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PubMed1988

The influence of sympathomimetic and sympatholytic agents on the salivary flow rate and concentration of Ca, P and protein in the parotid gland of the goat.

1. The role of the sympathetic autonomic division on the parotid gland of normal and thyroparathyroidectomized (t.x.p.t.x.) goats was studied. 2. The salivary flow rate and concentration of Ca, P and protein was tested during the intravenous infusions of sympathomimetic and sympatholytic agents. 3. The intravenous infusion of isoprenaline modified the salivary flow rate and the concentration of total protein. 4. None of the tested drugs modified significantly the concentration of Ca and P in the parotid saliva. 5. The results obtained in normal and t.x.p.t.x animals were similar; it seems that PTH is not involved in the observed changes.

Animals↗
PubMed1988

Some in vitro effects of moclobemide and other MAO inhibitors on responses to sympathomimetic amines.

The use of inhibitors of monoamine oxidase (MAO) in the treatment of some forms of depression has been marred by the occurrence of unpleasant or even fatal side effects. Of these the most serious has been the risk of sudden hypertensive crises following the ingestion of food or drink containing indirectly-acting sympathomimetic amines such as tyramine (cheese effect). This effect, due to long lasting or irreversible inhibition of MAO in the gut and vasomotor neurones is much less obvious with the new generation of reversible inhibitors. Acceptance into clinical practice of these agents will depend upon the provision of clear and unequivocal evidence that there is little or no risk of unexpected cheese effects. The use of in vitro methods has provided a most sensitive way of revealing and measuring any such propensity in these new agents including moclobemide, cimoxatone and toloxatone. Use of isolated smooth muscles, such as the vas deferens and anococcygeus muscles of the rat together with vascular smooth muscle, typified by the perfused mesenteric arterial bed may be used as reliable preliminaries to in vivo and human volunteer studies in an attempt to introduce into clinical medicine an antidepressant that acts through the inhibition of MAO but carries little or no risk of the cheese effect.

Animals↗
PubMed1985

[Cardiocirculatory effects of a new sympathomimetic, amezinium methyl sulfate. Results of human pharmacological studies].

Changes in haemodynamic, inotropic state, and myocardial oxygen consumption were investigated in a total of eight patients with coronary artery disease after intravenous injection of 0.07 mg/kg amezinium methyl sulfate (LU 1631, Supratonin). It was demonstrated, that the principal effects of amezinium are consistent with those of a sympathomimetic agent which stimulates vascular alpha- and beta 1-adrenoreceptors. Amezinium (0.07 mg/kg) increased cardiac index, mean arterial pressure and total systemic resistance and dp/dtmax, while there were only minor changes in stroke index, mean pulmonary pressure and total pulmonary vascular resistance. In accordance with the changes in haemodynamics there was a 21.5% increase in myocardial oxygen consumption. But there were no signs of imbalance between oxygen supply and oxygen demand.

Adult↗
PubMed1977

[Sympathomimetic and sympatholytic drugs in the therapy of glaucoma (author's transl)].

The basis of sympathetic impulse transmission are summarised. Sympathomimetics and sympatholytics are discussed with regard to their mode of action, clinical use and contra-indications. We found that a 1% solution of adrenaline twice a day together with miotics is most suitable for long-term treatment. With the beta-blockers Bupranolol and Timolol tried by us can a massive pressure reduction be obtained, but which is of short duration with the concentrations used up till now. Adrenergic potentiators can not be recommended.

Albuterol↗
PubMed1984

Mechanisms of cardiac supersensitivity to sympathomimetic amines.

Supersensitivity of the beta-adrenoceptor-mediated positive inotropic and chronotropic responses of the heart to sympathomimetic amines is considered. The various types of supersensitivity of both pre- and post-synaptic origins are described and the possible mechanisms involved are discussed. Emphasis is given to the supersensitivity that arises from depletion of sympathetic catecholamine stores by reserpine and 6-hydroxydopamine. Results are presented which indicate that in both cases the supersensitivity develops slowly, is specific for the beta-adrenoceptor and is not associated with an increase in affinity of agonists for the receptor. Radioligand binding data is presented to show that there is no increase in the total number of beta-adrenoceptor binding sites in membrane fractions from ventricular homogenates of animals receiving reserpine. A review of the literature on binding studies indicates two opposing views with respect to the effects of reserpine on beta-adrenoceptor binding sites, one showing no change and the other showing an increase in total binding sites. Limited studies in the literature show that 6-hydroxydopamine may increase the number of sites. Binding data therefore remains inconclusive and must be interpreted with caution. The relationship between the development of depletion-induced supersensitivity and the innervation of the tissue and its receptor type is discussed.

Animals↗
PubMed1983

Central hemodynamics of beta-adrenoceptor blocking drugs: beta 1 selectivity versus intrinsic sympathomimetic activity.

It was the purpose of the present study to assess the hemodynamic effects of adrenergic beta-receptor blocking drugs possessing intrinsic sympathomimetic activity (ISA) and/or beta 1 selectivity, both at rest and during exercise. The hemodynamic effects of seven different beta-blockers (propranolol, atenolol, acebutolol, ICI 72,222, ICI 89,406, and pindolol) were studied at rest in patients with ischemic heart disease. Heart rate (HR), cardiac output (CO), arterial blood pressure (BP), and pulmonary artery pressure (PP) were determined. At rest, it was possible to subdivide the various beta-blockers into three main groups according to the degree of ISA. One group without ISA, including propranolol and atenolol, reduced CO by 25% and HR by 15%. A second group with moderate ISA, represented by practolol, acebutolol and ICI 72,222, reduced CO only by 15% and HR by 10%. A third group with pronounced ISA, represented by pindolol and ICI 89,406, did not change CO and HR significantly. All three groups consisted of drugs both with and without beta 1 selectivity. During exercise, pindolol and propranolol reduced CO, HR, and BP to the same extent. In conclusion, the central hemodynamic response to beta-blockers at rest is determined by the degree of ISA, whereas beta 1 selectivity does not modify the central hemodynamic response to beta-blockade. However, the hemodynamic differences between adrenergic beta-blocking drugs with and without ISA disappear in situations with increased sympathetic drive, such as exercise.

Adrenergic beta-Antagonists↗
PubMed1981

Effect of sympathomimetic substances and analogues on tail absorption of frog larva.

Similarly to the effect of T3, the tail absorption of frog larvae (Rana arvalis) was stimulated in vitro by the sympathomimetic agents adrenaline, isoproterenol, ephedrine and the adrenaline analogue MMT. The effect of T3 administration was not inhibited by adrenaline, isoproterenol and MMT, but it was by ephedrine and T3 pretreatment. The adrenaline and isoproterenol effect manifested itself after early administration, but not after late and while ephedrine and MMT were effective at long-term administration, even it administered at a later time. Our experiments draw attention to the metamorphotic effect of substances capable of binding to beta-receptors. Their effect may be explained partly by the increase in the cAMP level, partly by a relationship existing between the beta-receptor and the T3 receptor.

Animals↗
PubMed1983

The sympathomimetic activity of N-isopropyloctopamine in vitro.

Isolated right and left guinea-pig atria, guinea-pig tracheae and rabbit aortic strips were used to define the sympathomimetic properties of N-isopropyloctopamine. This compound was a highly beta selective, direct-acting adrenergic agonist, approximately 200- and 440-fold less potent than isoproterenol in cardiac and smooth muscle, respectively. It was nearly a full agonist in both cardiac and smooth muscle without appreciable selectivity for either beta-1 or beta-2 receptors and had no demonstrable beta blocking activity. No alpha adrenergic activity was detectable within the concentration range tested. The chronotropic effect of N-isopropyloctopamine was very persistent and resistant to repeated washing of the tissues, which may reflect unusually firm binding to beta receptors.

Animals↗
PubMed1984

[Therapeutic use of amezinium methylsulfate--a new, long acting, sympathomimetic--in paraspinal conduction anesthesia].

Cardiovascular effects of the new sympathomimetic ameziniummetilsulphate were investigated in 25 patients compared with a control group (n = 25). During spinal/epidural anaesthesia 5 mg amezinium was given i.v. if blood pressure dropped greater than 20 mmHg. from starting-point. A significant recovery of blood pressure (epidural anaesthesia: syst 21%, diast 9%; spinal anaesthesia: syst 13%, diast 6.6%) and a decrease in heart rate (6.8% resp. 4,5%) were thought due to peripheral vasoconstriction. Amezinium proved a stimulating drug for alpha- and beta 1-receptors by stabilising the systemic blood pressure in spinal/epidural anaesthesia.

Anesthesia, Epidural↗
PubMed1983

Effect of repeated treatments with sympathomimetic drugs on planarian glucose metabolism.

In response to sympathomimetic drugs (epinephrine, dopamine, isoproterenol, ephedrine), glucose utilization was enhanced in planarians. Upon repeated treatment with test substances one week after the first exposure the rate of glucose utilization differed from that observed at the first exposure. Under such conditions the responses appeared to vary depending on which of the drugs was used at the first exposure. After the elapse of two additional weeks the phenomenon (memory) was not further increased but the responses still differed from those recorded at the first exposure or two weeks after a single exposure.

Animals↗
PubMedDate not supplied

Hemodynamic effects of long term feeding of sympathomimetic amines to swine.

The hemodynamic effects of long term feeding of sympathomimetic amines (SPMA) to swine were studied. Three groups of female swine (N = 20 for each group) were fed either aminorex fumarate, d-amphetamine sulfate, or dextrose (control) for as long as 8 months in dosages up to 15 mg/kg/day. After 4 months of this feeding regiment, the weight gain of the pigs fed either aminorex or amphetamine was significantly less than the control animals. Hemodynamic measurements on awake swine indicated no elevation of pulmonary arterial blood pressure in the pigs fed SPMA. Measurement of systemic hemodynamics revealed that cardiac index was lower in the treated pigs than in control animals, but that heart rate and systemic arterial blood pressure were not altered by the drugs. In addition to baseline measurements of hemodynamic variables, the animals were exposed to acute hypoxia (12 percent O2 in N2) for 5 minutes. Although pulmonary arterial blood pressure increased similarly in the 3 groups of pigs, total pulmonary resistance increased to a greater extent in the pigs fed SPMA, indicating perhaps an enhancement of the hypoxic pulmonary pressor response after chronic ingestion of either amphetamine or aminorex. In a limited number of pigs, SPMA were fed for a period of 8 months, of which the last 3 months were during pregnancy. Hemodynamic measurements on sedated (metomidate, IV) swine revealed no difference in pulmonary arterial blood pressures between treated and control animals. We conclude that chronic ingestion of large doses of aminorex or amphetamine in swine does not lead to pulmonary arterial hypertension, but that slight reductions in cardiac output and subtle alterations in the pulmonary pressor response to acute hypoxia may occur.

Aminorex↗
PubMed1980

[Sympathomimetic component of dopamine renal action in water-saline depletion].

In 20 healthy subjects hydro-saline depletion was achieved by a 4-day natriuretic treatment associated with hypo-saline diet. Dopamine (DA) was infused in subpressor dose (.1 microgram . kg-1 . min-1) during sustained hypotonic polyuria induced by 5% glucose infusion. Four 15-min clearance periods were performed. DA was infused during the 2nd and the 3rd period. The effective renal plasma flow (RPF) as well as the glomerular filtration rate (GFR) were calculated by PAH and creatinine clearances, respectively. In our experimental conditions DA produced: a) an increase in the abnormally isoosmotic sodium reabsorption as % of sodium distal load; b) a decrease in both sodium and osmolar clearance; c) an early increase in free water clearance. RPF and GFR decreased not significantly. The present results indicate that DA in hydro-saline depletion helps to preserve the extracellular fluid volume in minimizing the salt and water loss associated with hypotonic polyuria. These effects on sodium excretion may be related to sympathomimetic properties acquired by DA in this experimental condition.

Creatinine↗
PubMed1978

[Conjunctival alterations by sympathomimetic drugs (author's transl)].

This is the report of two patients, who used eye drops containing adrenergic agents for a relatively long period of time because of conjunctival troubles. The eye drops contained phenylephrine or tetryzoline or naphazoline. As a consequence of the vasoconstriction, the treatment led to an epithelial xerosis in the region of the caruncula and of the neighbouring eyelid edges. The keratinisation resulted in a closure and disappearance of the puncta lacrimalia. Therefore, the application of vasoconstrictive eye drops for a longer period of time is discouraged. Moreover, eye drops with a low concentration of the sympathomimetic agent should be preferred.

Aged↗
PubMedDate not supplied

[Distribution of different groups of indirect sympathomimetics between aqueous and "fatty" phases].

Ionization constants were measured and distribution between the "fatty" and aqueous phases of the drugs (amphetamine, ephedrin, tyramine, methylphenidate, pipradrol), belonging to two groups of indirect sympathomimetics differing in the mechanism of their action, was studied. The lipophilic nature of the study compounds is shown to correlate with some pharmacological properties determining the difference in action produced by these drugs.

Chemical Phenomena↗
PubMed1979

[The antiexudative and anti-edematous action of sympathomimetics].

The anti-exudative and anti-edematous effects and the dose-effect relationship of a-sympathomimetics, especially of l-phenylephrine-HCl (PE), have been demonstrated using as model the rat pad-carrageenan edema and the histamine liberator test, the dosage being administered cutaneously, orally, and intraperitoneally. The beta-receptor activating compound bamethane sulfate was not effective when used on the same models. Evidence of percutaneous penetration of PE was provided both on isolated skin and in viro. PE, when injected intravenously or subcutaneously, produced a rise of blood pressure in experimental animals. When PE was administered orally and cutaneously, it did not, however, alter the blood pressure. The anti-inflammatory and anti-exudative effects remianed unchanged.

Animals↗
PubMed1976

Characteristics of responses of isolated human fallopian tube to transmural stimulation and to sympathomimetic amines.

The responses of circular and longitudinal muscle of human fallopian tube to transmural stimulation and sympathomimetic amines have been investigated. It was found that tissues from the earlier part of the menstrual cycle (i.e., estrogen dominant) were less responsive to all stimuli than those from the middle or late phase of the cycle. Although excitatory alpha responses of ampulla and isthmus could be observed, the predominant response of ampulla and isthmus, in all phases of the menstrual cycle, to (--)-noradrenaline and transmural stimulation was inhibition of spontaneous activity. The inhibitory response to transmural stimulation, was abolished by tetrodotoxin and guanethidine. The inhibitory responses to transmural stimulation and (--)-noradrenaline were reversed by propranolol. These findings show that the response of tissues to transmural stimulation resulted from release of noradrenaline from adrenergic nerves, and subsequent action on inhibitory beta adrenergic receptors.

Electric Stimulation↗
PubMed1998

[The effect of two beta-2 sympathomimetic bronchospasmolytics on the ratio of sialylated and sulfated glycoconjugates in goblet cell secretions of the tracheal epithelium].

Rabbits were made to inhale two different beta 2 sympathomimetic bronchospasmolytics-salbutamol in Ventolin and phenoterolhydrobromid in Berotec. Changes of secretion contents in tracheal goblet cells were evaluated by classical and lectin histochemistry 30 minutes after administration of drugs. When comparing with control rabbits Ventolin completely suppressed the secretion of neutral glycoconjugates for the benefit of acidic glycoconjugates and completely suppressed sialylation. The administration of Berotec suppressed neutral glycoconjugates, either, but the suppression of sialylation was uncomplete. Berotec was found a less damaging agent.

Albuterol↗