Motin V G, Tarakanov I A, Semkina G A, Kaliuzhnyĭ L V
Biull Eksp Biol Med. 1992 Jan;113(1):8-10.
In rats anaesthetized with +-chloralose the changes in extracellular pH and K+ in spinal cord dorsal horn were studied using pH and K+ ion-selective electrodes. The addition of 20% CO2 into inhaled air decreased the basal level of [pH]0 from 7.35 +/- 0.01 to 6.78 +/- 0.09 pH units and increased the basal level of [K+]0 from 3.1 +/- 0.1 to 5.14 +/- 0.8 mM. Electrocutaneous supramaximal (10 mA) simulation of both hind paws with the frequency 30 and 100 Hz induced the shift in the concentration of H+ and K+ by 0.15-0.2 unit and 2-2.5 mM, respectively. Under hypercapnia this shift of pH decreased by 36.9 +/- 8.5% at 30 Hz frequency of electrocutaneous stimulation and by 41.9 +/- 6.1% at 100 Hz frequency. The K+ shift decreased by 11.5 +/- 1.3% and by 17.3 +/- 1.5% under similar conditions. Hypercapnia induced by addition of 20% CO2 into inhaled air decreased also the focal potential amplitude by 16.8 +/- 4%. Thus, hypercapnia induces the increase of [K+]0 and [pH]0 and the decrease of recorded indicators in response to electrocutaneous stimulation. Total depression of synaptic transmission and analgetic effect occur due to these changes of ions distribution.
在用+-氯醛糖麻醉的大鼠中，使用pH和K+离子选择性电极研究了脊髓背角细胞外pH值和K+的变化。向吸入空气中添加20%的二氧化碳可使[pH]0的基础水平从7.35±0.01降至6.78±0.09 pH单位，并使[K+]0的基础水平从3.1±0.1升至5.14±0.8 mM。以30和100 Hz的频率对双后爪进行电皮肤超强（10 mA）刺激，分别导致H+和K+浓度变化0.15 - 0.2单位和2 - 2.5 mM。在高碳酸血症下，在30 Hz的电皮肤刺激频率下，pH值的这种变化降低了36.9±8.5%，在100 Hz频率下降低了41.9±6.1%。在类似条件下，K+的变化分别降低了11.5±1.3%和17.3±1.5%。向吸入空气中添加20%的二氧化碳引起的高碳酸血症还使局部电位幅度降低了16.8±4%。因此，高碳酸血症会导致[K+]0和[pH]0升高，并使电皮肤刺激后的记录指标降低。由于离子分布的这些变化，会出现突触传递的完全抑制和镇痛作用。
