Studies on the Regulation of Secretion in Clara Cells with Evidence for Chemical Nonautonomic Mediation of the Secretory Response to Increased Ventilation in Rat Lungs
AUTOR(ES)
Massaro, Gloria D.
RESUMO
Using electron microscopy and morphometric methods to assess secretion, we previously found that two times tidal volume ventilation of isolated perfused rat lung stimulates secretion by bronchiolar Clara cells; this effect is not prevented by β-adrenergic blockade (J. Clin. Invest. 1981. 67: 345-351.). In this study we used the isolated perfused rat lung and the anesthetized mechanically ventilated rat, to further study the mechanism by which large tidal volumes stimulate secretion by Clara cells. With the perfused lung we found (a) α-adrenergic inhibition did not block the secretory effect of ventilation at two times normal tidal volume; (b) indomethacin completely blocked the secretory action of two times tidal volume ventilation; (c) medium previously used to perfuse lungs ventilated at two times tidal volume, but not medium previously used to ventilate lungs at normal tidal volume, stimulated secretion by Clara cells when used to perfuse fresh lungs ventilated at tidal volume; (d) addition of prostacyclin to the fresh perfusate increased secretion by Clara cells of lungs ventilated at normal tidal volume. In anesthetized mechanically ventilated rats, sighs stimulated secretion by Clara cells; this increased secretion was inhibited by indomethacin but not by cholinergic blockade (bilateral vagotomy). These studies indicate that increased volume ventilation stimulates secretion by Clara cells in vivo and in vitro; they provide evidence that chemical nonadrenergic, noncholinergic mechanisms are involved in this secretion, and that prostaglandins may be the chemical messenger coupling the mechanico-secretory events.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=370262Documentos Relacionados
- Regulation of secretion in Clara cells: studies using the isolated perfused rat lung.
- In vivo regulation of secretion of bronchiolar Clara cells in rats.
- Regulation of Bile Salt Transport in Rat Liver: EVIDENCE THAT INCREASED MAXIMUM BILE SALT SECRETORY CAPACITY IS DUE TO INCREASED CHOLIC ACID RECEPTORS
- Calcium mediation of the pig jejunal secretory response.
- Ultrastructural evidence concerning the mode of secretion of electron-dense granules by Clara cells.