Effect of parathyroid hormone and calcitonin on cholinergic markers in rat parathyroid gland.
The effect of parathyroid hormone (PTH) and calcitonin on 3H-choline uptake and on 3H-acetylcholine synthesis by rat parathyroid glands were examined. Incubation of tissue for 120 min with PTH or calcitonin resulted in an inverted bell-shaped, dose-dependent inhibition of 3H-choline uptake, with a maximal effect at 10(-9) M concentration. The effect of PTH on parathyroid choline uptake was blunted by preincubation with the PTH antagonist NLe(8-18)-PTH (3-34) amide. PTH brought about a dose-dependent inhibition of 3H-choline conversion to 3H-acetylcholine, with significant effects at 10(-8) M concentration or higher. This inhibitory effect of PTH on 3H-acetylcholine synthesis was blocked by co-incubation with the PTH antagonist NLe(8-18)-PTH (3-34) amide. Only at a 10(-7) M concentration calcitonin was effective to impair the in vitro conversion of radioactive choline into 3H-acetylcholine by parathyroid fragments. The results indicate that, in vitro, PTH, and to a less extent, calcitonin, inhibit cholinergic activity in rat parathyroid glands.
Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
J E
JE
Stern
D P
DP
Cardinali
D000109:Acetylcholine / Q000378:metabolism; D000704:Analysis of Variance; D000818:Animals; D002116:Calcitonin / Q000494:pharmacology*; D002794:Choline / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D066298:In Vitro Techniques; D010280:Parathyroid Glands / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000494:pharmacology*; D011869:Radioligand Assay; D051381:Rats; D017208:Rats, Wistar
D010281:Parathyroid Hormone; D002116:Calcitonin; D002794:Choline; D000109:Acetylcholine