Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 73 (1981), S. 219-222 
    ISSN: 1432-2072
    Keywords: Aging ; Catalepsy ; Haloperidol ; Maturation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Male Sprague-Dawley rats were evaluated between ages 18 and 825 days for responses to doses of haloperidol (0 and 0.05–10 mg/kg, IP). Catalepsy, ptosis, and inhibition of general motor activity showed steady decreases in sensitivity to the drug with age during the first 1.5 years of maturation, while rats older than 1.5 years had strikingly increased sensitivity to the activity-inhibiting and cataleptic effects of the drug. The efficacy of haloperidol on all tests in 110-day old rats was indistinguishable whether food was available continuously, or restricted to reduce body weight by 55%, indicating that the effects of maturation are due to aging and not to increasing body weight. The effects may be due to altered drug metabolism or altered sensitivity of the central nervous system to neuroleptic agents. Clinical impressions too, indicate that immature and elderly patients are more sensitive to these and other psychotropic drugs than are young adults.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 77 (1982), S. 150-155 
    ISSN: 1432-2072
    Keywords: Catalepsy ; Chronopharmacology ; Circadian rhythms ; Haloperidol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Circadian changes in behavioral responses to haloperidol were evaluated in rats under normal and altered lighting cycles. There was a 5.5-fold change in ED50 between the maximum (4 PM) and minimum (4 AM) cataleptic response to the drug under normal lighting (lights on 7 AM-7 PM). The rhythm was present whether the same rats were tested repeatedly, or fresh rats were used at each time to avoid drug effects which persist for at least several days. Under normal lighting, the maximum cataleptic effect of haloperidol corresponded closely to the light-phase minimum of spontaneous motor activity in untreated rats. Measures of sedation (ptosis and motor inhibition) induced by haloperidol yielded small circadian rhythms under normal lighting and were highly dependent on the baseline level of arousal. A month of constant light or dark, or reversed dark-light cycles had small effects on the sedative actions of haloperidol, although inhibition of locomotion tended to phase-shift with general arousal; these changes did not alter the catalepsy rhythm. While the circadian rhythm of spontaneous activity underwent a complete reversal within 1 month (t 1/2=17 days) of reversed lighting cycles, the catalepsy rhythm changed very gradually (t 1/2=82 days) and required nearly 6 months for complete reversal. Thus, catalepsy is a robust endogenously regulated circadian response that is only slowly influenced by altered lighting conditions which dissociate this rhythm of neuroleptic response from that of spontaneous general arousal. Endogenous neurobiologic and pharmacokinetic factors may contribute to circadian changes in neuroleptic responses.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...