ABC | Volume 112, Nº1, January 2019

Original Article Jevjdovic et al Prenatal stress affects rat heart ADRB1 Arq Bras Cardiol. 2019; 112(1):67-75 Table 3 – Maternal weight before treatment, maternal weight gain during last week of pregnancy (GD13-GD21), gestation length, maternal blood glucose level before and after stress exposure, litter size, and sex ratio Variable Control (n = 5) Stressed (n = 5) p Maternal weight before treatment (g) 347 ± 37.3 337 ± 40.2 0.6646 Maternal weight gain (g) 62.5 ± 4.43 50.5 ± 11.6 0.0872 Gestation length (days) 22.0 ± 0.71 22.2 ± 0.41 0.6355 Blood glucose levels (mM) before stress (GD13) 5.44 ± 0.21 5.55 ± 1.00 0.8162 Blood glucose levels (mM) after stress (GD21) 5.30 ± 0.42 5.63 ± 0.69 0.3737 Litter size 11.2 ± 2.77 11.8 ± 2.32 0.6891 Sex ratio 1.38 ± 0.4 1.18 ± 0.3 0.3805 GD13: gestational day 13; GD21: gestational day 21; Data are expressed as means ± standard deviation (SD). and 2C, approx. ADRB1:ADRB2 = 73%:23%, p < 0.01). Decreased apical ADRB1 mRNA levels were detected in PS females compared to control animals (Figure 2A, p = 0.048). Additionally, in PS females, we observed a trend of increase in apical ADRB2 mRNA levels compared with control. Since these changes resulted in the loss of differential ADRB subtype expression levels at the apical myocardium of PS females, two-way ANOVA analysis was performed. ANOVA test revealed significant interaction between prenatal treatment and receptor subtype expression levels (F(1,20) = 6.817, p = 0.0167). Altogether, these results indicate that prenatal stress differently affected ADRB1 and ADRB2 at the apical myocardium of female animals. Furthermore, we observed a trend of decrease in basal ADRB1 mRNA levels of PS females compared with control (Figure 2C p = 0.3434), such that basal myocardium of PS females did not display differential ADRB1 and ADRB2 mRNA expression pattern compared with control animals. One cannot exclude the effect of limited sample size to detect significant differences in ADRB gene expression between control and PS groups. Further research will be necessary to obtain a more detailed understanding of the underlying mechanisms resulting in altered gene expression pattern of basal cardiac adrenergic receptors of PS females. Male offspring from unstressed mothers, similar to female offspring, displayed higher ADRB1 than ADRB2 mRNA levels at the apex of left ventricle (Figure 2B, p = 0.0087). However, differently from female offspring, prenatal stress did not affect the predominant apical ADRB1 mRNA expression pattern of left ventricle in male offspring (Figure 2B). On the other hand, we detected similar ADRB1 and ADRB2 mRNA expression levels at the base of the left ventricle in control and PS male offspring (Figure 2D). Effects of prenatal stress on regional MAO-A gene expression in left ventricle of female and male offspring Prenatal stress did not significantly affect MAO-A mRNA expression at either apical or basal region of left ventricle in female and male offspring (Figure 3). Based on our results we observed a trend toward higher relative expression of MAO-A at the basal myocardium compared to the apical region of the left ventricle in male offspring (approximately 35-fold in control and 17.5-fold in PS animals, Figure 3B, D). Additionally, basal cardiac MAO-A demonstrated a trend toward higher expression in males than in females (Figure 3C, D, approximately, 4.7-fold between control groups and 5.1‑fold between PS groups). Table 4 – Offspring weight at birth, postnatal day 28 (PND28) and 60 (PND60) Variable C PS p Birth weight (g) Group 6.67 ± 0.904 6.39 ± 0.685 0.1562 Weight at PND28 (g) Group 94.5 ± 11.4 96.9 ± 13.2 0.6360 Male 96.8 ± 12.3 94.5 ± 10.3 0.7286 Female 92.2 ± 11.1 99.3 ± 16.2 0.3924 Weight at PND60 (g) Group 316 ± 50.9 317 ± 70.5 0.9790 Male 355 ± 29.7 377 ± 42.7 0.3354 Female 277 ± 33.6 257 ± 21.7 0.2454 C: offspring from unstressed mothers; PS: offspring from stressed mothers; PND28: postnatal day 28; PND60: postnatal day 60; Number of animals (n): n = 5-8 per group. Data are expressed as means ± standard deviation (SD). 70