• The Korean Journal of Pharmacology
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• v.32 no.1
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• pp.83-91
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• 1996

The present study was designed to determine the effect of hydrocortisone on CA secretion evoked by histamine from the isolated perfused rat adrenal glands. Histamine (150 ug) given into an adrenal vein produced significantly CA secretion from the rat adrenal medulla. This histamine-evoked CA secretion was enhanced markedly by the pretreatment with the natural glucocorticoid hydrocortisone (30 uM) or the synthetic glucocorticoid dexamethasone 30 (uM) for 20 min, respectively. Hydrocortisone-induced potentiation of CA secretion evoked by histamine was inhibited by preloading with heparin (3.56 U/ml), an $IP_3$ receptor antagonist while more enhanced by forskolin (0.2 uM), a potent stimulator of adenylate cyclase. From the experiment result taken together, it is thought that hydrocortisone (glucocorticoids) can enhance the releasing effect of CA evoked by histamine from the isolated perfused rat adrenal medulla, which seems to be associated to accumulation of inositol phosphate as well as cyclic AMP in the rat adrenomedullary chromaffin cells.

• Journal of Veterinary Clinics
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• v.27 no.2
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• pp.194-197
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• 2010

A 14-year-old gelded dressage horse weighing 500 kg was presented to the Equine Medical Center of the Seoul Racecourse of Korea Racing Authority (KRA) due to coughing and mucopurulent nasal discharge. The horse was initiated with empirical antibiotic in the first place. However, the clinical signs did not improve but were rather exacerbated even after 3 weeks of therapy. Extensive diagnostic procedures including transtracheal wash (TTW) fluid cytology were undertaken. The localized wheezes and crackles were auscultated and an increase in the amount of mucopurulent exudate in trachea was observed at endoscopy. Infiltration of neutrophils was observed in the TTW fluid cytology implying chronic obstructive pulmonary disease (COPD). Therefore, the systemic glucocorticoid therapy was to be given for 3 weeks with improved ventilation provided at the same time. The respiratory symptoms started to improve in 7 days of therapy and were fully resolved by when the therapy was terminated. The horse is clinically normal now and being monitored for development of any signs of chronic obstructive pulmonary disease.