preferred_name: serotonin(in) + n H(+)(out) = serotonin(out) + n H(+)(in)
preferred_name_lc: serotonin(in) + n h(+)(out) = serotonin(out) + n h(+)(in)
label: serotonin(in) + n H(+)(out) = serotonin(out) + n H(+)(in)
label_lc: serotonin(in) + n h(+)(out) = serotonin(out) + n h(+)(in)