Sp. Altenburg et al., ADRENERGIC MODULATION OF THE BLOOD NEUTROPHILIA INDUCED BY PLATELET-ACTIVATING-FACTOR IN RATS, European journal of pharmacology, 256(1), 1994, pp. 45-49
The involvement of catecholamines in blood neutrophilia observed after
administration of platelet activating factor (PAF) to rats was studie
d. Intravenous (i.v.) injection of PAF (4 mu g/kg) into naive rats mor
e than doubled the number of neutrophils after 1 h. In contrast, PAF f
ailed to induce neutrophilia in both adrenalectomized rats and those w
hich had their catecholamine stores depleted by reserpine. PAF-induced
neutrophilia was not inhibited by the selective antagonism of alpha(1
)- and alpha(2)-adrenoceptors with prazosin and yohimbine, respectivel
y. However, pretreatment with the beta-adrenoceptor antagonist, propra
nolol, significantly inhibited the phenomenon. Increase in the blood n
eutrophil counts was also achieved following the i.v. injection of the
beta-agonist, salbutamol (1 mg/kg, i.v.). This response was clearly s
ensitive to propranolol but was not modified in rats submitted to adre
nalectomy or reserpine pretreatment. The results suggest that the bloo
d neutrophilia induced by the i.v. administration of PAF in rats is de
pendent on the stimulation of beta-adrenoceptors by catecholamines rel
eased from adrenal glands.