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Biomedical subjects

M Lisa

Publications and source records attributed to M Lisa.

13 recordsLinked to original sources
PubMed1989

Injection of muscimol into posterior hypothalamus blocks stress-induced tachycardia.

We have previously shown that the physiological and behavioral manifestations of emotional stress are produced when drugs impairing gamma-aminobutyric acid (GABA)-mediated synaptic inhibition are injected into the posterior hypothalamic nucleus in rats [Wible, J.H., Jr., F.C. Luft, and J.A. DiMicco. Am. J. Physiol. 254 (Regulatory Integrative Comp. Physiol. 23): R680-R687, 1988]. The purpose of this study was to assess further the potential role of GABA receptors in this region in the response to stress using muscimol, a GABAA receptor agonist. In six chronically instrumented conscious rats, air stress after vehicle treatment evoked marked and sustained tachycardia (+130 +/- 14 beats/min at +10 min) accompanied by a less dramatic increase in arterial pressure (+14 +/- 3 mmHg). Microinjection of muscimol (10 ng; 88 pmol) at the same posterior hypothalamic site in which GABA blockade causes cardiovascular changes similar to those seen in stress produced a modest depression of cardiovascular function in unstressed animals (-28 +/- 5 beats/min and -6 +/- 3 mmHg). However, similar treatment with muscimol virtually abolished the stress-induced tachycardia in the same rats (+9 +/- 8 beats/min), while having no significant effect on baroreflex-evoked increases in heart rate caused by intravenous infusion of sodium nitroprusside (4 micrograms). These findings support a role for activation of neurons in the posterior nucleus of the hypothalamus in the generation of stress-induced cardiovascular changes and for control of this mechanism by local GABA receptors.

Animals↗
PubMed1989

Evidence of muscarinic receptor subtypes in airway smooth muscle of normal volunteers and of chronic obstructive pulmonary disease patients.

Since there have been only a few studies on muscarinic receptor subtypes in airway smooth muscle, the effect was investigated of pirenzepine on airways of patients with chronic obstructive pulmonary disease (COPD) and the functional responses compared from these patients with those from healthy subjects. Our data demonstrated that the therapy with pirenzepine significantly improved ventilatory function in patients with COPD. The data also suggested that this drug exerts its action on small airways, but not larger airways in normal subjects. It is possible that in healthy human beings pirenzepine produces mild bronchodilation by means of a vagal efferent blockade, while in patients with COPD, it may be effective because it not only decreases the activity of the vagal efferent pathway, but also decreases the sensitivity of vagal sensory endings and causes a vagal afferent blockade.

Atropine↗
PubMed1988

Prenatal and postnatal thallium exposure in rats: effect on development of vasomotor reactivity in pups.

Vasomotor reactivity has been evaluated in rats exposed perinatally and postnatally to thallium sulphate (1 mg/dl in their drinking water ad libitum). Prenatal and postnatal exposure to thallium did not modify the values of the systolic arterial blood pressure on the 30th and 60th day in pups of normotensive and DOCA-hypertensive rats. The hypertensive responses induced by endosinusal carotid hypotension and by 1-noradrenaline in pups of normotensive and DOCA-hypertensive rats, exposed or not exposed to thallium sulphate, were more intensive on the 60th than on the 30th day. Similar effects were observed for the hypotensive responses induced by 1-isoprenaline and acetylcholine. Prenatal exposure to thallium did not modify hypertensive responses induced by endosinusal carotid hypotension on the 30th and 60th days, but it caused a decrease of hypertensive responses induced by 1-noradrenaline on the 30th and 60th days and hypotensive responses induced by 1-isoprenaline and acetylcholine exclusively on the 60th day. Postnatal exposure to thallium did not modify hypertensive responses induced by endosinusal carotid hypotension and hypotensive responses induced by acetylcholine, but it caused a decrease of hypertensive responses induced by 1-noradrenaline on the 30th and 60th days in pups of normotensive rats and exclusively on the 60th day in pups of DOCA-hypertensive rats. Moreover, postnatal exposure to thallium caused a decrease of the hypotensive response induced by 1-isoprenaline exclusively on the 60th day. Our findings show that prenatal and postnatal exposure to thallium sulphate modifies the rat's developing vascular autonomic nervous system with a reduction of the alpha, beta-adrenergic and muscarinic vasomotor reactivity.

Animals↗
PubMed1988

Ureas and amides derived from N-(5-norbornen-2-ylmethyl) bornan-2-exo-amine with antiarrhythmic and other activities.

The synthesis of title compounds by reaction of camphor nitrimine with (5-norbornen-2-yl)methylamine, followed by NaBH4 reduction of the resulting imine to N-substituted isobornylamine (IV) and reaction of (IV) with alkyl and aryl isocyanates or acyl chlorides, is described. Some ureas and amides are endowed with antiarrhythmic activity in rats superior or comparable to that of quinidine, whereas benzamide (V o) showed an appreciable hypoglycemic activity in mice. Moreover, compounds (V) exhibited in general moderate hypotensive, bradycardic and antiinflammatory activities in rats, as well as a weak infiltration anesthesia in mice.

Amides↗
PubMed1987

N-acyl-N'-methyl-N-(1,3,3-trimethylbicyclo[2.2.1]hept-2-yl) benzamidines with hypotensive activity.

Lithium aluminium hydride reduction of N-phenoxycarbonyl-N,N-(1,3,3-trimethylbicyclo[2.2.1]-hept-2- yl)benzamidine (II), which afforded the N-acyl derivatives (III a-f) in good yields. Compounds (II) and (III) showed a moderate hypotensive activity in rats. Local anesthetic activity by infiltration in mice, effects on heart rate and antiarrhythmic activity in rats are also reported.

Amidines↗
PubMed1987

Esters of N-(2-hydroxy-1,1-dimethylethyl)-1,7,7-trimethylbicyclo[2.2.1] heptan-2-exo-amine with hypotensive activity.

The synthesis of title compounds by reaction of camphor nitrimine with 2-amino-2-methylpropanol, followed by NaBH4 reduction of the resulting imine to the aminoalcohol (III) and esterification of (III) with aliphatic and aromatic acyl chlorides in pyridine solution, is described. Phenyl carbamate (V) was also prepared by reaction of (III) with phenyl isocyanate. Some esters and (V) showed a moderate hypotensive activity in rats. Effects on heart rate and antiarrhythmic activity in rats, as well as infiltration anesthesia in mice, are also reported.

Amines↗