The effect of a glucocorticoid on olfactory response of isolated mouse olfactory cells.

Oral administration and nasal instillation of glucocorticoids are currently being conducted and are producing satisfactory results for the treatment of olfactory dysfunctions. However, there are still many unanswered questions about the actions of glucocorticoids on the olfactory cells. In the present study, the effects of glucocorticoids on the olfactory response in mouse olfactory cells were examined by measuring changes in the intracellular Ca2+ concentration. The olfactory cells isolated from the BALB/c female mouse mucosa were stained with a Fura-2/AM and the changes in the intracellular Ca2+ concentration were observed by using a fluorescent microscopic image processing device, ARGUS50. The cells were exposed to the following olfactory stimuli, 3-ethoxy-4-hydroxy-benzaldehyde, caprylic acid, nonanoic acid, phenethyl alcohol and n-amyl acetate. When 0.1 and 0.01% betamethasone was applied to the olfactory cells for short periods(1 or 3 minutes), no changes were observed. However, long-term(7 minutes) application of 0.1 and 0.01% (but not 0.001 and 0.0001%) betametathone significantly decreased intracellular Ca2+ concentration, which was increased by olfactory stimulation. The inhibitory effect of betamethasone on Ca2+ influx into olfactory cells was attenuated by pre-treatment olfactory cells with RU486, a glucocorticoid receptor antagonist.

[Vasodilatory action of FK 409 on bovine retinal arteries--analysis by a microvessel perfusion system].

PURPOSE: We investigated the vasodilatory action of FK 409 on bovine retinal arteries using a microvessel perfusion system in vitro. MATERIALS AND METHODS: Bovine retinal arteries were obtained from bovine eyes. The arteries, 3 mm long and 110 microns in diameter, were attached to the microvessel perfusion system. The arteries were perfused with Tyrode solution containing 10(-6) M U46619, followed by 10(-6) M U46619 and FK 409 (10(-3) M or 10(-4) M). We also perfused the arteries with carboxy-2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide. The inner diameter of the arteries was measured under a microscope and analyzed by computer. RESULTS: FK 409 prevented contraction of bovine retinal arteries induced by perfusion of 10(-6) M U46619 when the arteries were perfused with 10(-3) to 10(-4) M FK 409. Addition of 100 microM PTIO, an nitric oxide (NO)-specific extinction agent, into the mixture of U46619 and FK 409 hadan antagonistic effect on the contractive action of FK 409. CONCLUSION: These results suggest that FK 409 has a dilatational effect on bovine retinal arteries and that the dilatational action of FK 409 is possibly produced by NO.