Biochemical markers of bone turnover were lower in lactating BLG-Cre/PTHrPlox/– mice. (a) Urine CTx levels were significantly lower (P < 0.05) in BLG-Cre/PTHrPlox/– mice (3.98 ± 0.82 μg/mmol creatinine, n = 8) than in controls (6.83 ± 0.29 μg/mmol creatinine, n = 7). (b) Osteocalcin concentrations in plasma were lower in BLG-Cre/PTHrPlox/– mice than controls (48.4 ± 5.1 ng/ml, n = 14, and 66.8 ± 12.5 ng/ml, n = 9, respectively), but these values were not significantly different.