OBJECTIVE: Dysregulated vascular resistance contributes to hypotension following preterm birth with sex-specific differences in microvascular function conferring a male disadvantage. We hypothesized that glucocorticoid mediated, sex-specific differences in the endogenous catecholamine norepinephrine and endothelially derived endothelin-1 (ET-1) contribute to microvascular dysfunction in preterm neonates in the immediate newborn period. METHODS: Umbilical and plasma ET-1 and normetanephrine, in 24 h urine samples, were determined at 24, 72, and 120 h of age in 24-34 week infants (n = 60). Microvascular blood flow was determined by laser Doppler flowmetry. RESULTS: In infants born within 72 h of antenatal glucocorticoid exposure, normetanephrine was higher in females than males (p = 0.048). Normetanephrine was inversely correlated with both microvascular blood flow at 24 h (p = 0.025) and CRIB II (p = 0.001). While umbilical arterial ET-1 was higher in females delivered <72 h after antenatal betamethasone (p = 0.006), plasma ET-1 did not correlate with microvascular blood flow or illness severity. Only sex and normetanephrine contributed significantly to both microvascular blood flow and endothelium dependant vasodilatation. CONCLUSIONS: These data support glucocorticoid mediated, sex-specific differences in mediators of vascular tone that may contribute to the impaired mechanisms compromising successful hemodynamic adaption to neonatal life and resulting in excess male morbidity and mortality.
OBJECTIVE: Dysregulated vascular resistance contributes to hypotension following preterm birth with sex-specific differences in microvascular function conferring a male disadvantage. We hypothesized that glucocorticoid mediated, sex-specific differences in the endogenous catecholaminenorepinephrine and endothelially derived endothelin-1 (ET-1) contribute to microvascular dysfunction in preterm neonates in the immediate newborn period. METHODS: Umbilical and plasma ET-1 and normetanephrine, in 24 h urine samples, were determined at 24, 72, and 120 h of age in 24-34 week infants (n = 60). Microvascular blood flow was determined by laser Doppler flowmetry. RESULTS: In infants born within 72 h of antenatal glucocorticoid exposure, normetanephrine was higher in females than males (p = 0.048). Normetanephrine was inversely correlated with both microvascular blood flow at 24 h (p = 0.025) and CRIB II (p = 0.001). While umbilical arterial ET-1 was higher in females delivered <72 h after antenatal betamethasone (p = 0.006), plasma ET-1 did not correlate with microvascular blood flow or illness severity. Only sex and normetanephrine contributed significantly to both microvascular blood flow and endothelium dependant vasodilatation. CONCLUSIONS: These data support glucocorticoid mediated, sex-specific differences in mediators of vascular tone that may contribute to the impaired mechanisms compromising successful hemodynamic adaption to neonatal life and resulting in excess male morbidity and mortality.
Authors: Celine Corbisier de Meautsart; Rebecca M Dyson; Joanna L Latter; Mary J Berry; Vicki L Clifton; Ian M R Wright Journal: Pediatr Res Date: 2016-08-06 Impact factor: 3.756
Authors: Rebecca M Dyson; Hannah K Palliser; Joanna L Latter; Megan A Kelly; Grazyna Chwatko; Rafal Glowacki; Ian M R Wright Journal: PLoS One Date: 2015-03-25 Impact factor: 3.240
Authors: Rebecca M Dyson; Hannah K Palliser; Joanna L Latter; Grazyna Chwatko; Rafal Glowacki; Ian M R Wright Journal: PLoS One Date: 2014-08-14 Impact factor: 3.240
Authors: Rebecca M Dyson; Hannah K Palliser; Anil Lakkundi; Koert de Waal; Joanna L Latter; Vicki L Clifton; Ian M R Wright Journal: Physiol Rep Date: 2014-09-17