ABCC1 and osteoporosis: ABCC1 expression is higher than ABCB1 in bone marrow and osteoblasts, potentially conferring protection against steroid-induced osteoporosis.23,39 In the current study, neither hydrocortisone nor corticosterone altered any of the other measurements of toxicity such as BP, arterial stiffness, lipolysis or the bone marker osteocalcin, but the treatment duration may have been insufficient to induce any change in these measurements.