Effects of azaperone on cardiovascular and respiratory functions in the horse.
(1/11)
1 The butyrophenone tranquilizer, azaperone, was administered intramuscularly, at dose levels of 0.4 and 0.8 mg/kg, to ponies and its effects on cardiovascular and respiratory functions assessed. 2 Arterial blood pH, CO2 tension (PaCO2) and O2 tension (PaO2) remained relatively constant throughout the course of action of azaperone. 3 Azaperone did not modify plasma protein concentration but venous blood packed cell volume and haemoglobin concentration were reduced by 5 to 10% for at least 4 hours. These changes were probably caused by uptake of erythrocytes into the splenic reservoir. 4 Small increases in heart rate occurred for up to 60 min after administration of the drug, and this was followed by a slight bradycardia in some ponies. 5 Azaperone reduced mean arterial blood pressure (MAP) for at least 4 h, by which time its ataractic action was generally no longer apparent. The hypotension was caused, during the early phase of action at least, by a reduction in peripheral resistance, since cardiac output was increased slightly 20 min after its administration. Possible mechanisms underlying the cardiovascular changes are discussed. 6 In spite of reductions in arterial blood O2 content and MAP produced by azaperone, it is likely that tissue oxygenation was adequate, since arterial blood lactate concentrations were not increased. (+info)
Responses of the pituitary-adrenal system of the pig to environmental changes and drugs.
(2/11)
1 The reactivity of the pituitary-adrenal axis of the young pig was tested for its suitability as a sensitive index for any discomfort that might be experienced under certain conditions of intensive husbandry.2 In a thermoneutral environment, most undisturbed piglets showed only slight variations in the plasma concentrations of adrenocorticotrophic hormone (ACTH) and corticosteroids.3 Stimuli such as exposure to ambient temperatures of +40 degrees C or -5 degrees C were required to cause large rises in the plasma concentrations of ACTH and corticosteroids.4 Apparently milder stimuli, such as change of environment, slight frustration or changes in ambient temperatures between +5 degrees C and +30 degrees C only rarely caused a significant rise in plasma corticosteroids. Thus changes in plasma corticosteroid concentrations are not a sensitive index for the reaction of a piglet to its environment.5 Increases in plasma ACTH concentrations occurred faster than those of the corticosteroids, were larger when expressed as a percentage of the basal values and occurred following relatively small disturbances such as omission of the reward in an operant behaviour test when corticosteroid changes were often not detectable. Thus rises in plasma ACTH might be a useful indication that a given situation is disturbing to a pig. The reaction of plasma ACTH concentrations to chronic irritations as they might occur in intensive husbandry remains to be investigated.6 Azaperone (2 mg/kg i.m.), a drug which is used as a sedative in pigs, caused a rise of about 50% in plasma corticosteroid concentrations. It did not diminish the large steroid output seen when the animals were exposed to high and low ambient temperatures. (+info)
Enhanced blood pressure and appetite responses to chronic central melanocortin-3/4 receptor blockade in dietary-induced obesity.
(3/11)
Influence of infused beta-adrenergic agonists on porcine blood metabolites and catecholamines.
(5/11)
Anesthetized pigs were infused sequentially with increased concentrations of beta-adrenergic agonists. At selected times during infusion, blood pressure, heart rate and plasma concentrations of free fatty acids (FFA), glycerol, glucose, lactate, norepinephrine, epinephrine and dopamine were measured. Azaperone, a drug used to calm the pigs before anesthesia, caused hypotension and bradycardia but did not affect plasma metabolites. Infusion of norepinephrine, epinephrine, isoproterenol or clenbuterol produced changes in plasma metabolites and plasma catecholamines. These changes during norepinephrine infusion were attributed to the infused agonist, whereas those during epinephrine infusion might have resulted to some extent from release of norepinephrine. Plasma isoproterenol was not quantified because it interfered with the assay of epinephrine and dopamine so that it was not possible to distinguish between infused isoproterenol and release of endogenous epinephrine and dopamine. Infusion of clenbuterol caused a small increase in plasma norepinephrine so that some of the increase in plasma FFA, glycerol and lactate during clenbuterol infusion may result from release of endogenous norepinephrine. (+info)
A behavioral pharmacological study of mafoprazine, a new phenylpiperazine derivative.
(6/11)
Behavioral pharmacological studies on mafoprazine, a new drug for the prevention of aggressive behavior, were performed to compare its effects with those of an existing drug, azaperone (Stresnil). The acute toxicity of mafoprazine in mice was slightly stronger than that of azaperone. Mafoprazine showed the following effects (at 0.2 to 2.0 mg/kg, s.c.): a decrease in spontaneous motor activity, prolongation of the duration of pentobarbital anesthesia, inhibition of long-term isolation-induced aggressive behavior, inhibition of olfactory bulbectomy-induced hyperemotionality and muricide behavior in mice and rats, and a marked taming and tranquilizing effect on aggressive behavior in dogs. These effects of mafoprazine were qualitatively the same as those of azaperone. Mafoprazine showed cataleptogenicity in rats at 5 mg/kg, s.c. or more and motor incoordination in rats at 0.2 mg/kg, s.c. or more. In the experiment on operant behavior in rats, the effect of mafoprazine on differential reinforcement of the low rate (DRL) response was almost the same as those of azaperone and chlorpromazine. These results indicate that mafoprazine has substantially the same psychotropic effect as azaperone, while the former has a weaker action on the extrapyramidal system than the latter, suggesting that mafoprazine could be used as a unique aggression-inhibiting drug. (+info)
Effects of amperozide and azaperone on aggression and productivity of growing-finishing pigs.
(7/11)
Levels of aggression, activity and performance were determined in 270 pigs (initial wt 29.8 kg) injected with amperozide (1.0 mg/kg i.m.), azaperone (2.2 mg/kg i.m.) or saline (.1 ml/kg i.m.) immediately prior to mixing. Pigs had ad libitum access to feed in pens of 15, and six pens were allotted to each treatment. Each pen was video-taped for 48 h after injection. Aggression was determined by continuous observation and summarized for each 2-h period. Injuries on the ears and shoulders of each pig were scored prior to injection and 1, 2, 3 and 7 d after treatment. Eating, drinking and lying were determined by scan sampling at 2-min intervals and summarized for each 2-h period. Weight gain, feed consumption and efficiency were determined for periods ending on d 3, 7, 14, 28, 42, 56, 70 and 84. Both drugs reduced total fighting from 309.8 min for saline to 190.7 and 189.6 min for amperozide- and azaperone-treated pens, respectively (P less than .01). Treatment differences in aggression and lying were evident during the initial 6 h only. Amperozide resulted in fewer fights involving two pigs (197.3/pen) than did azaperone (260.2/pen) or saline (298.3/pen) (P less than .05). Injuries to the ears (P less than .01) and total injuries (P less than .05) were less severe in amperozide-treated pigs than in pigs on the other treatments.(ABSTRACT TRUNCATED AT 250 WORDS) (+info)
An analysis of some behavioural effects of the vibration and noise components of transport in pigs.
(8/11)
The reactions of pigs to the vibration and noise components of transport were examined with the use of an apparatus which simulated these factors. The pigs were trained to switch off the apparatus by pressing a switch panel with their snouts. It was found that vibration was aversive but that noise was not. The pigs switched off the apparatus more frequently when the vibration was fast and when they had been fed a large meal before the test. Although the sedative tranquillizing drug azaperone decreased the number of times the apparatus was switched off, the effect appeared to be non-specific because azaperone also reduced the number of responses that pigs would make in order to receive food. (+info)