Characteristics of Potassium Channel in the Isolated Rat Detrusor Muscle / 영남의대학술지

The purpose of this study was to investigate the characteristics or the potassium channels existing in the rat urinary bladders. Smooth muscle strips of rat detrusor urinae were examined by isometric myography. Relaxation responses of detrusor muscle strips to the three potassium channel openers pinacidil, a cyanoguanidine derivative, BRL 38227, a benzopyran derivative and RP 52891, a tertrahydrothiopyran derivative were examined. The potassium channel openers reduced the basal tone, and the rank order of potency was RP 52891>pincidil>BRL 38227. Procaine, an inhibitor of the voltage-sensitive potassium channel tended to increase the basal tone, but it did not affect the relaxant effects of the calcium-activated potassium channel opener did not antagonize the relaxant effects, but it reduced the Emax of RP 52891 and BRL 38227. Glibenclamide, an inhibitor of the ATP-sensitive potassium channel, antagonized the relaxant effects of pinacidil, RP 52891 and BRL 38227 reducing the Emax of RP 52891 and BRl 38227. Galanin which inhibits secretion of insulin through opening the ATP-sensitive potassium channels in pancreatic β-cells rather increased the basal tone of the isolated detrusor strips. These results suggest that the urinary bladder of the rat has mainly the ATP-sensitive, glibenclamide sensitive potassium channel, which is a different type from that in the pancreatic β-islet cells.

A Case of the Inverted Papilloma with Verrucous Carcinoma of the Nose and Paranasal Sinuses / 영남의대학술지

Inverted Papilloma arising from mucous membrane of the nasal cavity and paranasal sinuses is rare benign neoplasm, and usually unilateral arise from lateral wall of nasal cavity. This tumor is histologically benign neoplasm but clinically malignant, because of frequent recurrence and extensive bone destruction. And occasionally, this tumor can be transformed to squamous cell carcinoma or verrucous carcinoma. Recently, we have experienced a case of the inverted papilloma with verrucous carcinoma of the nose and paranasal sinuses and patient expired due to extension of intracranial cavity. We report out case with review of current literatures.