Schleiffer R, Gairard A
Laboratoire de Physiologie, Pharmacologie Cellulaire et Moléculaire, Faculté de Pharmacie, ULP, Strasbourg, France.
Arch Int Pharmacodyn Ther. 1988 Mar-Apr;292:189-202.
The development of hypertension was delayed and attenuated after removal of the parathyroid glands in 6 weeks-old spontaneously hypertensive rats (SHR). The influence of parathyroidectomy on vascular contractile responses to noradrenaline was investigated on isolated aortic rings. An increased sensitivity to cumulative concentrations of noradrenaline in physiological solution containing 1.25 mmol/l calcium was observed 22 weeks after surgery in aorta from parathyroidectomized rats as compared to control rats. In response to a single concentration of noradrenaline (10(-5) mol/l), aortae from parathyroidectomized SHR rats compared to controls displayed an increased tonic component. No difference in contractile responses to calcium was observed between aortae from control and parathyroidectomized rats. These data are not specific for hypertension in SHR since after parathyroidectomy similar results were also obtained on normotensive Wistar rats. In addition, 8 weeks-old Wistar rats contractile responses evoked by cumulative concentrations of noradrenaline in solution containing 0.6 mmol/l calcium were decreased in aortae from both control and parathyroidectomized rats. Moreover, calculated contractile responses were similar in parathyroidectomized and control rats for the in vivo levels of ionized calcium. From these results it appears that removal of parathyroid glands in both spontaneously hypertensive and normotensive rats, leads to an increase in the in vitro vascular reactivity to noradrenaline, and the extracellular calcium concentration seems to play a key role in this mechanism.
在6周龄的自发性高血压大鼠（SHR）中，切除甲状旁腺后高血压的发展被延迟和减弱。在离体主动脉环上研究了甲状旁腺切除对血管对去甲肾上腺素收缩反应的影响。与对照大鼠相比，在手术后22周，在含1.25 mmol/L钙的生理溶液中，甲状旁腺切除大鼠主动脉对去甲肾上腺素累积浓度的敏感性增加。对于单一浓度的去甲肾上腺素（10⁻⁵ mol/L），与对照相比，甲状旁腺切除的SHR大鼠主动脉的紧张性成分增加。对照大鼠和甲状旁腺切除大鼠的主动脉对钙的收缩反应没有差异。这些数据并非SHR高血压所特有，因为甲状旁腺切除后在正常血压的Wistar大鼠中也得到了类似结果。此外，在含0.6 mmol/L钙的溶液中，对照和甲状旁腺切除的8周龄Wistar大鼠主动脉中，去甲肾上腺素累积浓度引起的收缩反应均降低。而且，甲状旁腺切除大鼠和对照大鼠体内游离钙水平的计算收缩反应相似。从这些结果看来，在自发性高血压和正常血压大鼠中切除甲状旁腺，都会导致体外血管对去甲肾上腺素的反应性增加，细胞外钙浓度似乎在这一机制中起关键作用。
