RESUMO
Non-pharmacological early weaning (NPEW) leads offspring to obesity, higher liver oxidative stress and microsteatosis in adulthood. Pharmacological EW (PEW) by maternal treatment with bromocriptine (BRO) causes obesity in the adult progeny but precludes hepatic injury. To test the hypothesis that BRO prevents the deleterious changes of NPEW, we injected BRO into the pups from the NPEW model in late lactation. Lactating rats were divided into two groups: dams with an adhesive bandage around the body to prevent breastfeeding on the last 3 days of lactation and dams whose pups had free suckling (C). Offspring from both groups were subdivided into two groups: pups treated with BRO (intraperitoneal (i.p.) 4 mg/kg per day) on the last 3 days of lactation (NPEW/BRO and C/BRO) or pups treated with the vehicle (NPEW and C). At PN120, offspring were challenged with a high fat diet (HFD), and food intake was recorded after 30 minutes and 12 hours. Rats were killed at PN120 and PN200. At PN120, adipocyte size was greater in the NPEW group but was normal in the NPEW/BRO group. At PN200, the NPEW group presented hyperphagia, higher adiposity, adipocyte hypertrophy, hyperleptinaemia, glucose intolerance and increased hepatic triglycerides. These parameters were normalized in the NPEW/BRO group. In the feeding test, BRO groups showed lower HFD intake at 30 minutes than did their controls; however, at 12 hours, the NPEW group ate more HFD. The treatment with BRO can preclude some deleterious effects of the NPEW model, which prevented the development of overweight and its comorbidities.
Assuntos
Bromocriptina/farmacologia , Hiperfagia/prevenção & controle , Gordura Intra-Abdominal/efeitos dos fármacos , Lactação/metabolismo , Fígado/efeitos dos fármacos , Triglicerídeos/metabolismo , Desmame , Animais , Feminino , Glucose/metabolismo , Homeostase/efeitos dos fármacos , Hiperfagia/complicações , Gordura Intra-Abdominal/citologia , Lactação/sangue , Leptina/sangue , Fígado/metabolismo , Masculino , Obesidade/complicações , Ratos , Ratos WistarRESUMO
Previously, we demonstrated that maternal prolactin inhibition at the end of lactation, using bromocriptine (BRO), leads to an increase in leptin transfer via milk and induces the adult progeny to present hypothyroidism, leptin resistance and metabolic syndrome (obesity, hyperglycemia, hypertriglyceridemia, lower HDL). To test if these alterations are due to direct BRO action on the pups, in the present study we evaluated the long-term effects of direct injection of BRO (0.1µg/once daily) in male Wistar rats from postnatal (PN) day 1 to 10 (early treatment) or from PN11 to 20 (late treatment) on: food intake, body mass, cardiovascular parameters, hormone profile, hypothalamic leptin signaling, glucose homeostasis and thyroid hormone-dependent proteins. The respective controls were injected with methanol-saline. Offspring were killed at adulthood (PN180). Adult PN1-10 BRO-treated animals had lower food intake, hypoprolactinemia, lower leptin action (lower OBR-b, STAT-3 and SOCS-3 mRNA levels in the arcuate nucleus), lower TRH-TSH-thyroid axis as well as lower thyroid hormone markers. On the other hand, adult animals that were BRO-treated during the PN11-20 period showed hyperphagia, higher blood pressure, higher prolactinemia and OBR-b, higher TRH and plasma T3, hypercorticosteronemia as well as higher Dio2 and UCP1 mRNA expression in the brown adipose tissue. Glucose homeostasis was not changed treatment in either period. Our data show that early and late dopamine overexposure during lactation induces diverse metabolic disturbances later in life, increasing the risk of thyroid dysfunction and, consequently, changes in prolactinemia.