Plasma leptin decreases during lactation in insectivorous bats

Area of Science:

• Reproductive biology
• Endocrinology
• Mammalian physiology

Background:

• High leptin levels were previously observed in pregnant little brown bats (Myotis lucifugus).
• Leptin is a hormone known to influence appetite and metabolism.

Purpose of the Study:

• To investigate leptin level changes during pregnancy and lactation in the big brown bat (Eptesicus fuscus).
• To compare leptin patterns between Eptesicus fuscus and Myotis lucifugus.
• To explore potential factors influencing post-partum leptin decline.

Main Methods:

• Blood samples were collected from pregnant and lactating Eptesicus fuscus.
• Leptin concentrations were measured using immunoassays.
• Leptin levels were correlated with body mass and time relative to parturition.

Main Results:

• Leptin increased after the first trimester of pregnancy in Eptesicus fuscus.
• Leptin decreased to baseline within one week post-parturition, with a 2-day half-life.
• Leptin correlated with body mass during lactation in E. fuscus, but not M. lucifugus.

Conclusions:

• Leptin increases during pregnancy and declines during lactation in free-ranging bats.
• Post-partum leptin decrease may involve placental factors and fat depletion.
• Leptin appears to play a role in mammalian reproduction, though its exact functions require further study.