The effects of beta-blockers and diazepam on heart rate of conscious conditioned rats.
1. Fischer male rats were trained to avoid shock in a shuttle box. After this procedure, a small ECG transmitter was incorporated under the skin of thorax. 2. In saline group, when in the shuttle box heart rate significantly increased, and decreased while exposed to the buzzer. 3. When beta-blocker (carteolol, pindolol, propranolol) was injected, heart rate did not increase after the rat was put in the shuttle box, but decreased after exposed to the buzzer. Change in heart rate was not shown when diazepam was injected. 4. These results indicated that diazepam is more effective than beta-blocker in terms of instability of heart rate in conditioned rats.
Department of Psychiatry and Neurology, Hamamatsu University School of Medicine, Japan.
M
M
Nishimoto
T
T
Uematsu
T
T
Ozaki
H
H
Satoh
M
M
Nakashima
K
K
Miyasato
K
K
Ohara
K
K
Ohara
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D003213:Conditioning, Psychological / Q000502:physiology; D003975:Diazepam / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D013315:Stress, Psychological / Q000503:physiopathology*
D000319:Adrenergic beta-Antagonists; D003975:Diazepam