Effect of parathyroid hormone on the increase in serum glucose and insulin levels after a glucose load to thyroparathyroidectomized rats.
Thyroparathyroidectomy (TPTX) caused a significant increase in serum glucose and a corresponding fall in serum calcium in both fed and fasted rats. The increase in serum glucose, induced by TPTX, was markedly potentiated by a single intraperitoneal administration of calcium (2 mg/100 g BW) which caused a significant elevation of serum calcium in thyroparathyroidectomized rats. Parathyroid hormone (PTH; 20 U/100 g BW) administered subcutaneously to thyroparathyroidectomized rats, caused a significant decrease in serum glucose (0.1 g/100 g BW) to sham-operated rats significantly increased both serum glucose and insulin. The rise of serum glucose produced by a glucose load was markedly potentiated by TPTX, but the increase in serum insulin was not promoted significantly. The administration of PTH decreased both serum glucose and insulin levels increased by a glucose load to thyroparathyroidectomized rats, in a dose-dependent manner. The administration of calcitonin (80 MRC mU/100 g BW) significantly prevented the effect of PTH to decrease serum glucose after a glucose load to thyroparathyroidectomized rats, and calcitonin increased serum insulin. These results suggest that the effect of PTH on serum glucose does not involve insulin secretion.
D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D005947:Glucose / Q000494:pharmacology*; D007328:Insulin / Q000097:blood*; D008297:Male; D010280:Parathyroid Glands / Q000502:physiology; D010281:Parathyroid Hormone / Q000494:pharmacology*; D051381:Rats; D013965:Thyroidectomy
D001786:Blood Glucose; D007328:Insulin; D010281:Parathyroid Hormone; D005947:Glucose