scholarly journals INTERACTIONS OF BETA-RECEPTOR BLOCKADE AND Pco 2 LEVELS IN THE ANAESTHETIZED DOG

1974 ◽  
Vol 46 (6) ◽  
pp. 397-404 ◽  
Author(s):  
P. FoËx ◽  
C. Prys-Roberts
Keyword(s):  
Receptor Blockade ◽  
Beta Receptor ◽  
Beta Receptor Blockade ◽  
Anaesthetized Dog

THE EFFECT OF BETA-RECEPTOR BLOCKADE ON EXERCISE AND ARGININE-INDUCED GROWTH HORMONE SECRETION IN MAN

1974 ◽  
Vol 77 (1_Suppl) ◽  
pp. S6 ◽  
Author(s):  
S. Raptis ◽  
H. Hirth-Schmidt ◽  
K. E. Schröder ◽  
E. F. Pfeiffer
Keyword(s):  
Growth Hormone ◽  
Hormone Secretion ◽  
Growth Hormone Secretion ◽  
Receptor Blockade ◽  
Beta Receptor ◽  
Beta Receptor Blockade

CATECHOLAMINE ANTAGONISM TO OXYTOCIN-INDUCED MILK-EJECTION

1971 ◽  
Vol 68 (1_Suppla) ◽  
pp. S5-S38 ◽  
Author(s):  
Helmuth Vorherr
Keyword(s):  
Receptor Blockade ◽  
Milk Ejection ◽  
Beta Adrenergic ◽  
Beta Receptor ◽  
Beta Receptors ◽  
Alpha Receptors ◽  
Adrenergic Blockers ◽  
Beta Receptor Blockade ◽  
Second Pain ◽  
Stimulation Of

ABSTRACT In lactating rats and rabbits the mode of antagonism of sympathomimetics, angiotensin or pain toward oxytocin-induced milk-ejection was investigated. In rats intra-arterial (intrafemoral) doses of 0.01–0.02 μg or intravenous (iv) doses of 0.1–0.5 μg of either epinephrine, isoproterenol, norepinephrine, angiotensin or 10 μg of phenylephrine injected simultaneously with, or 30 seconds before an oxytocin dose (10 μU intrafemoral, 300 μU iv) greatly inhibited or suppressed the oxytocin response. A 15 second pain stimulus caused moderate inhibition. With alpha-receptor blockade pain, epinephrine, isoproterenol, norepinephrine, phenylephrine and angiotensin inhibition were, respectively, 70%, 75%, 100%, 40%, 0% and 100%. Under beta-receptor blockade the corresponding values were 14%, 40%, 0%, 70%, 100% and 100%; with simultaneous intrafemoral injections neither catecholamine was inhibitory toward oxytocin. In corresponding rabbit experiments approximately 10-fold higher iv drug dosages were applied and similar results were observed. In both species, combined alpha and beta-receptor blockade nearly eliminated the antagonistic actions of sympathomimetics toward oxytocin, whereas angiotensin inhibition persisted unchanged. The results indicate: 1) Mammary myoepithelial cells contain beta-adrenergic receptors but no alpha-receptors; 2) Inhibition of oxytocin-induced milk-ejection by isoproterenol and phenylephrine is meditated through stimulation of myoepithelial beta-receptors (myoepithelial relaxation) and vascular alpha-receptors (vasoconstriction), respectively; 3) Epinephrine and norepinephrine inhibition of milk-ejection is due to stimulation of vascular alpha-receptors and myoepithelial beta-receptors; 4) Angiotensin effects are unrelated to adrenergic receptor mechanisms; 5) Administration of both alpha and beta-adrenergic blockers is desirable for stabilizing the sensitivity of the oxytocin milk-ejection assay preparation against interference from endogenous or exogenous catecholamines; 6) Other than using adrenergic blockers, pharmacologic doses of oxytocin can correct nursing difficulties in animals and man with hyperfunction of the adrenal-sympathetic system.

Effect of Beta-Receptor Blockade on Anxiety with Reference to the Three-Systems Model of Phobic Behavior

1985 ◽  
Vol 13 (4) ◽  
pp. 187-193 ◽  
Author(s):  
Olov Fagerström ◽  
Kenneth Hugdahl ◽  
Nils Lundström
Keyword(s):  
Receptor Blockade ◽  
Beta Receptor ◽  
Systems Model ◽  
Beta Receptor Blockade

Effects of central venous blood volume shifts on arterial baroreflex control of heart rate

1981 ◽  
Vol 241 (4) ◽  
pp. H571-H575 ◽  
Author(s):  
G. E. Billman ◽  
D. T. Dickey ◽  
K. K. Teoh ◽  
H. L. Stone
Keyword(s):  
Heart Rate ◽  
Blood Volume ◽  
Volume Expansion ◽  
Body Position ◽  
Venous Blood ◽  
Receptor Blockade ◽  
Baroreflex Control ◽  
Beta Receptor ◽  
Blood Volume Expansion ◽  
Beta Receptor Blockade

The purpose of this study was to investigate the effects of anesthesia, body position, and blood volume expansion on baroreflex control of heart rate. Five male rhesus monkeys (7.0-10.5 kg) were given bolus injection of 4.0 micrograms/kg phenylephrine during each of the following situations: awake sitting, anesthetized (AN) (10 mg/kg ketamine-HCl) sitting, AN recumbent, AN 90 degrees head down tilt, and AN 50% blood volume expansion with normal saline. beta-Receptor blockade was also performed on each treatment after anesthesia. Four additional animals were similarly treated after 20% blood volume expansion. R-R interval was plotted against systolic aortic pressure, and the slope was determined by linear regression. Baroreflex slope was significantly (P less than 0.05) reduced by 90 degrees head down tilt and 50% volume expansion both before and after beta-receptor blockade. A similar trend was seen after 20% volume expansion. These data are consistent with the thesis that baroreflex control of heart rate is reduced by central blood volume shifts.

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