Vasomotor responses in rats "intoxicated" with doxorubicin.

In rats intoxicated with doxorubicin, vasomotor responses were evaluated 12 hr after the last dosage. In rats pretreated with doxorubicin, hypertensive responses to L-norepinephrine and L-epinephrine, and hypertension by occlusion of both common carotid arteries were significantly (p < 0.05) reduced when compared with controls. Doxorubicin pretreatment also significantly reduced the arterial hypotension due to L-isoprenaline. In rats intoxicated with doxorubicin, pretreatment with L-sulpiride (12.5 to 50 mg/Kg/day for 30 days in drinking water ad libitum) did not modify the effects of doxorubicin on vasomotor reactivity. In contrast, pretreatment with amitriptyline (12.5 to 50 mg/Kg/day in drinking water ad libitum for 30 days) potentiated the inhibitory effects of doxorubicin on vasomotor responses. In conclusion, our research shows that doxorubicin intoxication induces a significant reduction of alpha- and beta-adrenergic reactivity and of baroreceptor activity.

omega-Dialkylaminoalkyl esters of N-phenyl aminethiocarboximidic acids with local anesthetic and other activities.

A series of omega-dialkylaminoalkyl esters of N-phenyl aminethiocarboximidic acids was prepared by reaction of N-phenyl 1-pyrrolidine, 1-piperidine, 4-morpholine, 1,2,3,4-tetrahydro-1-quinoline, 1,2,3,4-tetrahydro-2-isoquinoline, 10-phenothiazine, N-phenyl-2-pyridylamine and N-benzyl-2-pyridylamine-carbothioamides (prepared in situ from the appropriate secondary amine and phenyl isothiocyanate) with a number of omega-chloroalkyldialkylamines in anhydrous DMF or THF solution in the presence of sodium hydride. Good yields of the above esters were obtained provided that sodium hydride was added initially or after the formation of 3,3-disubstituted 1-phenylthiourea, according to the nature of the secondary amine. Some esters showed in mice local anesthetic activity comparable with that of lidocaine, as well as moderate hypoglycemic, antiarrhythmic, analgesic, antiacetylcholine, H1-antithistamine and platelet antiaggregating activities.

Teicoplanin does not modify the hypoglycemic effects of phenformin or glibenclamide, nor the anticoagulant action of warfarin. Experimental study.

Eventual pharmacological interactions induced by teicoplanin administration associated with oral hypoglycemic (phenformin and glibenclamide) and oral anticoagulant (warfarin) drugs have been experimentally evaluated. The administration of teicoplanin (3-15 mg/kg/die by endoperitoneal route) to the rat for 4 days did not significantly (P greater than 0.05) modify glycemia, prothrombin and partial thromboplastin times, the hypoglycemic effect of phenformin (2.5 mg/kg/die/4 days) or glibenclamide (0.5 mg/kg/die/4 days) nor the anticoagulant effect of warfarin (0.5 mg/kg/die/4 days). In conclusion, our results document that teicoplanin does not interfere with the activity of phenformin, glibenclamide or sodium warfarin.

Cardiovascular and respiratory effects of dermorphin in rats.

The cardiovascular and respiratory effects of dermorphin (D) have been evaluated in freely moving or anesthetized normotensive and spontaneously hypertensive male rats. Intravenously or intracerebroventricularly administration of D produced arterial hypotension with sinus bradycardia and respiratory depression. Naloxone antagonized the effects of D. Atrial natriuretic antipeptide IgG reduced the cardiovascular responses without any significant modification of respiratory response. ICI 174864, naloxonazine and binaltorphimine did not reduce the cardiovascular and respiratory effects. In hypertensive rats D produced more intense and longer cardiovascular effects than those seen in normotensive animals. D effects involve the activation of mu and k opioid receptors for cardiovascular responses and mu 2 opioid receptors for respiratory depression without any significant effect on delta receptors. The release of atrial natriuretic peptide also appears to be involved in the cardiovascular effects of D.

Milestoning: evoking memories for resocialization through group reminiscence.

An empirically conceived group reminiscence program was developed at a psychiatric center to evoke use of communication skills by geriatric residents. The goals were to tap into memories of a period before the patients' onset of dysfunctional mental illness and to prompt positive feelings during the guided discussions, thereby allowing for more frequent, appropriate interaction. Multisensory vivid imagery was employed to stimulate remembrances and increased communication.

Influence of rat prenatal and postnatal exposure to a non-steroidal anti-inflammatory agent (flunoxaprofen) on cardiovascular function in the progeny.

The present experiments evaluated in rats the effects of prenatal and postnatal exposure to a non-steroidal antiinflammatory agent, flunoxaprofen (5-10 and 20 mg/kg/day by the oral route), on cardiovascular function in the pups. In both conscious and anaesthetized rats pre- and postnatal flunoxaprofen exposure at the 30th and 60th day of age, significantly (P less than .05) induced a decrease of pressor response to carotid-sinus baroreceptor stimulation and to L-noradrenaline (0.1-1 and 5 micrograms/kg iv), and an increase of the hypotensive responses to L-isoprenaline (0.01-0.1 and 1 microgram/kg iv) and acetylcholine (0.01-0.1 and 1 microgram/kg iv). These effects were not observed in rats on the 90th day of age. Moreover, pre- and postnatal flunoxaprofen exposure did not modify systolic arterial blood pressure of plasma levels of catecholamines and acetylcholinesterases. Our results also show that in normotensive rats flunoxaprofen exposure during pregnancy did not affect the body weight, systolic or diastolic blood pressure or heart rate of pregnant rats. It did not affect the length of gestation, number of pups per litter or pup body weight. No macroscopic teratogenic effects were observed.

[Preparation and pharmacologic activity of N-oxides of 4'-(benzotriazol-2-yl-phenylalkanoic and -phenoxyalkanoic acids]. / Preparazione e attività farmacologica di n-ossidi di acidi 4'-(benzotriazol-2-il)-fenilalcanoici e-fenossialcanoici.

A number of N-oxides of 4'-(benzotriazol-2-yl)-phenylalkanoic and -phenoxyalkanoic acids bearing various substituents on position 6 of benzotriazole together with 4'-(benzotriazol-2-yl) phenylacetic acid were prepared and subjected to a wide pharmacological screening. Several compounds exhibited significant antiinflammatory and diuretic activities, while one was endowed with antihypertensive activity.

Pharmacodynamic profile of fenoverine, a novel modulator of smooth muscle motility.

Experimental research has documented that fenoverine is a depressant drug mostly active on the intestinal smooth muscle; however, it is also active on other tissues as well as on the genito-urinary tract. Fenoverine may be considered a synchronizer of smooth muscle effective in modulating the intracellular influx of calcium into the cell and its release from the intracellular pool. Fenoverine causes a reduction of the excitatory junction potential (EJP) in intestinal smooth muscle by stimulating parasympathetic efferent fibres without any change in the inhibitory junction potential (IJP). This also occurs in the presence of atropine. Fenoverine reduces the intracellular Ca2+ concentration by decreasing the calcium gradient across the cell membrane, as well as decreasing the release of Ca2+ from the intestinal pool more intensely than papaverine (but less intensely than nifedipine, verapamil or diltiazem). This phenomenon has been observed in the intestinal smooth muscle and also in the genito-urinary tract.

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.

Glutamergic transmission and cardiovascular apparatus in normotensive rats.

The cardiovascular effects induced by L-glutamic acid (G) on the cardiovascular apparatus of normotensive ethyl urethane-anaesthetized rats have been evaluated. (a) When administered i.v. (1 to 100 mg/kg) G induced a transitory and dose-dependent increase of arterial pressure (AP) with very moderate sinus bradycardia. It was antagonized by L-glutamic acid diethyl ester (GDEE, 0.1 to 100 mg/kg i.v.). (b) The intracerebroventricular (i.c.v.) administration of G (third ventricle, right lateral ventricle, posterior hypothalamus and striatum) at a dose of 0.1 to 10 mg/an induced a transitory and dose-dependent increase of AP, abolished by i.c.v. GDEE (1 to 10 mcg/an). (c) G hypertension was reduced by several procedures, i.e. catecholamine depletion, alpha 1, alpha 1 and alpha 2 or beta adrenergic blocks, alpha 2 central adrenergic stimulation, Ca2+ transmembrane or gangliary block, surrenectomy, and spinal transection at C7. (d) Atropine, bilateral vagotomy and sinus carotidal denervation increased G hypertension. (e) Therefore the bradycardia does seem to be due to a reflex-mediated effect via sinus carotid and aortic baroreceptors. (f) These data show that glutamergic transmission also participates through a central mechanism in the regulation of cardiovascular function in rats, via an increase in central sympathetic efferent activity.

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.

Participation of GABAergic mechanisms in the hypotensive and bradycardic effects of clonidine: experimental study in conscious normotensive and hypertensive rats.

In conscious rats with normal arterial blood pressure or with spontaneous or DOC induced hypertension, effects of drugs increasing (cycloserine, ethanolamine-o-sulphate, piracetam, chlordesmethyldiazepam) or depressing (bicuculline, Ro 15-1788, PK 11195) GABAergic reactivity were evaluated on the arterial hypotension and sinus bradycardia induced by clonidine. Clonidine was administered orally by gastric gavage (0.1-1 mg/kg). Pretreatment with cycloserine, ethanolamine-o-sulphate, piracetam or chlordesmethyldiazepam increased the hypotension and sinus bradycardia induced by clonidine. On the contrary, pretreatment with bicuculline or Ro 15-1788 reduced the cardiovascular effects of clonidine. These results suggest that the GABAergic system is involved in cardiovascular effects of clonidine in normotensive and hypertensive rats.

Aminoethers of (+)-1,3,3-trimethyl-2-oxabicyclo[2.2.2]-octan-6-hydroxyimine with hypotensive activity. II.

The synthesis of a series of N-substituted 3-amino-2-hydroxypropyl ethers (III a-1) starting from (+)-1,3,3-trimethyl-2-oxabicyclo [2.2.2]-octan-6-hydroxyimine is described. Some of these compounds showed a remarkable hypotensive and a weak bradycardic activity in rats, as well as a moderate local anesthetic activity in mice. All compounds were found to be devoid of antiarrhythmic activity in rats and of beta-blocking activity in dogs.

Derivatives of 1,2,3,3-tetramethyl-2-azabicyclo-[2.2.2]octan-5-trans-ol with antiarrhythmic and other activities. VI.

The synthesis of a series of alkyl and aryl amides (IV) starting from 5-trans-(3-aminopropoxy)-N-benzyl-1,2,3,3-tetramethyl-2-azabicyclo [2.2.2] octane is described. Some of compounds (IV) showed a moderate hypotensive activity in rats and infiltration anesthesia in mice. Effects on heart rate in rats and antiarrhythmic activity in mice were practically absent.

Derivatives of 1,3,3-trimethyl-6-azabicyclo-[3.2.1]octane with hypotensive activity. III.

The synthesis of a series of alkyl and aryl thioureas (II) starting from 1,3,3-trimethyl-6-azabicyclo[3.2.1]octane is described. Some of alkyl thioureas showed a moderate hypotensive activity in rats. Effects on heart rate and hypoglycemic activity in rats, infiltration anesthesia and antiarrhythmic activity in mice are also reported.