Rat lactotrophs isolated by fluorescence-activated cell sorting are electrically excitable

Area of Science:

• Endocrinology
• Neuroscience
• Cell Biology

Background:

• Lactotrophs, the prolactin-producing cells of the anterior pituitary, are crucial for various physiological processes.
• Understanding the electrophysiological properties of isolated lactotrophs is essential for studying pituitary cell function.

Purpose of the Study:

• To isolate viable lactotrophs from the adult female rat anterior pituitary using fluorescence-activated cell sorting (FACS).
• To assess the impact of FACS sorting on the membrane electrical properties of isolated lactotrophs.
• To characterize the electrophysiological behavior of cultured lactotrophs.

Main Methods:

• Cell surface labeling of lactotrophs with anti-prolactin antibodies.
• Isolation of labeled lactotrophs using fluorescence-activated cell sorting (FACS) with optimized low laser power (10 mW).
• Whole-cell patch clamp recordings from cultured lactotrophs (1-9 days post-isolation).

Main Results:

• Lactotrophs sorted with minimal laser power retained electrical excitability comparable to unsorted cells.
• Resting membrane potentials ranged from -22 mV to -60 mV.
• Over 80% of sorted lactotrophs generated action potentials in response to depolarizing stimuli.
• Spontaneous membrane potential fluctuations were observed in approximately 20% of cells.
• Both action potentials and spontaneous fluctuations involved sodium (Na+) and calcium (Ca2+) ion channels.

Conclusions:

• Fluorescence-activated cell sorting (FACS) can be used to isolate viable and electrophysiologically functional lactotrophs.
• Minimizing laser power during FACS is critical for preserving the membrane properties of sorted pituitary cells.
• Isolated lactotrophs exhibit characteristic electrical excitability involving Na+ and Ca2+ conductances, allowing for further investigation of their function.