[Extracellular pH, [K+] and synaptic transmission in the dorsal horn of spinal cord of rats in hypercapnia].
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.
Motin
V G
VG
Tarakanov
I A
IA
Semkina
G A
GA
Kaliuzhnyĭ
L V
LV
D000818:Animals; D004558:Electric Stimulation; D005110:Extracellular Space / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006935:Hypercapnia / Q000378:metabolism / Q000503:physiopathology*; D008839:Microelectrodes; D011188:Potassium / Q000378:metabolism* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000378:metabolism / Q000503:physiopathology*; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission
D011188:Potassium
Vnekletochnyĭ pH, [K+] i sinapticheskaia peredacha v dorsal'nom roge spinnogo mozga krys pri giperkapnii.