ISSN:
1432-2013
Keywords:
Visceral nociceptor
;
Hyperalgesia
;
Prostaglandins
;
5-Hydroxytryptamine
;
Substance P
;
Acetylsalicylic acid
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract (1) An in vitro testis-superior spermatic nerve preparation was used to evaluate the effects of chemical agents applied in the bathing solution. Both directly evoked discharges and responses to algesic solutions [bradykinin (BK) 9×10−8 M, hypertonic saline 616 mM and high K+ solution 60 mM] of polymodal receptors were studied. (2) Prostaglandin (PG)-E2 (1.4×10−6–1.4×10−5 M) and serotonin (5-HT) (1.1×10−6 to 1.4×10−4 M) had only a weak excitatory effect. However, test responses to algesic substances were regularly greatly increased by PG-E2,-I2 and 5-HT. Concentrations of PG-E2 of 1.4×10−8 M or grealer augmented BK responses; higher concentrations and/or longer applications were needed to enhance responses to algesic salt solutions. Effective concentrations for the PGs and 5-HT were near those reported for inflamed tissues and exudate. (3) Aspirin (ASA) (5.5×10−4 M or greater, for more than 4 min) suppressed the responses to BK but not those evoked by hypertonic saline. The ASA effect on the BK response was largely restored by an addition of PG-E2. (4) Substance P also had a weak excitatory effect on some polymodal receptors, but no significant enhancement of the response to BK was noted. (5) These results further support a role of polymodal receptors in transmitting nociceptive information, of inflammatory origin.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00581157
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