., Izumizaki M., Homma I.

Journal of Physiology and Pharmacology

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2005

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tom 56

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nr 3

In this study we sought to determine the effects of background hyperoxia on the ventilatory response to hypercapnia. We addressed this issue by examining the temporal profile of the first minute transients of minute ventilation, and its frequency and tidal components, in response to 5% and 10% CO2 each co-applied with the natural (balanced with air) and hyperoxic (balanced with O2) levels of oxygen. The study was performed on the urethane-anesthetized, tracheostomized, spontaneously breathing mouse, placed in a flow-through body plethysmograph. We identified an early suppressant effect of CO2-in-O2 on breathing frequency. The frequency declined to 88.5 ±1.4% and 87.8 ±1.9% relative to the pre-test, baseline level for 5% and 10% CO2, respectively. There was a compensatory rise in tidal volume and no major change in the overall ventilation. In contrast, CO2-in-Air resulted in ventilatory stimulation caused in equal measure by frequency and tidal components. Thus, the inhibitory effect on breathing frequency of the CO2-in-O2 resulted from the O2 content in the mixture and had the temporal characteristics consistent with carotid body function. In conclusion, transient O2-dependent effects can bear on the nascent hypercapnic ventilatory response. The complexity of the O2-CO2 interaction regarding the breathing pattern components should be taken into account while designing the optimal conditions for a hypercapnic test.

12

Poly(ADP-ribose) polymerase activity in the cat carotid body in hypoxia and hyperoxia

72%

Strosznajder R. P., Jesko H., Pokorski M.

Journal of Physiology and Pharmacology

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2002

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tom 53

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nr 3

Reactive oxygen species (ROS) induce DNA damage with the ensuing activation of the chromosomal repair enzyme poly(ADP-ribose) polymerase (PARP). ROS also interact with the function of carotid body chemoreceptor cells. The possibility arises that PARP is part of the carotid chemosensing process. This study seeks to determine the presence of PARP and its changes in response to contrasting chemical stimuli, hypoxia and hyperoxia, both capable of generating ROS, in cat carotid bodies. The organs were dissected from anesthetized cats exposed in vivo to acute normoxic (PaO290 mmHg), hypoxic (PaO225 mmHg), and hyperoxic (PaO2> 400 mmHg) conditions. Carotid body homogenate was the source of PARP and [adenine 14C] NAD was the substrate in the assay. Specimens of the superior cervical ganglion and brainstem were used as reference tissues. We found that PARP activity amounted to 27 pmol/mg protein/min in the normoxic carotid body. The activity level more than doubled in both hypoxic and hyperoxic carotid bodies. Changes of PARP in the reference tissues were qualitatively similar. We conclude that PARP is present in the carotid body but the augmentation of the enzyme activity in both hypoxia and hyperoxia reflects DNA damage, induced likely by ROS and being universal for neural tissues, rather than a specific involvement of PARP in the chemosensing process.

13

Aging and expression of heme oxygenase-1 and endothelin-1 in the rat carotid body after chronic hypoxia

58%

Di Giulio C., Verratti V., Artese L., Petruccelli G., Walski M., Pokorski M.

Journal of Physiology and Pharmacology. Supplement

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2009

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tom 60

|

nr 5

14

Altitude adaptation through hematocrit changes

58%

Zubieta-Calleja G. R., Paulev P.-E., Zubieta-Calleja L., Zubieta-Castillo G.

Journal of Physiology and Pharmacology. Supplement

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2007

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tom 58

|

nr 5

15

Acute hypoxia modulates arachidonic acid metabolism in cat carotid bodies. Role of dopamine

58%

Strosznajder R. P.

Acta Neurobiologiae Experimentalis

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1996

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tom 56

|

nr 2

16

Protein kinase C in the carotid body

58%

Pokorski M., Faff L.

Acta Neurobiologiae Experimentalis

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1999

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tom 59

|

nr 2

17

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ATP activates phospholipase C in the cat carotid body in vitro

58%

Pokorski M., Strosznajder R.

Journal of Physiology and Pharmacology

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1997

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tom 48

|

nr 3

Ograniczanie wyników

Hypoxia-induced subcellular migration of calcium in the carotid body: an ultrastructural assessment by ion-capture cytochemistry

Hypoxic ventilatory profile in the anesthetized rat

Ultrastructural degradation of the carotid body in the aged rat: is there a role for atherosclerosis in the main carotid arteries?

Study of the carotid body in the cat with special reference to its innervation. I. Light microscopy

The aging corotid body

Age-related peculiarities of breathing regulation and antioxidant enzymes under intermittent hypoxic training

A common oxygen sensor regulates the sensory discharge and glomus cell HIF-1alpha in the rat carotid body

Influence of the stimulation of carotid body chemoreceptors on the gastric mucosal blood flow in artificially ventilated and spontaneously breathing rats

Apnoeic responses to intracarotid nicotine challenge in anaesthetized cats

NADPH-diaphorase in the cat carotid body

Transient O2-dependent effects of CO2 on ventilation in the anesthetized mouse

Poly(ADP-ribose) polymerase activity in the cat carotid body in hypoxia and hyperoxia

Aging and expression of heme oxygenase-1 and endothelin-1 in the rat carotid body after chronic hypoxia

Altitude adaptation through hematocrit changes

Acute hypoxia modulates arachidonic acid metabolism in cat carotid bodies. Role of dopamine

Protein kinase C in the carotid body

ATP activates phospholipase C in the cat carotid body in vitro