PMID- 10716538
OWN - NLM
STAT- MEDLINE
DCOM- 20000515
LR  - 20190712
IS  - 0031-9384 (Print)
IS  - 0031-9384 (Linking)
VI  - 68
IP  - 3
DP  - 2000 Jan
TI  - Involvement of central beta-adrenoceptors in the tachycardia induced by water 
      immersion stress in rats.
PG  - 291-7
AB  - The purpose of the present study was to investigate whether central 
      beta-adrenoceptors are involved in stress-induced cardiovascular responses in 
      rats. Using a biotelemetry system, blood pressure and heart rate were measured at 
      rest and during stress induced by immersion in 1 cm-deep water. 
      Intracerebroventricular (i.c.v.) injections of a nonselective beta-adrenoceptor 
      antagonist, DL-propranolol (5 or 50 microg), significantly and dose dependently 
      attenuated the tachycardia induced by water immersion stress (drug-induced 
      reduction of tachycardia at 5 min after the start of stress: 61.4 +/- 13.2% for 5 
      microg, 72.5 +/- 8.2% for 50 microg). The same doses of DL-propranolol had no 
      effect on the resting heart rate. Injection (i.c.v.) of a lower dose (5 microg) 
      of D-propranolol--which has a lower potency as a beta-adrenoceptor antagonist 
      than DL-propranolol, but a similar local anesthetic, membrane-stabilizing 
      activity--did not attenuate the stress-induced tachycardia, although a higher 
      dose (50 microg) did. Intravenous administration of DL-propranolol (5 or 50 
      microg) significantly attenuated the stress-induced tachycardia (drug-induced 
      reduction of tachycardia at 5 min after the start of stress: 20.0 +/- 7.5% for 5 
      microg, 42.4 +/- 3.4% for 50 microg). However, the attenuation was much smaller 
      than in the i.c.v. DL-propranolol-injected group. The i.c.v. injection of the 50 
      microg dose of DL-propranolol significantly augmented both the resting blood 
      pressure and the pressor response to water immersion stress, whereas the lower 
      dose (5 microg) had no effect. The i.c.v. injection of 50 microg D-propranolol 
      also augmented, although not significantly, the resting blood pressure and the 
      pressor response to stress. These results suggest that central beta-adrenoceptors 
      are involved in the tachycardia induced by water immersion stress in rats.
FAU - Tan, N
AU  - Tan N
AD  - Department of Exercise and Health Science, Faculty of Education, Yamaguchi 
      University, Japan. tan@po.cc.yamaguchi-u.ac.jp
FAU - Morimoto, A
AU  - Morimoto A
FAU - Morimoto, K
AU  - Morimoto K
FAU - Sone, R
AU  - Sone R
FAU - Nishiyasu, T
AU  - Nishiyasu T
FAU - Watanabe, T
AU  - Watanabe T
FAU - Nakamura, S
AU  - Nakamura S
FAU - Murakami, N
AU  - Murakami N
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Physiol Behav
JT  - Physiology & behavior
JID - 0151504
RN  - 0 (Adrenergic beta-Antagonists)
RN  - 0 (Receptors, Adrenergic, beta)
RN  - 9Y8NXQ24VQ (Propranolol)
SB  - IM
MH  - Adrenergic beta-Antagonists/pharmacology
MH  - Animals
MH  - Arousal/drug effects/*physiology
MH  - Blood Pressure/drug effects/physiology
MH  - Brain/drug effects/*physiology
MH  - Dose-Response Relationship, Drug
MH  - Fear/drug effects/*physiology
MH  - Heart Rate/drug effects/*physiology
MH  - Immersion/physiopathology
MH  - Male
MH  - Propranolol/pharmacology
MH  - Rats
MH  - Rats, Wistar
MH  - Receptors, Adrenergic, beta/drug effects/*physiology
EDAT- 2000/03/15 09:00
MHDA- 2000/05/20 09:00
CRDT- 2000/03/15 09:00
PHST- 2000/03/15 09:00 [pubmed]
PHST- 2000/05/20 09:00 [medline]
PHST- 2000/03/15 09:00 [entrez]
AID - S0031-9384(99)00174-2 [pii]
AID - 10.1016/s0031-9384(99)00174-2 [doi]
PST - ppublish
SO  - Physiol Behav. 2000 Jan;68(3):291-7. doi: 10.1016/s0031-9384(99)00174-2.