Prolactin inhibition in dams during lactation programs for overweight and leptin resistance in adult offspring.

Maternal malnutrition during lactation reduces prolactin (PRL) and milk production, alters milk composition, and programs the body weight of the offspring. Our study aimed to evaluate the long-term effects of maternal hypoprolactinemia at the end of lactation on food ingestion, body weight, amount of retroperitoneal white adipose tissue (RPWAT), leptinemia, and anorectic leptin effect in the adult offspring. Lactating rats were treated with bromocriptine (BRO), a PRL inhibitor, 1 mg twice a day, or saline (C - control) for the last 3 days of lactation. The body weight and food intake were monitored, and after sacrifice at 180 days, the RPWAT was weighted. In a second experiment, the anorectic leptin effect was tested on 180-day-old animals. Adult offspring whose mothers were BRO-treated showed higher body weight (10%), higher amount of RPWAT (2 x 3 times), higher total body fat (+39%), and hyperleptinemia (2 x 9 times) when compared with C, although food intake did not alter. After injection of leptin, the food ingestion at 2, 4 and 6 h was unaffected in BRO animals, confirming a resistance to the anorectic effect of leptin. Since the maternal PRL inhibition during lactation programs, a higher body weight with no alteration of food ingestion, we suggest a hypometabolic state. The leptin anorectic resistance can be due to the hyperleptinemia. We suggest that PRL changes during lactation can regulate body weight during adulthood.