TY - JOUR
T1 - Stimulated fluid secretion is sodium dependent in the Malpighian tubules of Locusta migratoria
AU - Morgan, P. J.
AU - Mordue, W.
PY - 1981/1/1
Y1 - 1981/1/1
N2 - The ionic dependencies of stimulated and unstimulated Locusta tubules have been studied. K+, Na+, Cl- are essential to both basal and stimulated secretion. K+ is secreted against a concentration gradient in unstimulated tubules. In response to diuretic hormone or cAMP application, there is a dramatic influx of K+ into the lumen. A high level of Na+ and Cl- in the bathing medium is required to allow maximal fluid secretion. The tubules show an apparent impermeability to Na+; its concentration in the secreted fluid is always much less than in the bathing medium. If Na+ is omitted from the medium and excess K+ added (80 mM K), then although basal secretion occurs (2.5 nl/min), the tubules fail to respond to stimulation. Clearly Na+ has an important indirect role to play in stimulated fluid secretion.
AB - The ionic dependencies of stimulated and unstimulated Locusta tubules have been studied. K+, Na+, Cl- are essential to both basal and stimulated secretion. K+ is secreted against a concentration gradient in unstimulated tubules. In response to diuretic hormone or cAMP application, there is a dramatic influx of K+ into the lumen. A high level of Na+ and Cl- in the bathing medium is required to allow maximal fluid secretion. The tubules show an apparent impermeability to Na+; its concentration in the secreted fluid is always much less than in the bathing medium. If Na+ is omitted from the medium and excess K+ added (80 mM K), then although basal secretion occurs (2.5 nl/min), the tubules fail to respond to stimulation. Clearly Na+ has an important indirect role to play in stimulated fluid secretion.
UR - http://www.scopus.com/inward/record.url?scp=0001829472&partnerID=8YFLogxK
U2 - 10.1016/0022-1910(81)90061-5
DO - 10.1016/0022-1910(81)90061-5
M3 - Article
AN - SCOPUS:0001829472
SN - 0022-1910
VL - 27
SP - 271
EP - 279
JO - Journal of Insect Physiology
JF - Journal of Insect Physiology
IS - 4
ER -