The Effect of Neonatal Maternal Stress on Plasma Levels of Adrenocorticotropic Hormone, Corticosterone, Leptin, and Ghrelin in Adult Male Rats Exposed to Acute Heterotypic Stressor

Abstract

Activation of the hypothalamic-pituitary-adrenal (HPA) axis is important for maintenance of homeostasis during stress. Recent studies have shown a connection between the HPA axis and adipose tissue. The present study investigated the effect of acute heterotypic stress on plasma levels of adrenocorticotropic hormone (ACTH), corticosterone (CORT), leptin, and ghrelin in adult male rats with respect to neonatal maternal social and physical stressors. Thirty rat mothers and sixty of their male progeny were used. Pups were divided into three groups: unstressed control (C), stressed by maternal social stressor (S), stressed by maternal social and physical stressors (SW). Levels of hormones were measured in adult male progeny following an acute swimming stress (10 min) or no stress. ELISA immunoassay was used to measured hormones. The ACTH and CORT levels were significantly increased in all groups of adult progeny after acute stress; however, CORT levels were significantly lower in both neonatally stressed groups compared to controls. After acute stress, plasma leptin levels were decreased in the C and SW groups but increased in the S group. The data suggest that long-term neonatal stressors lead to lower sensitivity of ACTH receptors in the adrenal cortex, which could be a sign of stress adaptation in adulthood. Acute stress in adult male rats changes plasma levels of leptin differently relative to social or physical neonatal stressors.

Effects of Perinatal Stress and Drug Abuse on Maternal Behavior and Sensorimotor Development of Affected Progeny

“…Specifically, the postnatal S group gained significantly more weight than the others, regardless of prenatal treatment. One possible explanation could be that decreased plasma leptin levels in rats following maternal separation compared to controls , Smith et al 2006, Holubová et al 2016, which stimulates the appetite (Friedman 2011). This explanation is supported by maternal behavior in which stressed mothers breast-feed more in the passive position compared to controls, but spend the same amount of time as control in active position breast-feeding, meaning that, overall, the S-pups are breast-fed more often than controls (N-pups).…”

“…Maternal separation, as a social stressor, was conducted from PD 1-21, for 3 h per day, between 10:00-13:00 am , Lajud et al 2012, Holubová et al 2016. All pups (from appropriate groups S and SW) were gently removed from their maternity cage and placed in separate cage in other room for 3 h. The cage with pups was always placed on a heating pad to maintain normal body temperature.…”

Early Postnatal Stress Impairs Cognitive Functions of Male Rats Persisting Until Adulthood

“…MS, as a social stressor, was conducted daily (PD 1–21) for 3 h per day, between 8:00 am and 11:00 am (Plotsky et al, 2005 ; Lajud et al, 2012 ; Holubová et al, 2016 , 2018 ). Pups from group (S) were gently removed from their maternity cage and placed in a separate cage in another room; the mothers were left undisturbed in their home cages.…”

“…However, in our previous study, the group exposed to MS gained significantly more weight than non-stressed offspring, regardless of prenatal treatment (Holubová et al, 2017 ). One possible explanation could be decreased plasma leptin levels in rats following MS compared to controls (Salzmann et al, 2004 ; Walker et al, 2004 ; Schmidt et al, 2006 ; Friedman, 2011 ; Holubová et al, 2016 ), which stimulates the appetite (Friedman, 2011 ). This is further supported by behavior of pups affected MS that spend more time by feeding themselves from their mothers, i.e., stressed mothers breast-fed more in the passive position compared to controls.…”

“…We worked from the hypotheses that combination of prenatal MA and perinatal stress impairs learning ability and long-term memory retrieval, and that these effects can persist into adulthood. Testing used modified methods from our previous studies (Schutová et al, 2009 ; Holubová et al, 2016 , 2017 ; Macúchová et al, 2017 ).…”