TABLE 2

Effects of α_1A-adrenoceptor variations in vitro (overexpression in cell systems)

Variation	Parameter	Cell Line	Effect	Reference
c.460T>G (p.Ser154Ala)	Ligand binding affinity (pK_d)	Rat-1	Ser = Ala	Lei et al. (2005)
	NE-induced IP₃ production (max, EC₅₀)		Ser = Ala
	Desensitization of NE-induced IP₃ response		Ser = Ala
	Cell proliferation		Ser = Ala
c.497G>A (p.Arg166Lys)	Agonist binding affinity (pK_d)	Rat-1	Arg > Lys	Lei et al. (2005)
	Antagonist binding affinity (pK_d)		Arg = Lys
	NE-induced IP₃ production (max, response)		Arg = Lys
	NE-induced IP₃ production (EC₅₀)		Arg > Lys
	Desensitization of NE-induced IP₃ response		Arg = Lys
	Cell proliferation		Arg = Lys
c.599T>G (p.Ile200Ser)	Ligand binding affinity (pK_d)	Rat-1	Ile = Ser	Lei et al. (2005)
	NE-induced IP₃ production (max, EC₅₀)		Ile = Ser
	Desensitization of NE-induced IP₃ response		Ile = Ser
	Cell proliferation		Ile = Ser
c.739G>A (p.Gly247Arg)	Ligand binding affinity (pK_d)	Rat-1	Gly = Arg	Lei et al. (2005)
	NE-induced IP₃ production (max, EC₅₀)		Gly = Arg^{^a}
			Gly < Arg^{^b}
	Desensitization of NE-induced IP₃ response		Gly = Arg
	Cell proliferation		Gly < Arg
c.1039C>T (p.Arg347Cys)	Ligand binding affinity (pK_d)	Rat-1	Arg = Cys	Lei et al. (2005)
		CHO-K1^{^c}	Arg = Cys	Shibata et al. (1996)
	NE-induced IP₃ production (max, EC₅₀)	Rat-1	Arg = Cys	Lei et al. (2005)
	NE-induced increase in Ca²⁺	CHO-K1^{^c}	Arg = Cys	Shibata et al. (1996)
	Desensitization of NE-induced IP₃ response	Rat-1	Arg = Cys	Lei et al. (2005)
	Desensitization of NE-induced Ca²⁺ response	CHO-K1^{^c}	Arg = Cys	Shibata et al. (1996)
	Cell proliferation	Rat-1	Arg = Cys	Lei et al. (2005)
c.1395A>T (p.Glu465Asp)	Ligand binding affinity (pK_d)	Rat-1	Glu = Asp	Lei et al. (2005)
	NE-induced IP₃ production (max, EC₅₀)		Glu = Asp
	Desensitization of NE-induced IP₃ response		Glu = Asp
	Cell proliferation		Glu = Asp

max, maximum; NE, norepinephrine.
↵^a Cell line with high receptor expression: 1.5–2.4 pmol/mg.
↵^b Cell line with low receptor expression: 0.2–0.4 pmol/mg.
↵^c Receptor expression: 1 pmol/mg membrane protein.