+ Site Statistics
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Electrophysiological analysis of the nature of adrenoceptors in the rat basilar artery during development

British Journal of Pharmacology 86(1): 217-228

Electrophysiological analysis of the nature of adrenoceptors in the rat basilar artery during development

1 The nature of adrenoceptors in basilar arteries of neonatal rats was investigated by means of electrophysiological techniques. 2 In immature (2-6 day postnatal) rats, micro-injection of noradrenaline elicited a depolarization which consisted of two components. The initial 'fast' component (time to peak of 0.3-4 s) was slightly reduced by phentolamine and was not antagonized by propranolol. The second 'slow' component (time to peak of about 50 s) was not blocked by phentolamine but was antagonized by low concentrations (10-7 M) of propranolol. 3 In immature rats, micro-injection of isoprenaline was more potent than noradrenaline in evoking the 'slow' depolarization but less effective in eliciting the 'fast' response. The pharmacology with respect to adrenoceptor antagonists of both components of the isoprenaline- and noradrenaline-induced depolarizations was similar. There was some evidence of inhibitory .beta.-adrenoceptors in immature rat basilar vessels. 4 In adult rats (6 week old) noradrenaline produced a large 'fast' depolarization which was followed by a 'slow' tail response. Both components were not antagonized by phentolamine or propranolol. 5 It appears that in the basilar artery of neonatal rats there are excitatory .alpha.- and inhibitory .beta.-adrenoceptors but the major responses to noradrenaline and isoprenaline are mediated by .gamma.- and excitatory .beta.-receptors. In adult animals the .gamma.-adrenoceptor predominates. 6 Experiments were carried out in which agonists were applied by ionophoresis. These results confirm the presence of excitatory .beta.-receptors in neonatal basilar vessels and show the response has slow kinetics and it is likely that the .beta.-receptors are distributed uniformly over the smooth muscle surface. In adult animals it was not possible to elicit an excitatory .beta.-receptor-mediated response. 7 The ionophoretic application of noradrenaline never evoked a perceptible depolarization which could be attributed to .gamma.-adrenoceptor stimulation. This result is discussed in terms of receptor distribution with respect to synaptic function in a syncytium.

Accession: 005349407

PMID: 4052724

DOI: 10.1111/j.1476-5381.1985.tb09452.x

Download PDF Full Text: Electrophysiological analysis of the nature of adrenoceptors in the rat basilar artery during development

Related references

The nature of the adrenoceptors in the isolated rat basilar artery during development. Journal of Physiology (Cambridge) 365: 95P, 1985

Pharmacological characterization of the alpha adrenoceptors of the dog basilar artery. Naunyn-Schmiedeberg's Archives of Pharmacology 319(1): 1-7, 1982

Characterization of beta adrenoceptors in pig basilar artery from functional and radioligand binding studies. Japanese Journal of Pharmacology 59(SUPPL 1): 108P, 1992

Emergent basilar artery and bilateral posterior cerebral artery angioplasty, urokinase thrombolysis, and stenting for acute basilar artery occlusion secondary to diagnostic cardiac catheterization: case presentation. Journal of Neuroimaging 15(4): 315-318, 2005

Differential electrophysiological actions of endothelin-1 on Cl- and K+ currents in myocytes isolated from aorta, basilar and pulmonary artery. Journal of Pharmacology and Experimental Therapeutics 284(3): 1122-1131, 1998

The nature of adrenoceptors in the coronary artery of pigs. Journal of Molecular & Cellular Cardiology 12(SUPPL 1): 3, 1980

Subarachnoid hemorrhage and granulomatous angitis of the basilar artery demonstration of the varicella zoster virus in the basilar artery lesions. Stroke 17(5): 1024-1028, 1986

Outcomes of basilar artery occlusion in patients aged 75 years or older in the Basilar Artery International Cooperation Study. Journal of Neurology 259(11): 2341-2346, 2013

Extent of hypoattenuation on CT angiography source images in basilar artery occlusion: prognostic value in the Basilar Artery International Cooperation Study. Stroke 42(12): 3454-3459, 2012

Extracranial-intracranial arterial bypass and basilar artery ligation in the treatment of giant basilar artery aneurysms. Neurosurgery 13(2): 189-194, 1983