Cc. Danielsen, Thermal stability of bone collagen as an indicator of bone turnover in gonadectomized and multiparous rats, CONNECT TIS, 39(4), 1998, pp. 295-307
Previous findings indicate that the thermal stability of bone collagen is r
elated to age, In this study, collagen from rat bone with reported differen
t turnover rates was investigated. Cortical and trabecular bone from femur
were obtained from intact, ovariectomized, orchidectomized and multiparous
breeder rats. Thermal stabilities of fibrillar collagen in decalcified bone
matrix and molecular collagen obtained by pepsin treatment were measured a
s shrinkage (T-s) and 'melting' temperature (T-m), respectively, Both T-s a
nd T-m of cortical collagen from intact female rats decreased in parallel w
ith age as previously found in male rats indicating that T-s and T-m measur
ements are interchangeable techniques in characterizing the thermal stabili
ty of bone collagen, T-m of trabecular collagen from intact rats decreased
with age, however, with a decay only one-third of that for cortical collage
n, The different rates possibly reflect different ages of collagen due to r
emodeling activity present in trabecular and minimal in cortical bone. Comp
ared with control rats the T-m of trabecular collagen from gonadectomized a
nd multiparous rats with a reported increased trabecular turnover rate was
elevated, whereas only minor variations in T-m of cortical collagen were fo
und. In conclusion, the thermal stability of bone collagen decreases with t
he age of the collagen. Increased bone turnover implies elevated thermal st
ability of bone collagen, Thus, thermal stability of bone collagen appears
to be an indicator of bone turnover.