NaCl preference increases during pregnancy and lactation: assessment using brief access tests

Area of Science:

• Neuroscience
• Physiology
• Behavioral Science

Background:

• Pregnancy and lactation often correlate with increased salt intake.
• Previous studies relied on long-term consumption tests, unable to differentiate taste from postingestive factors.
• The precise mechanisms driving salt preference changes during these periods remain unclear.

Purpose of the Study:

• To investigate alterations in sodium chloride (NaCl) preference during pregnancy and lactation in rats.
• To determine if these preference changes are linked to dietary sodium content.
• To explore the role of taste versus postingestive factors in NaCl intake regulation.

Main Methods:

• Utilized a brief access taste test (lickometer) with nulliparous Long-Evans rats.
• Assessed NaCl preference across various concentrations (0.089 M to 0.5 M) during late pregnancy and lactation.
• Compared NaCl preference between rats on sodium-adequate (0.03% Na(+)) and sodium-rich (0.3% Na(+)) diets.

Main Results:

• Rats exhibited significantly higher lick rates for concentrated NaCl solutions (0.158 M, 0.281 M, 0.5 M) during late pregnancy and lactation.
• This increased preference for NaCl was observed irrespective of the dietary sodium content.
• The findings indicate that changes in NaCl preference are not directly tied to the amount of sodium consumed via diet.

Conclusions:

• The heightened preference for NaCl during pregnancy and lactation in rats is not solely driven by a physiological need for sodium.
• Taste factors appear to play a significant role in the observed increase in salt preference.
• This study suggests a dissociation between NaCl preference and sodium balance during reproduction.