Sodium and asthma: something borrowed, something new?

Abstract

Some early studies have called attention to the potential contribution of sodium (both dietary and serum levels) in airway-related disease, although the picture was not entirely clear. Two recent developments may now allow a more careful consideration of this: first, the greatly improved understanding of the role of salt in hypertension (particularly the identification of subgroups of salt-sensitive individuals within the general population), and second, the recent discovery of the role of the Na(+)/Ca(2+) exchanger in smooth muscle function. Here, we first review those two developments and then apply them to airway smooth muscle and asthma.

Levels of serum lithium in manic depressive patients with mild persistent bronchial asthma

“…12 Thus, the inhibition of the Na/K pump, which appears to be associated with atopy, may contribute to airway dysfunction by elevating cytosolic levels of sodium, thereby promoting Ca2+ influx via reverse-mode NCX activity and increasing tone. 13 Potassium also plays an important role in ASM. ASM cells express various types of potassium (K+) channels which play a key role in determining the resting membrane potential, a relative electrical stability and the responsiveness to both contractile and relaxant agents.…”

Acción de la simvastatina en la contracción de músculo liso de anillo traqueal inducida por estímulo químico y térmico

“…Se ha señalado recientemente el papel de la proteína quinasa C (PKC) sobre la contracción de la tráquea a bajas temperaturas, y se ha involucrado en los efectos de este estímulo la activación de la PKC [17,18], ya que a bajas temperaturas se activa la vía de la lipooxigenasa, lo que trae como resultado una respuesta fisiológica de las vías aéreas con la disminución del diámetro bronquial. Recientemente se ha descubierto el papel de una bomba sodiocalcio que pudiera tener participación en el efecto del frío sobre el músculo bronquial [19]. Al incubar con simvastatina y estimular con agua fría, se encontró en estos resultados que este fármaco no inhibe la contracción que se produce por agua fría.…”

Asthma therapy: how far have we come, why did we fail and where should we go next?

“…Important advances have been made in the current understanding of the mechanisms underlying these Ca 2+ oscillations. These have been described in far greater detail than is possible here [36,37,40,41], and the biophysical and pharmacological properties of the cellular machines (pumps and channels) involved in triggering and propagating these Ca 2+ waves have been reviewed elsewhere [42,43]. The present study simply introduces the various cellular entities which are involved.…”