Hypoxia and high glucose activate tetrodotoxin-resistant Na(+) currents through PKA and PKC.

Voltage-gated sodium channels are critical for the initiation and propagation of action potentials and for the regulation of neuronal excitability. Hyperglycemia and hypoxia are two main changes in diabetes frequently associated with several complications. Although many studies on streptozotocin-induced diabetic rats indicate that early diabetic neuropathy is associated with increased amplitude and faster kinetics of sodium channels, the distinctive roles of high glucose and hypoxia have not been completely clarified.

Gonadotropin-releasing hormone inhibits ether-à-go-go-related gene K+ currents in mouse gonadotropes.

Secretion of LH from gonadotropes is initiated by a GnRH-induced increase in intracellular Ca(2+) concentration ([Ca(2+)](i)). This increase in [Ca(2+)](i) is the result of Ca(2+) release from intracellular stores and Ca(2+) influx through voltage-dependent Ca(2+) channels. Here we describe an ether-à-go-go-related gene (erg) K(+) current in primary mouse gonadotropes and its possible function in the control of Ca(2+) influx.

Functional characterization of genetically labeled gonadotropes.

Gonadotropes are crucial in the control of reproduction but difficult to isolate for functional analysis due to their scattered distribution in the anterior pituitary gland. We devised a binary genetic approach, and describe a new mouse model that allows visualization and manipulation of gonadotrope cells. Using gene targeting in embryonic stem cells, we generated mice in which Cre recombinase is coexpressed with the GnRH receptor, which is expressed in gonadotrope cells.