Increased density of perivascular nerves to the major cerebral vessels of the spontaneously hypertensive rat: differential changes in noradrenaline and neuropeptide Y during development

Dhital, K.; Gerli, R; Lincoln, J.; Milner, P.; Tanganelli, Piero; Weber, G.; Fruschelli, C; Burnstock, Geoffrey

doi:10.1016/0006-8993(88)90910-9

Cited by 59 publications

(25 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have shown, as previously reported, that by this age the rats are already hypertensive [18]. The question we need to ask is whether increased neural ET in hypertensive rats is a cause of, or a consequence of, hypertension-related changes in the vessel wall.…”

Section: Discussionsupporting

confidence: 52%

“…It will be important to find out at what stage during the development of hypertension the changes we describe occur. We have already shown that increased cerebrovascular sympathetic innervation precedes the onset of hypertension and associated medial hypertrophy which occurs after 5 weeks of age in SHR [18]. Indeed, neonatal or early sympathectomy has been shown to markedly reduce hypertension and in combination with α-adrenoceptor blockade, prevents the development of hypertension [19, 20].…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Neural Endothelin in Hypertension: Increased Expression in Ganglia and Nerves to Cerebral Arteries of the Spontaneously Hypertensive Rat

Milner

Loesch²,

Burnstock³

2000

J Vasc Res

View full text Add to dashboard Cite

Endothelin has previously been localised in perivascular nerves of the rat basilar artery. Considering its potent vasoconstrictor and mitogenic properties on vascular smooth muscle, the potential role of a neural source of this peptide in hypertension has been investigated. The trigeminal, superior cervical and sphenopalatine ganglia of Wistar Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) at 16 weeks of age have been examined for immunolocalisation of endothelin at the light and electron microscope level. At the light microscope level, neurones immunopositive for endothelin were detected in these ganglia of the SHR but were not seen in ganglia from WKY rats. This difference was particularly marked in the trigeminal ganglia where endothelin-positive neurones colocalised with substance P immunoreactivity. Using in situ hybridisation techniques, endothelin-1 mRNA was localised to the cytoplasm of neurones in the ganglia and was more prominent in the SHR. At the electron microscope level, endothelin-immunoreactivity was localised at the peripheral perikarya of some neuronal cell bodies of the trigeminal, superior cervical and sphenopalatine ganglia of WKY rats but was more prominent with heavy labelling throughout the cytoplasm of neurones in the SHR. Notably, in the trigeminal ganglia of the SHR only, some endothelin-immunopositive nerve fibres appeared to be damaged and contained vacuoles with granular material. Ultrastructural examination of the basilar artery revealed an increased number of endothelin-positive axons in the SHR, but these axons usually showed selective damage. In summary, in the SHR, there was a marked increase in endothelin particularly in sensory neurones projecting to the basilar artery which also appear to be undergoing degenerative changes. An increased neural source of endothelin in the SHR may contribute to the development of hypertension or may be a consequence of selective degenerative change.

show abstract

Section: Discussionsupporting

confidence: 52%

Section: Discussionmentioning

confidence: 99%

Neural Endothelin in Hypertension: Increased Expression in Ganglia and Nerves to Cerebral Arteries of the Spontaneously Hypertensive Rat

Milner

Loesch²,

Burnstock³

2000

J Vasc Res

View full text Add to dashboard Cite

show abstract

“…Overall, these data are consistent with the hypothesis that aging in the rat is normally accompanied by loss of some NPY-containing sympathetic neurons, which is absent from ganglia of the hypertensive strain. It is of interest that Dhital and colleagues 32 found that total NPY in superior cervical ganglia, as measured by radioimmunoassay, fell during maturation in normal Wistar rats but not in SHR. These workers did not detect any significant strain difference in ganglionic NPY at the end of that period, but it is not certain whether the normotensive rats used were from the Kyoto or another line, and therefore whether they represented an appropriate control for the SHR.…”

Section: Discussionmentioning

confidence: 99%

“…It has been reported that, in the SHR, the density of NPYI perivascular axons projecting from the superior cervical ganglion to the cerebral vasculature was considerably greater than in normotensive controls, despite the fact that the ganglionic content of NPY, as measured by radioimmunoassay, was similar for both strains. 32 Aging was associated with a decrease in NPY within individual neurons, as well as with decreased numbers of NPYI neurons. However, these two phenomena appear to have been independent, as the intensity of NPY staining decreased similarly in neurons of normal and of GH rats.…”

Section: Bar Graphs Showing Comparisons Of Size Distributions (Expresmentioning

confidence: 99%

Neuropeptide Y in rat sympathetic neurons is altered by genetic hypertension and by age.

et al. 1990

View full text Add to dashboard Cite

We have used immunocytochemistry to quantitate neuronai neuropeptide Y in superior cervical ganglia of a strain of nonnotensive Wistar-Otago rats and a related genetically hypertensive strain over the age range 1-60 weeks. The numbers of neuropeptide Y-immunoreactive cells and total ganglionic cell numbers were both greater in ganglia of young nonnotensive than in those of hypertensive rats. Between 10 and 60 weeks of age, peptide immunoreactivity and total cell numbers both fell in nonnotensive rat ganglia but remained constant in ganglia from hypertensive rats. Densitometric analysis showed that the concentrations of neuropeptide Y were similar in neurons of age-matched individuals of both strains, but during aging there was a substantial decline in neuronai peptide content that was similar in both strains and that was not accompanied by any decline in neuronai immunoreactivity for tyrosine hydroxylase. Our results suggest that there is a developmental abnormality of neuropeptide Y in sympathetic neurons of this strain of genetically hypertensive rat and that, furthermore, the aging process is accompanied by a selective loss of neuronai neuropeptide Y that is independent of blood pressure status. (Hypertension 1990;16:63-71) I n adult animals of both the Otago (GH) and the Kyoto (SHR) strains of rat with a hereditary predisposition to hypertension, there is biochemical and functional evidence that peripheral sympathetic activity is inappropriately high.1 -7 Furthermore, neonatal destruction of the peripheral sympathetic nervous system retards the development of hypertension and reduces the absolute extent to which both blood pressure elevation and the associated cardiovascular hypertrophy are seen in adulthood. 8 * 14Also, studies in the GH strain have shown that hypertension can be reversed completely by ganglion blocking agents until the rats are about 4 weeks of age. 15There are, therefore, several lines of evidence to suggest that elevated sympathetic drive may be an etiologic factor in the genesis of high blood pressure in these animal models for essential hypertension. In the sympathetic nervous system, neuropeptide tyrosine or neuropeptide Y (NPY) is jointly localized 23 Therefore, we compared the patterns of NPY immunoreactivity in sympathetic neurons of nonnotensive and GH hypertensive rats from the neonatal period through late adulthood. Methods AnimalsThe rats used in the present study were raised in our animal house from a normotensive white Wistar line originating in the Otago Medical School and from the GH line that was bred from the same stock.24 Breeding was from brother-sister matings, and ah 1 rats were fed a proprietary rat chow (quoted sodium content 0.5%) with water ad libitum. Periodic checks of blood pressures in conscious, prewarmed adult rats using an occlusive tail cuff and a pulse transducer confirmed that resting systolic pressures were less than 140 mm Hg in normotensive rats and at least 170 mm Hg in hypertensive rats.

show abstract

“…Sympathetic activity is increased in hypertensive animals and humans, and sympathoinhibition decreases blood pressure (4,15,23,24,29,40). Hypertension is also a complication of diabetes and obesity.…”

Section: Perspectives and Significancementioning

confidence: 99%

Kv1.3 channels in postganglionic sympathetic neurons: expression, function, and modulation

Doczi¹,

Morielli²,

Damon³

2008

American Journal of Physiology-Regulatory, Integrative and Comp

View full text Add to dashboard Cite

show abstract

Increased density of perivascular nerves to the major cerebral vessels of the spontaneously hypertensive rat: differential changes in noradrenaline and neuropeptide Y during development

Cited by 59 publications

References 69 publications

Neural Endothelin in Hypertension: Increased Expression in Ganglia and Nerves to Cerebral Arteries of the Spontaneously Hypertensive Rat

Neural Endothelin in Hypertension: Increased Expression in Ganglia and Nerves to Cerebral Arteries of the Spontaneously Hypertensive Rat

Neuropeptide Y in rat sympathetic neurons is altered by genetic hypertension and by age.

Kv1.3 channels in postganglionic sympathetic neurons: expression, function, and modulation

Contact Info

Product

Resources

About