Osteoblasts are involved in bone formation. Osteoclasts break down bone. Dysregulation of calcium homeostasis in osteoblasts and osteoclasts could lead to bone abnormalities. In the forward mode of the Na/calium exchanger calcium is effluxed from cells while in reverse mode there is an influx of calcium into cells via the Na/calcium exchanger.
Taurine inhibits the reverse mode of the Na/calcium exchanger. The Na/calcium exchanger (NCX) is expressed in osteoblasts. The taurine transporter is expressed in osteoblasts. In osteoblasts inhibting the reverse mode of the Na/calcium exchanger would increase calcium net efflux from osteoblasts which would increase bone formation. Taurine inhibits osteoclastogenesis through the taurine transporter. In osteoclasts inhibiting the reveres mode of the Na/calicum exchanger would inhibit the influx of calcium into osteoclasts from bone which would inhibit bone resorption.
Extracellular calcium levels are very tightly controlled and are very, very frequently tested. However intracellular homeostasis of calcium in osteoblasts and osteoclasts could be very imporant as to whethere there is bone bone growth or bone resorption. Taurine is involved in calcium homeostasis in cells. Taurine both increases bone growth and inhibits bone resorption. The positive effects of taurine on bone fomation could be via the inhibition of the reverse mode of the Na/calcium exchanger in osteoblasts and osteoclasts.