Molecular Biology of Chemoreceptor Function: Induction of Tyrosine Hydroxylase in the Rat Carotid Body Elicited by Hypoxia

Hanbauer, Ingeborg

doi:10.1007/978-3-642-66755-8_17

Cited by 5 publications

(4 citation statements)

References 15 publications

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“…In the CB chemoreceptors, the available literature on second messengers deals with cyclic AMP (CAMP). The disparity in absolute cAMP levels reported, as well as in the observations made under natural (hypoxic) stimulation (Fitzgerald et al, 1977;Hanbauer, 1977;Mir et al, 1983;Delpiano et al, 1984), do not allow any conclusions to be drawn regarding the involvement of this nucleotide in the chemoreception process.…”

mentioning

confidence: 95%

Effects of Different Types of Stimulation on Cyclic AMP Content in the Rabbit Carotid Body: Functional Significance

Pérez-Garcı́a

Almaraz

González

1990

Journal of Neurochemistry

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Cyclic AMP levels in rabbit carotid bodies incubated under control conditions, 100% O2- or 95% O2/5% CO2- equilibrated medium, are close to 1 pmol/mg wet tissue (range 0.4-2.43 pmol/mg). Isobutylmethylxanthine (0.5 mM) increases cyclic AMP levels by a factor of 14 and 8 in HEPES- and CO2/CH3O(-)-buffered medium, respectively. Forskolin (0.5-10 microM) applied during 30 min increases cyclic AMP levels in a dose-dependent manner. Incubation of carotid bodies at low O2 tensions resulted in an elevation of cyclic AMP levels both in the absence and in the presence of isobutymethylxanthine. In the latter conditions cyclic AMP increase was maximum at an O2 tension of 46 mm Hg and tended to decrease at extremely low PO2. In isobutylmethylxanthine-containing Ca2(+)-free medium, cyclic AMP increased linearly with decreasing PO2 from 66 to 13 mm Hg; the absolute cyclic AMP levels attained in Ca2(+)-free medium were smaller than those observed in Ca2(+)-containing medium at any PO2. The differences between Ca2(+)-free and Ca2(+)-containing media appear to be due to the action of released neurotransmitters in the latter conditions, because dopamine and norepinephrine, which are known to be released by hypoxia in a Ca2(+)-dependent manner, increase cyclic AMP in the carotid body. Low pH/high PCO2 and high [K+]e increase cyclic AMP levels only in Ca2(+)-containing medium. Forskolin potentiates the release of catecholamines induced by low PO2. These results suggest that cyclic AMP plays an important role in the modulation of the chemoreception process.

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confidence: 95%

Effects of Different Types of Stimulation on Cyclic AMP Content in the Rabbit Carotid Body: Functional Significance

Pérez-Garcı́a

Almaraz

González

1990

Journal of Neurochemistry

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“…При этом остается непонятным повышенный (хотя значительно более низкий, чем у крыс и мышей) уровень тирозингидроксилазы в случаях № 3 и № 7. Согласно данным литературы, количество тирозингидроксилазы в органе повышается в ответ на воздействие хронической гипоксии [17]. Однако в этих двух случаях нет никаких данных, свидетельствующих о наличии у пациентов длительной хронической гипоксии.…”

Section: Discussionunclassified

Immunohistochemical features of the human carotid body

Junemann

Tsvetkova

Gorokhov

et al. 2020

Clin. Exp. Morphology

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Introduction. The carotid body is a chemoreceptor organ and the initial link of the reflex regulation of car-diovascular and respiratory systems. However, molecular genetic and immunohistochemical characteristics of the human carotid body remains underinvestigated. Although there are numerous studies of the second half of the 20th century devoted to the classical light-optical histology of the human organ, the immunohis-tochemical investigations are very few. The aim of our study was to clarify immunohistochemical features of the human carotid body in comparison with those of the most commonly used laboratory animals. Materials and methods. The study was performed on 10 carotid bodies of the adult human of different ages of both sexes using immunoperoxidase labeling with antibodies to bIII-tubulin, tyrosine hydroxylase, syn-aptophysin, PGP9.5, neurofilaments 200kDa, S100, and GFAP. Results. Nerve fibers passing between the lobules, as well as entering them, were positive for bIII-tubulin, tyrosine hydroxylase, PGP9.5 and neurofilaments. Type I cells had cytoplasmic reaction for bIII-tubulin and synaptophysin as well as cytoplasmic and nuclear staining for PGP9.5. At the same time, they had weaker reaction for tyrosine hydroxylase. Type II cells were positive for GFAP and S100. Conclusion. Immunohistochemical characteristics of the human carotid body were similar to those of rats and mice. The human carotid body cells and nerve fibers showed the same distribution of PGP9.5, bIII-tubulin, synaptophysin, neurofilaments, GFAP and S100 as rat and mouse carotid body cells. However, human carotid body reaction for tyrosine hydroxylase was much lower, which may indicate a smaller amount of synthesized catecholamines compared to the carotid body in rats and mice. Keywords: human carotid body, immunohistochemistry, sympathoadrenal system, tyrosine hydroxylase

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“…The concentration of catecholamines in type-I cells was shown to be almost seven times higher than that in other cells of the carotid body [25]. This concentration in type-I cells changes significantly under the influence of hypoxia, which also reduces the concentration of noradrenaline [381 and dopamine [39,40]. It seems likely that the dopamine concentration is most labile, its changes occurring due to output of dopamine from type-I cells rather than to blockade of dopamine synthesis [40].…”

Section: Role Of Dopamine In Reception Of the Oxygen Levelmentioning

confidence: 99%

“…Practically all data of neurochemical studies in vitro suggest that dopamine is an excitatory neurotransmitter in the carotid bodies [23,72 ]. In particular, it was shown [39] that acute hypoxia is followed by an increase in the content of tyrosine hydroxylase and by enhancement of dopamine synthesis in the carotid bodies. All chemostimulatory agents tested in vitro, including such natural stimuli as low partial pressure of oxygen, high COs level, or low pH, increased dopamine release in direct proportion to their intensity and concurrently with an increase of impulsation in the carotid sinus nerve.…”

Section: Role Of Dopamine In Reception Of the Oxygen Levelmentioning

confidence: 99%