Studies of the rapid effects of parathyroid hormone and prostaglandins on 45Ca uptake into chick and rat bone in vivo.
Studies of the rapid effects of parathyroid hormone and prostaglandins on 45Ca uptake into chick and rat bone in vivo.
复制标题
研究甲状旁腺激素和前列腺素对鸡和大鼠体内 45Ca 吸收的快速影响。
作者：
C. Dacke;A. J. Shaw
甲状旁腺激素和各种肾上腺素对骨骼净摄取45 Ca的快速作用已在小鸡和未成年大鼠中进行了有限的平行研究。静脉注射牛（B）甲状旁腺激素（1-34）（bPTH（1-34））或16，16-二甲基前列腺素E2（16，16-二甲基PGE 2）在45 Ca标记的载体中，结合随后的组织同位素水平的微波固定，在鸡（12日龄）和大鼠（4周龄）中，45 Ca被迅速（3-15分钟）净抑制进入软骨内骨（股骨）。使用125 I标记的白蛋白和[14 C]甘露醇表明，这些反应并不能反映组织血管或细胞外空间的总体变化。在大鼠中，bPTH（1-84）也引起了显着的净抑制45钙摄取到股骨在10分钟。bPTH（1-34）和16，16-二甲基前列腺素E2产生一般较小的减少45钙摄取到鸡真皮骨（颅骨）在3-15分钟。在大鼠颅骨，然而，这些代理商刺激净摄取45钙在这些时间。当不进行微波固定时，大鼠颅骨的抑制反应减少或消失，而刺激反应增强。3分钟时，小鸡对天然前列腺素（PGE 1、PGE 2、PGF 2 α和PGI 2）的反应与对16，16-二甲基PGE 2的反应相似，但不太明显;股骨中的45 Ca摄入量受到抑制，颅骨中的45 Ca摄入量受到抑制，但程度较小。在大鼠中，PGE 1、PGE 2和PGF 2 α显示出减少股骨45 Ca摄取的趋势，而PGE 1和PGE 2均增加颅骨45 Ca摄取。
The rapid effects of parathyroid hormones and a variety of prostaglandins on net uptake of 45Ca into the skeleton have been investigated in chicks and, in a limited parallel study, in immature rats. Intravenous injection of bovine (b) parathyroid hormone(1-34) (bPTH(1-34)) or 16,16-dimethyl prostaglandin E2 (16,16-dimethyl PGE2) in a 45Ca-labelled vehicle, combined with subsequent microwave fixation of tissue isotope levels, resulted in rapid (3-15 min) net inhibition of 45Ca uptake into endochondral bone (femur) in chicks (12 days old) and rats (4 weeks old). Use of 125I-labelled albumin and [14C]mannitol indicated that these responses were not a reflection of gross changes in tissue vascular or extracellular space. In rats, bPTH(1-84) also caused significant net inhibition of 45Ca uptake into femur at 10 min. Both bPTH(1-34) and 16,16-dimethyl PGE2 produced generally smaller decreases in 45Ca uptake into chick dermal bone (calvarium) at 3-15 min. In rat calvarium, however, these agents stimulated net uptake of 45Ca at these times. When microwave fixation was omitted, inhibitory responses were reduced or disappeared, while the stimulatory response in rat calvarium was enhanced. Responses to natural prostaglandins (PGE1, PGE2, PGF2 alpha and PGI2) in chicks at 3 min were similar but less marked than those to 16,16-dimethyl PGE2; 45Ca uptake into femur and, to a lesser extent in calvarium, being inhibited. In rats, PGE1, PGE2 and PGF2 alpha showed a tendency to decrease 45Ca uptake into femur while PGE1 and PGE2 both increased 45Ca uptake into calvarium.