Korean J Anesthesiol.  2005 Jun;48(6):651-655. 10.4097/kjae.2005.48.6.651.

Effect of Zaprinast, a Phosphodiesterse Inhibitor, on Formalin-induced Nociception and Hemodynamics in the Rat Spinal Cord

• Park SK
• Kim CM
• Jeong ST
• Kim SJ
• Shin DJ
• Bae HB
• Choi JI
• Jeong SW
• Chung SS
• Yoo KY
• Jeong CY
• Yoon MH

• KMID: 2238924
• DOI: http://doi.org/10.4097/kjae.2005.48.6.651

Abstract

BACKGROUND: Cyclic guanosine monophosphate (cGMP) is involved in antinociception and vascular relaxation. The effects of zaprinast, which increases the level of cGMP by inhibiting phosphodiesterase, in the spinal cord have not been reported. The aims of this study were to evaluate the effects of intrathecal zaprinast on stimulus evoked by formalin injection, and to observe hemodynamic change in the absence of formalin stimulation.
METHODS
Rats were implanted with lumbar intrathecal catheters. Intrathecal zaprinast was administered 10 min before formalin injection. After formalin injection, formalin-induced nociceptive behavior (flinching response) was observed for 60 min. Mean arterial pressure (MAP) and heart rate (HR) were measured after intrathecal delivery of zaprinast for a period of 60 min.
RESULTS
Intrathecal administration of zaprinast produced a dose-dependent suppression of flinches in both phases. Zaprinast had no evident effects on baseline MAP or HR.
CONCLUSIONS
Zaprinast, a phosphodiesterase inhibitor, is active against the nociceptive state evoked by formalin stimulus without affecting resting MAP or HR. Accordingly, spinal zaprinast may be useful in the management of tissue-injury induced pain.

Keyword

antinociception; cyclic guanosine monophosphate; formalin test; hemodynamics; spinal cord; zaprinast

MeSH Terms

Animals
Arterial Pressure
Catheters
Formaldehyde
Guanosine Monophosphate
Heart Rate
Hemodynamics*
Nociception*
Pain Measurement
Rats*
Relaxation
Spinal Cord*
Formaldehyde
Guanosine Monophosphate