Example sentences for: kcna
How can you use “kcna” in a sentence? Here are some example sentences to help you improve your vocabulary:
Voltage-gated K +currents with distinct electrophysiological and pharmacological properties are present in granulosa cells (GC), and modulate resting membrane potential [ 4 12 13 16 17 ] . Furthermore, selective antagonism of GC K +channels with distinct molecular correlates, electrophysiological properties and expression patterns can influence differentially GC proliferation, steroidogenic capability, and apoptosis [ 17 18 ] . Our laboratory has previously identified two distinct delayed rectifier K +currents in pig GC: a slow current (I Ks ) associated with channels formed by co-assembly of KCNQ1 pore-forming and KCNE1 accessory proteins, and an ultra-rapid current (I Kur ) formed by co-assembly of KCNA pore-forming and KCNAB accessory proteins [ 4 ] . Moreover, we have shown that selective block of I Ks enhances basal progesterone synthesis, while complete block of both I Ks and I Kur accelerates apoptosis [ 18 ] .
Here, our goal was to determine the functional effects of antagonizing GC K +channels formed by KCNA vs.
Overall, these data are consistent with previous reports that endocrine cells express voltage-sensitive ion channels that can contribute to the regulation of not only resting membrane potential and cell volume, but also cell proliferation and steroidogenesis [ 12 13 16 18 21 28 29 30 31 32 33 34 35 36 37 ] . The K +currents blocked by 4-AP in pig GC are conducted by ion channels formed by heteromeric complexes of pore-forming subunits from the KCNA (also called Kv1 or Shaker) family of proteins and accessory subunits from the KCNAB (also called Kvβ) family of proteins [ 4 ] . Similar 4-AP-sensitive K +currents play a key role in transduction of mitogenic signals in a variety of cell types, and 4-AP treatment has been associated with not only growth arrest but also apoptosis [ 2 3 8 9 10 14 38 39 40 41 42 ] .
4-aminopyridine, at millimolar concentrations, completely inhibits K +currents conducted by heterologously expressed KCNA channels and native GC I Kur , but lacks significant effects on native GC I Ks [ 4 12 13 20 ] . Kusaka showed that antagonism of 4-AP sensitive slowly inactivating delayed rectifier K +currents suppressed both basal and luteinizing hormone (LH)-stimulated progesterone production [ 21 ] . In this report, we extend those findings by demonstrating 4-AP inhibition of follicle stimulating hormone (FSH)-stimulated progesterone production, and by elucidating the underlying mechanisms.
The K +channel subunits and currents modulated by estradiol in vascular and uterine smooth muscle differ from the 4-AP sensitive KCNA family channels that contribute to the 4-AP sensitive current I Kur in pig GC [ 4 49 50 52 53 ] . Moreover, in the single study where estradiol was shown to influence the gating of a uterine delayed rectifier current with electrophysiological characteristics resembling those of GC I Kur , the observed effect of the hormone was inhibitory [ 51 ] , and thereby similar rather than opposite to the effect of 4-AP.
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