Our objectives are to identify the neurotransmitter(s) released by birth canal mechanostimulation that mediate(s) the powerful analgesia triggered by this sensory stimulus, to augment this analgesia pharmacologically by inhibiting enzymatic breakdown of the neurotransmitter(s), and to determine whether these enqyme-inhibitors augment analgesia during natural parturition.
The specific aims are: 1) to determine whether the enkephalinase inhibitor, thiorphan, and the protease inhibitor, leupeptin, injected directly to the spinal cord (intrathecally) via chronic catheter, intensify and/or prolong the analgesia produced by artificial birth canal mechano-stimulation, and whether the opiate antagonist, naloxone, antagonizes this effect. This will provide evidence as to whether the activity of opiate and/or non-opiate analgesia-producing systems are potentiated by the enzyme inhibitors. 2) to determine whether the same pharmacological treatments intensify and/or prolong analgesia during the natural delivery of fetuses, which normally provide mechano-stimulation of the birth canal (e.g. cervix) as they are born. 3) to quantify, by radioimmunoassay, the levels of selected neuropeptides (e.g. vasoactive intestinal peptide and met-enkephalin) in superfusates of the spinal cord and homogenates of spinal cord segments, in response to analgesia-producing birth canal stimulation. This will provide evidence as to whether specific neuropeptides that produce analgesia are released in the spinal cord in response to sensory stimulation similar to that occurring normally during parturition. The ultimate goal is to utilize, pharmacologically and/or neurologically, this powerful analgesia-triggering natural sensory system for the control of pain in humans.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS022948-02
Application #
3405799
Study Section
Neurological Sciences Subcommittee 1 (NLS)
Project Start
1987-01-01
Project End
1989-12-31
Budget Start
1988-01-01
Budget End
1988-12-31
Support Year
2
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Rutgers University
Department
Type
Schools of Arts and Sciences
DUNS #
130029205
City
Newark
State
NJ
Country
United States
Zip Code
07102
Masters, D B; Jordan, F; Beyer, C et al. (1993) Release of amino acids into regional superfusates of the spinal cord by mechano-stimulation of the reproductive tract. Brain Res 621:279-90
Martinez-Gomez, M; Chirino, R; Beyer, C et al. (1992) Visceral and postural reflexes evoked by genital stimulation in urethane-anesthetized female rats. Brain Res 575:279-84
Cunningham, S T; Rosenblatt, J S; Komisaruk, B R (1992) Reflexive ovulation in the rat, induced by caesarean section, is blocked by pelvic and/or hypogastric nerve transection. Neuroendocrinology 56:393-6
Masters, D B; Komisaruk, B R (1991) Neonatal capsaicin treatment attenuates sensory-induced analgesia and nociception. Physiol Behav 50:901-6
Cunningham, S T; Steinman, J L; Whipple, B et al. (1991) Differential roles of hypogastric and pelvic nerves in the analgesic and motoric effects of vaginocervical stimulation in rats. Brain Res 559:337-43
McCarthy, M M; Masters, D B; Fiber, J M et al. (1991) GABAergic control of receptivity in the female rat. Neuroendocrinology 53:473-9
Steinman, J L; Faris, P L; Mann, P E et al. (1990) Antagonism of morphine analgesia by nonopioid cold-water swim analgesia: direct evidence for collateral inhibition. Neurosci Biobehav Rev 14:1-7
McCarthy, M M; Caba, M; Komisaruk, B R et al. (1990) Modulation by estrogen and progesterone of the effect of muscimol on nociception in the spinal cord. Pharmacol Biochem Behav 37:123-8
Beyer, C; Banas, C; Gonzalez-Flores, O et al. (1989) Blockage of substance P-induced scratching behavior in rats by the intrathecal administration of inhibitory amino acid agonists. Pharmacol Biochem Behav 34:491-5
Masters, D B; Jordan, F; Komisaruk, B R (1989) Regional in vivo superfusion of the spinal cord and KC1-induced amino acid release. Pharmacol Biochem Behav 34:107-12

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