Role of adenosine in the hypoxic ventilatory response of the newborn piglet

1994 ◽  
Vol 17 (1) ◽  
pp. 50-55 ◽  
Author(s):  
Jose-Maria Lopes ◽  
G. Michael Davis ◽  
Krishna Mullahoo ◽  
Jacob V. Aranda
2015 ◽  
Vol 212-214 ◽  
pp. 39-45 ◽  
Author(s):  
Zhenzhong Bai ◽  
Nicolas Voituron ◽  
Tana Wuren ◽  
Florine Jeton ◽  
Guoen Jin ◽  
...  

1989 ◽  
Vol 67 (2) ◽  
pp. 797-803 ◽  
Author(s):  
B. Hannhart ◽  
C. K. Pickett ◽  
J. V. Weil ◽  
L. G. Moore

Pregnancy increases ventilation and ventilatory sensitivity to hypoxia and hypercapnia. To determine the role of the carotid body in the increased hypoxic ventilatory response, we measured ventilation and carotid body neural output (CBNO) during progressive isocapnic hypoxia in 15 anesthetized near-term pregnant cats and 15 nonpregnant females. The pregnant compared with nonpregnant cats had greater room-air ventilation [1.48 +/- 0.24 vs. 0.45 +/- 0.05 (SE) l/min BTPS, P less than 0.01], O2 consumption (29 +/- 2 vs. 19 +/- 1 ml/min STPD, P less than 0.01), and lower end-tidal PCO2 (30 +/- 1 vs. 35 +/- 1 Torr, P less than 0.01). Lower end-tidal CO2 tensions were also observed in seven awake pregnant compared with seven awake nonpregnant cats (28 +/- 1 vs. 31 +/- 1 Torr, P less than 0.05). The ventilatory response to hypoxia as measured by the shape of parameter A was twofold greater (38 +/- 5 vs. 17 +/- 3, P less than 0.01) in the anesthetized pregnant compared with nonpregnant cats, and the CBNO response to hypoxia was also increased twofold (58 +/- 11 vs. 29 +/- 5, P less than 0.05). The increased CBNO response to hypoxia in the pregnant compared with the nonpregnant cats persisted after cutting the carotid sinus nerve while recording from the distal end, indicating that the increased hypoxic sensitivity was not due to descending central neural influences. We concluded that greater carotid body sensitivity to hypoxia contributed to the increased hypoxic ventilatory responsiveness observed in pregnant cats.


2001 ◽  
Vol 164 (3) ◽  
pp. 437-442 ◽  
Author(s):  
HITOSHI NAKANO ◽  
SHIN-DA LEE ◽  
ANDREW D. RAY ◽  
JOHN A. KRASNEY ◽  
GASPAR A. FARKAS

1994 ◽  
Vol 77 (4) ◽  
pp. 1763-1768 ◽  
Author(s):  
T. Igarashi ◽  
M. Nishimura ◽  
Y. Akiyama ◽  
M. Yamamoto ◽  
K. Miyamoto ◽  
...  

To examine the role of endogenous adenosine on the hypoxic ventilatory response (HVR) enhanced during exercise, we measured HVR at rest and during mild exercise (12.5 W) in nine healthy men in a supine position after pretreatment with aminophylline (5 mg/kg), an adenosine receptor blocker, or dipyridamole (0.6 mg/kg), an adenosine uptake blocker, by using a 3-day double-blind placebo-controlled design. Although HVR was enhanced during exercise on all occasions, HVR with aminophylline [0.42 +/- 0.07 (SE) l.min-1.%fall-1 of arterial O2 saturation] was significantly lower than that with placebo (0.64 +/- 0.13 l.min-1.%fall-1) or dipyridamole (0.64 +/– 0.08 l.min-1.%fall-1) during exercise (P < 0.05 for both) at similar end-tidal PCO2 on the 3 days but not at rest. We then examined the changes in plasma K+ concentration ([K+]) and catecholamines, the other possible endogenous potentiators of the carotid body activity. The exercise- and hypoxia-induced increases in plasma [K+] were significantly lower with aminophylline (0.23 +/- 0.09 meq/l) than with the placebo (0.51 +/- 0.10 meq/l) or dypyridamole (0.58 +/- 0.13 meq/l) (P < 0.05 for both). We therefore conclude that aminophylline attenuates the enhancement of HVR during mild exercise and that this might be due to its attenuating effect on exercise- and hypoxia-associated increases in plasma [K+] rather than due to its antagonizing effect on endogenous adenosine.


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