cAMP-mediated stabilization of fusion pores in cultured rat pituitary lactotrophs
Costa Calejo, Ana-Isabel ...
Regulated exocytosis mediates the release of hormones and transmitters. The last step of this process is represented by the merger between the vesicle and the plasma membranes, and the formation of a ...fusion pore. Once formed, the initially stable and narrow fusion pore may reversibly widen (transient exocytosis) or fully open (full-fusion exocytosis). Exocytosis is typically triggered by an elevation in cytosolic calcium activity. However, other second messengers, such as cAMP, have been reported to modulate secretion. The way in which cAMP influences the transitions between different fusion pore states remains unclear. Here, hormone release studies show that prolactin release from isolated rat lactotrophs stimulated by forskolin, an activator of adenylyl cyclases, and by membrane-permeable cAMP analog (dbcAMP), exhibit a biphasic concentration dependency. Although at lower concentrations (2-10 m forskolin and 2.5-5 mm dbcAMP) these agents stimulate prolactin release, an inhibition is measured at higher concentrations (50 m forskolin and 10-15 mm dbcAMP). By using high-resolution capacitance (Cm) measurements, we recorded discrete increases in Cm, which represent elementary exocytic events. An elevation of cAMP leaves the frequency of full-fusion events unchanged while increasing the frequency of transient events. These exhibited a wider fusion pore as measured by increased fusion pore conductance and a prolonged fusion pore dwell time. The probability of observing rhythmic reopening of transient fusion pores was elevated by dbcAMP. In conclusion, cAMP-mediated stabilization of wide fusion pores prevents vesicles from proceeding to the full-fusion stage of exocytosis, which hinders vesicle content discharge at high cAMP concentrations.
Bibliografsko gradivo je bilo uspešno dodano na polico.
Dodajanje bibliografskega gradiva na polico ni uspelo.
Gradivo je že na polici.
Trajna povezava
URL:
Faktor vpliva
Dostop do baze podatkov JCR je dovoljen samo uporabnikom iz Slovenije. Vaš trenutni IP-naslov ni na seznamu dovoljenih za dostop, zato je potrebna avtentikacija z ustreznim računom AAI.
Leto
Faktor vpliva
Izdaja
Kategorija
Razvrstitev
JCR
SNIP
JCR
SNIP
JCR
SNIP
JCR
SNIP
Faktor vpliva
Izberite knjižnično izkaznico:
Baze podatkov,
v katerih je revija indeksirana
Ime baze podatkov
Področje
Leto
Povezave do osebnih bibliografij avtorjev
Povezave do podatkov o raziskovalcih v sistemu SICRIS
Storitev za pridobivanje naslova trenutno ni dostopna, prosimo, poskusite še enkrat.
S klikom na gumb "V redu" boste potrdili zgoraj izbrano prevzemno mesto in dokončali postopek rezervacije.
S klikom na gumb "V redu" boste potrdili zgoraj izbrano prevzemno mesto in naslov za dostavo ter dokončali postopek rezervacije.
S klikom na gumb "V redu" boste potrdili zgoraj izbrani naslov za dostavo in dokončali postopek rezervacije.
Obvestilo
Trenutno je storitev za avtomatsko prijavo in rezervacijo nedostopna. Gradivo lahko rezervirate sami na portalu Biblos ali ponovno poskusite tukaj kasneje.
Citiranje
Funkcionalnost trenutno ni na voljo. Prosimo, poskusite kasneje.
PDF
