Adaptation to phosphorus depletion: effect of streptozotocin-induced diabetes mellitus.
The effect of streptozotocin-induced diabetes mellitus (DM) on the adaptive response to phosphorus depletion (PD) was investigated in order to examine if DM has any influence on the adaptation to PD in rats. PD for 7 days caused a marked reduction in serum phosphate (Pi) levels and increase in serum calcium (Ca) concentrations in control rats. In contrast, the increase in serum Ca concentration caused by PD was almost entirely eliminated in DM rats. Similarly, while bone Ca and P content was decreased by 7 days of PD in control rats, no significant changes in bone mineral contents were observed in DM rats during PD. There was a marked reduction in fractional excretion of Pi and an increase in fractional excretion of Ca during PD in both control and DM rats. Serum somatomedin A levels measured by radioreceptor assay were lower in DM rats compared to those in control rats, but PD caused no significant changes in either group of animals. These results demonstrate that the development of hypercalcaemia and reduction in bone mineral content in response to PD were inhibited while the renal tubular responses to PD were not affected in DM rats. It is suggested that the inhibition of the hypercalcaemic response to PD in DM rats is mainly due to an inhibition of the resorptive response of bone to PD, and that insulin either directly or indirectly may play a permissive role in the development of the resorptive response of bone to PD.
D000222:Adaptation, Physiological; D000818:Animals; D001842:Bone and Bones / Q000378:metabolism; D002118:Calcium / Q000097:blood; D003404:Creatinine / Q000097:blood; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D008297:Male; D010710:Phosphates / Q000097:blood; D010758:Phosphorus / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013002:Somatomedins / Q000097:blood
D010710:Phosphates; D013002:Somatomedins; D010758:Phosphorus; D003404:Creatinine; D002118:Calcium