Mice that are homozygous for the targeted mutation are viable, normal in size and do not display any gross physical or behavioral abnormalities. Expression of the receptor in the brain was significantly reduced as assessed by antagonist binding, which indicated a 90% reduction. The antagonist binding assay is not entirely specific for the receptor, as the residual 10% binding was attributable to a different subtype of receptor. Mutant mice exhibit a resting tachycardia of more than 180 beats/min greater than normal. Although mutant mice do not have elevated blood pressure, administration of the hypotensive agonist, dexmedetomidine, does not reduce blood pressure. Electrical stimulation of isolated heart atria at frequencies mimicking physiological sympathetic nerve activity results in increased release of noradrenaline at high frequencies and inhibited release at low frequencies. Noradrenaline release from isolated wildtype atria is higher at high frequencies than at low frequencies. Inhibition of neurogenic contraction response to electrical stimulation in isolated vas deferens by dexmedetomidine is reduced in the mutant.

These <i> Adra2a</i> knock-out mice exhibit a resting tachycardia significantly greater than normal and a reduced expression of the adrenergic receptor in the brain.

Typically mice are recovered in 12-16 weeks. Contact Customer Service to place an order or for more information.

<a target="_blank" href="https://www.jax.org/jax-mice-and-services/customer-support" rel="noreferrer">Contact Customer Service</a> for more information.