Effect of atropine or atenolol on cardiovascular responses to novelty stress in freely-moving rats.

Abstract

Cardiac hemodynamic mechanisms involved in cardiovascular responses to stress were studied in conscious, freely-moving female spontaneously hypertensive rats exposed for 15 min to an open-field. When pretreated with saline, the rats displayed a rapid rise in blood pressure, heart rate, aortic dP/dt and locomotor activity. In rats pretreated with 0.5 mg/kg of methylatropine, the tachycardia was slightly, but significantly reduced. In rats pretreated with 1 mg/kg of atenolol, the tachycardis and rise in dP/dt were markedly reduced. These data suggest that the cardiac responses to stress include predominantly cardiac sympathetic activation and a minor component of vagal withdrawal.

• Authors: Maarten van den Buuse
• Journal: Stress (Amsterdam, Netherlands) (Stress) Vol. 5 Issue 3 Pg. 227-31 (Sep 2002) ISSN: 1025-3890 [Print] England
• PMID: 12186685 (Publication Type: Journal Article)

Chemical References

• Parasympatholytics
• Sympatholytics
• Atenolol
• Atropine

Topics

• Animals
• Atenolol (pharmacology)
• Atropine (pharmacology)
• Behavior, Animal (physiology)
• Blood Pressure (drug effects)
• Exploratory Behavior (physiology)
• Female
• Heart Rate (drug effects)
• Motor Activity (physiology)
• Parasympatholytics (pharmacology)
• Rats
• Rats, Inbred SHR
• Stress, Physiological (chemically induced, physiopathology)
• Sympathetic Nervous System (drug effects, physiopathology)
• Sympatholytics (pharmacology)
• Telemetry
• Vagus Nerve (drug effects, physiopathology)