Search results for "Clonidine"
showing 10 items of 33 documents
Alpha 2-receptor-mediated inhibition of intraluminal release of gastric somatostatin in anaesthetized rats.
1992
Alino, S. F., Garcia, D. & Uvnas-Moberg, K. 1992. Alpha2-receptor-mediated inhibition of intraluminal release of gastric somatostatin in anaesthetized rats. Acta Physiol Scand144, 233–238. Received 22 February 1991, accepted 11 October 1991. ISSN 00014772. Department of Pharmacology and Pharmaceutics, University of Valencia, Valencia, Spain, Department of Cell Biology and Morphology Science, University of Pais Vasco, Leioa, Spain and Department of Pharmacology, Karolinska Institute, Stockholm, Sweden. The aim of the present study was to investigate how the sympathetic nervous system affects the vagally induced intragastric release of somatostatin and gastrin. Experiments were performed on a…
Actions of alpha-adrenoceptor blocking agents on two types of intracellular calcium stores mobilized by noradrenaline in rat aorta.
1993
In isolated rat aortic strips noradrenaline induces a biphasic contractile response in Ca-free medium, associated with two different intracellular calcium pools, one of which is common to caffeine. We analyzed the mechanisms involved in the depletion and repletion of both intracellular Ca pools sensitive to noradrenaline in different experimental procedures in presence of prazosin, phentolamine and yohimbine. At 37 degrees C the alpha-adrenergic blocking agents inhibited contractile responses to noradrenaline in Ca-free medium, with prazosin being highly selective. alpha 2-adrenoceptors probably do not participate in the release of Ca from internal stores, as no contractile response was obs…
Intraoperative clonidine modulates sympathetic tone in the early postoperative period after remifentanil. A double blind, placebo-controlled study
1999
Abstract Aim of the study : Severe pain following major surgery can impair the control of the cardiovascular system (CVS) by causing sympathetic stimulation, possibly leading to myocardial ischaemia. In this study we examine the influence of intraoperative intravenous (i.v.) clonidine infusion on postoperative analgesia and blood concentrations of noradrenaline and adrenaline after major gynaecological surgery. Methods : All patients underwent an abdominal hysterectomy under balanced general anaesthesia using the new opioid remifentanil. The patients were randomised to receive either 5 μg kg −1 of i.v. clonidine intraoperatively ( n =20), or placebo ( n =20). Over a period of 240 minutes po…
Opioid poorly-responsive cancer pain. Part 3. Clinical strategies to improve opioid responsiveness.
2001
Some pain syndromes may be difficult to treat due to a poor response to opioids. This situation demands a range of alternative measures, including the use of adjuvant drugs with independent effects, such as antidepressants, sodium channel-blocking agents, steroids and anti-inflammatory drugs (NSAIDs); drugs that reduce opioid side effects; and drugs that enhance analgesia produced by opioids, such as N-methyl-D-aspartate (NMDA) antagonists, calcium channel antagonists, and clonidine. Other approaches, including opioid trials, neural blockade when necessary, and psychological interventions, also may be useful.
Szintigraphie adrenerger Tumoren mit 131J-meta-Benzylguanidin
2008
Pheochromocytoma scanning using 131J-meta-benzylguanidine was done in one patient with metastasizing paraganglioma, one patient with multiple endocrine neoplasia type IIb. No activity of tumour tissue could be demonstrated in the patient with metastasizing paraganglioma, whereas the pheochromocytoma could be clearly defined in the patient with multiple endocrine neoplasia type IIa. The female with multiple endocrine neoplasia type IIb showed a suspect space-occupying lesion of the left adrenal using computed tomography. Pheochromocytoma could be excluded by 131J-benzylguanidine scanning, selective estimation of catecholamines in adrenal venous blood as well as the glucagon stimulation and c…
Day-night differences in the sensitivity of adrenoceptors in the Syrian hamster pineal gland: an in vivo iontophoretic study.
1989
Abstract Investigations on the regulation of pineal melatonin synthesis in the Syrian hamster revealed distinct differences compared to this well-understood mechanism in rat. E.g., a circadian profile of pineal norepinephrine (NE) is absent, there is no β-adrenoceptor sensitivity during daytime and adrenergic receptor supersensitivity is not easily achieved. To elucidate the action of NE on pineal receptor sites, the effects of iontophoretic application of adrenergic compounds on spontaneous electrical discharge rates of pinealocytes were investigated during day- and nighttime. Following application of either NE, isoproterenol or clonidine, cells were activated, inhibited or not affected. W…
Spinal analgesia for advanced cancer patients: An update
2011
In the nineties, spinal analgesia has been described as an useful means to control pain in advanced cancer patients. The aim of this review was to update this information with a systematic analysis of studies performed in the last 10 years. 27 papers pertinent with the topic selected for review were collected according to selection criteria. Few studies added further information on spinal analgesia in last decade. Despite a lack of a clinical evidence, spinal analgesia with a combination of opioids, principally morphine, and local anesthetics may allow to achieve analgesia in patients who had been intensively treated unsuccessfully with different trials of opioids. Some adjuvant drugs such …
Risk of Periodontal Disease: Is there a Correlation with the Type of Antihypertensive Medication?
2011
Introduction: The purpose of this study was to evaluate the effects of long-term oral antihypertensive treatment using centrally acting sympatho-inhibitory drugs (clonidine) and beta-blockers (metoprolol) on capillary microcirculation in the labial and periodontal mucosa.
 Methods: Sixty subjects were recruited for the study: 20 patients affected by hypertension in treatment with centrally-acting sympatho-inhibitory drugs (64.28 ± 11.78 years); 20 patients in treatment with beta-blockers (62.03 ± 9.84 years) and 20 healthy subjects (62.06 ± 6.72 years). We use the videocapillaroscopic technique to evaluate in vivo the microcirculation of the labial mucosa corresponding to the lower lip…
Characteristics of histamine tachyphylaxis in rat uterine smooth muscle.
2002
Objective and design: To study both the desensitisation induced by short-term exposure to histamine and the mechanism responsible in the isolated rat uterus.¶Material: Precontracted isolated uterus (37 mM KCl) from oestrogenised Wistar rats were used.¶Treatment: Repetitive responses to histamine (10–6, 10–5, 10–4, 10–3 M), dimaprit and clonidine (10–4 M) were tested at 15, 30, 45 and 105 min., with their modifications by (5 mg/ kg, 24 h before sacrifice) reserpine, 10–7 M propranolol, 10–8 M atropine, and 10–6 M indomethacin. Dose-response curves for adrenaline were carried out as standard protocol.¶Methods: In vitro techniques (de Jalon's solution, 31°C, carbogen, isotonic registration, re…
Modulatory role of a constitutively active population of α1D-adrenoceptors in conductance arteries
2002
A constitutively active population of α1D-adrenoceptors in iliac and proximal, distal, and small mesenteric rat arteries was studied. The increase in resting tone (IRT) that evidences it was observed only in iliac and proximal mesenteric and was inhibited by prazosin (pIC50 = 9.57), 5-methylurapidil (pIC50 = 7.61), and BMY 7378 (pIC50 = 8.77). Chloroethylchlonidine (100 μmol/l) did not affect IRT, but when added before the other antagonists it blocked their effect. The potency shown by BMY 7378 confirms the α1D-subtype as responsible for IRT. BMY 7378 displayed greater inhibition of adrenergic responses in iliac (pIC50 = 7.57 ± 0.11) and proximal mesenteric arteries (pIC50 = 8.05 ± 0.2) th…