Circ Shock. 1990 Dec;32(4):293-306.

Effects of canine endotoxin shock on lymphocytic beta-adrenergic receptors.

Circulatory shock

H J Silverman, N H Lee, E E el-Fakahany

PMID: 1963122

Abstract

To determine whether beta-adrenergic receptors on circulating lymphocytes are impaired during endotoxemia and the precise role of catecholamines in this process, we allocated 16 dogs to three groups: I) control-saline vehicle (n = 5), II) endotoxin--Escherichia coli endotoxin 1.0 mg/kg iv bolus (n = 6), and III) endotoxin + propranolol--E. coli endotoxin 1.0 mg/kg after pretreatment with propranolol, 1.5 mg/kg iv bolus followed by a continuous infusion, 30 micrograms/kg per min, (n = 5). Five hours after endotoxin injection, lymphocytic beta-adrenergic receptor number and sodium fluoride (NaF)-stimulated cyclic AMP accumulation were reduced by 41 +/- 6% and 25 +/- 7% of baseline values, respectively, which were significantly different from those observed in the control group (both P less than .01). Propranolol pretreatment prevented the endotoxin-induced reduction in lymphocytic beta-adrenergic receptor number (P less than .02 compared with the endotoxin group), but not the decrease in NaF-stimulated cyclic AMP accumulation (P less than .01 compared with the control group). Myocardial beta-adrenergic receptor number was reduced in the endotoxin group compared with that observed in the control group (P less than .06). These changes were associated with a decreased chronotropic response to isoproterenol in the endotoxin group compared with the control group (P less than .05). We conclude that decreased lymphocytic beta-adrenergic receptor number in endotoxin shock is caused by circulating catecholamines, whereas alterations distal to the receptors may be due to other mechanisms.

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Substances

• Endotoxins
• Receptors, Adrenergic, beta
• endotoxin, Escherichia coli
• Propranolol
• Cyclic AMP

MeSH terms

• Animals
• Cyclic AMP / metabolism
• Dogs
• Endotoxins / toxicity
• Lymphocytes / drug effects
• Lymphocytes / metabolism
• Propranolol / pharmacology
• Receptors, Adrenergic, beta / drug effects
• Receptors, Adrenergic, beta / metabolism
• Shock, Septic / metabolism
• Toxemia / metabolism

Publication Types

• Journal Article