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Sexual dimorphism in stress-induced changes in adrenergic and muscarinic receptor densities in the lung of wild type and corticotropin-releasing hormone-knockout mice

2010; Informa; Volume: 13; Issue: 1 Linguagem: Inglês

10.3109/10253890902849840

1607-8888

Martina Nováková, Richard Květňanský, J Mysliveček,

Neuroendocrine regulation and behavior

We tested the hypothesis that single and repeated immobilization stress affect densities of α1-adrenoceptor (α1-AR) and β-AR subtypes, muscarinic receptors (MR), adenylyl cyclase activity (AC) and phospholipase C activity (PLC) in lungs of male and female wild type (WT) and corticotropin-releasing hormone gene (CRH-knockout (KO)) disrupted mice. We found sex differences in the basal levels of α1-AR subtypes (females had 2–3 times higher density of receptors than males) and MR (males had twice the density found in females). In marked contrast, β-AR subtype densities did not differ between sexes. CRH gene disruption decreased all three studied receptors in intact mice (to 20–50% of WT) in both sexes (except β1-AR in females). Stress induced sexually dimorphic responses, while all α1-AR subtypes decreased in females (to 30% of control approximately), only α1A-AR level diminished (about 50%) in males. β1-AR decreased in males (to about 40%) but remained stable in females. β2-AR diminished in females (to about 20–60%) and also in males (to about 30–60%). MR decreased in both sexes (approximately to 50%). AC activity diminished in males (to < 50%) while PLC activity was not changed. In CRH-KO mice, the stress response was severely diminished. Paradoxically, the receptor response to stress was less affected by CRH-KO in males than in females. AC activity did not change in CRH-KO mice. In conclusion, in mice the stress reaction is sexually dimorphic and an intact hypothalamo-pituitary–adrenocortical system is required for the normal reaction of pulmonary adrenergic and MR to stress.