Influence of the intravenous administration of ACTH-(1-24) on the characteristics of brain, heart and spleen adrenoceptors of haemorrhage-shocked rats.
Urethane-anesthetized rats were bled to otherwise irreversible haemorrhagic shock (mean arterial pressure = 18-25 mmHg) and then i.v. treated with ACTH-(1-24) (160 micrograms/kg) or saline. In comparison with sham-operated, non-shocked controls, bled rats showed a significant reduction in Bmax for [3H]Dihydroalprenolol and [3H]Dihydroergocryptine in heart ventricles, and for [3H]Yohimbine in spleen capsule. Neither the Kd of heart and spleen adrenoceptors nor the Bmax or Kd of brain adrenoceptors were affected. Treatment with ACTH-(1-24) restored to normal the Bmax for [3H]Dihydroalprenolol in heart ventricles, and for [3H]Yohimbine in the spleen capsule. These data indicate that the anti-shock effect of ACTH-(1-24) in bled rats is associated with a restoration of heart and spleen responsiveness to adrenergic stimuli.
Sandrini
M
M
Institute of Pharmacology, University of Modena, Italy.
Guarini
S
S
Bertolini
A
A
D000818:Animals; D001921:Brain / Q000187:drug effects*; D003366:Cosyntropin / Q000008:administration & dosage / Q000494:pharmacology*; D004082:Dihydroalprenolol / Q000378:metabolism; D006321:Heart / Q000187:drug effects*; D007275:Injections, Intravenous; D007700:Kinetics; D009206:Myocardium / Q000378:metabolism; D051381:Rats; D011941:Receptors, Adrenergic / Q000378:metabolism*; D012771:Shock, Hemorrhagic / Q000378:metabolism*; D013154:Spleen / Q000187:drug effects*
D011941:Receptors, Adrenergic; D003366:Cosyntropin; D004082:Dihydroalprenolol