Biomaterial Database

Footshock-induced analgesia: neurochemical correlates and pharmacological profile. 1985

G Urca, and S Segev, and Y Sarne

The administration of electric shock to the feet of rats can produce either opioid, naloxone-sensitive analgesia or non-opioid, naloxone-insensitive analgesia. In our hands opioid analgesia could be elicited in young Sabra rats (75 days of age) by all analgesia induction methods while older rats of the same strain and rats of the Charles River-derived strain (CR) showed only naloxone-resistant analgesia. We therefore compared the effects of 2 different footshock parameters, 3 min continuous shock (3 mA) and 30 min intermittent shock (30 min, 1 s on 5 s off) on the responsiveness to noxious stimuli and on brain enkephalins and humoral (H-) endorphin content in these strains of rats. As previously reported, only young Sabra rats showed opioid analgesia whereas all other animals displayed naloxone-resistant effects. In contrast, no differential effects on brain opioids could be seen in these species. Thus, 30 min of shock produced a significant increase in brain enkephalins and a noticeable albeit non-significant increase in brain H-endorphin. A slight non-significant increase was seen following brief footshock. To assess the nature of non-opioid analgesia further we examined the effects of both reserpine and a series of antagonists on the analgesia produced by 3 and 30 min of either brief or prolonged shock. Pretreatment with reserpine caused a significant attenuation of non-opioid analgesia with both shock parameters while none of the antagonists administered (methysergide, phentolamine, phenoxybenzamine, yohimbine, theophylline, diphenhydramine and scopolamine) were effective.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D009270	Naloxone	A specific opiate antagonist that has no agonist activity. It is a competitive antagonist at mu, delta, and kappa opioid receptors.	MRZ 2593-Br,MRZ-2593,Nalone,Naloxon Curamed,Naloxon-Ratiopharm,Naloxone Abello,Naloxone Hydrobromide,Naloxone Hydrochloride,Naloxone Hydrochloride Dihydride,Naloxone Hydrochloride, (5 beta,9 alpha,13 alpha,14 alpha)-Isomer,Naloxone, (5 beta,9 alpha,13 alpha,14 alpha)-Isomer,Narcan,Narcanti,Abello, Naloxone,Curamed, Naloxon,Dihydride, Naloxone Hydrochloride,Hydrobromide, Naloxone,Hydrochloride Dihydride, Naloxone,Hydrochloride, Naloxone,MRZ 2593,MRZ 2593 Br,MRZ 2593Br,MRZ2593,Naloxon Ratiopharm
D012110	Reserpine	An alkaloid found in the roots of Rauwolfia serpentina and R. vomitoria. Reserpine inhibits the uptake of norepinephrine into storage vesicles resulting in depletion of catecholamines and serotonin from central and peripheral axon terminals. It has been used as an antihypertensive and an antipsychotic as well as a research tool, but its adverse effects limit its clinical use.	Raunervil,Raupasil,Rausedil,Rausedyl,Serpasil,Serpivite,V-Serp,V Serp
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D004597	Electroshock	Induction of a stress reaction in experimental subjects by means of an electrical shock; applies to either convulsive or non-convulsive states.	Electroconvulsive Shock,Electroconvulsive Shocks,Electroshocks,Shock, Electroconvulsive,Shocks, Electroconvulsive
D004723	Endorphins	One of the three major groups of endogenous opioid peptides. They are large peptides derived from the PRO-OPIOMELANOCORTIN precursor. The known members of this group are alpha-, beta-, and gamma-endorphin. The term endorphin is also sometimes used to refer to all opioid peptides, but the narrower sense is used here; OPIOID PEPTIDES is used for the broader group.	Endorphin
D004745	Enkephalins	One of the three major families of endogenous opioid peptides. The enkephalins are pentapeptides that are widespread in the central and peripheral nervous systems and in the adrenal medulla.	Enkephalin
D000367	Age Factors	Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.	Age Reporting,Age Factor,Factor, Age,Factors, Age
D000698	Analgesia	Methods of PAIN relief that may be used with or in place of ANALGESICS.	Analgesias
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013045	Species Specificity	The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.	Species Specificities,Specificities, Species,Specificity, Species