Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • 6-Hydroxydopamine  (1)
  • Alcohol  (1)
  • 1
    ISSN: 1432-2072
    Keywords: Key words Opioid antagonists ; Oral self-administration ; Intravenous self-administration ; Alcohol ; Operant behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  These experiments evaluated the ability of naltrexone (NTX) to reduce selectively oral and IV ethanol-reinforced responding, and examined the ethanol-NTX interaction in terms of the competitive opioid antagonist property of NTX. Five rhesus monkeys self-administered ethanol or sucrose and concurrently available water. Ethanol concentration was varied from 0.25% to 8% (w/v). Naltrexone (0.032–0.32 mg/kg) or saline was given IM 30 min prior to some drinking sessions. NTX (0.32 mg/kg) reduced ethanol-reinforced responding at the concentration that maintained the most responding (1% or 2%). NTX (0.1 mg/kg) reduced ethanol-reinforced responding, both at a low ethanol concentration (0.25%) that produced little ethanol intake (g/kg), and at a higher concentration (4%) with an appreciable intake. Thus, NTX (0.1 mg/kg) shifted the ethanol concentration-consumption curve down, in an insurmountable manner. NTX (0.1 and 0.32 mg/kg) also reduced reinforced responding for sucrose 100 g/l. In another experiment, three rhesus monkeys were given opportunities to self-administer ethanol IV. NTX (0.1 mg/kg) reduced the number of ethanol injections obtained by the monkeys at all ethanol doses tested (0.01, 0.032, and 0.1 g/kg per injection).The dose-effect curve was also shifted down. These results showed that NTX reduced behavior maintained by either ethanol or sucrose non-selectively. Furthermore, the ability of NTX to suppress ethanol-reinforced responding did not depend on the route of ethanol administration and was not overcome by increasing the concentration or dose per injection of ethanol.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-1912
    Keywords: Atrium ; β-Adrenoceptor ; 6-Hydroxydopamine ; Denervation ; Catecholamines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1. The characteristics of [3H]-dihydroalprenolol (DHA) binding were determined in atria from untreated chicks. [3H]-DHA binding to atrium homogenates was rapid (k1 = 8.52 × 108 1 mol−1 min−1), reversible (k −1 = 0.47 min−1), saturable, and of high affinity (K D = 0.61.−nmol/l). Isoprenaline competed for specific [3H]-DHA binding in a stereoselective manner; IC50 values (μmol/l) were: (−)isoprenaline 0.12, (+)isoprenaline 4.7. 2. The number of [3H]-DHA binding sites and catecholamine content of left and right atria were examined after injection of chicks with a single dose of 6-hydroxydopamine hydrobromide (100 mg/kg). There were transient increases in the number of [3H]-DHA binding sites in both the left and the right atrium after 6-OHDA treatment. These increases were quicker in onset and in offset in the right atrium than in the left atrium. [3H]-DHA binding was significantly increased- in the left atrium at 5 and 7 days, and in the right atrium at 3 and 5 days after 6-OHDA injection. 3. Saturation binding isotherms indicated that the increase in [3H]-DHA binding was due to an increase in β-adrenoceptor number with no change in affinity for [3H]-DHA. 4. Twenty four hours after 6-OHDA treatment there was a significant (80%) decrease in noradrenaline content of left and of right atria. 5. The decrease in noradrenaline content was reversible, noradrenaline levels returning to 55% of control in left atrium and to 71% of control in right atrium by 21 days after 6-OHDA treatment. These changes are consistent with reversible sympathetic denervation of the atria. 6. Adrenaline levels in the atria were 5 to 18% of total catecholamine (noradrenaline+adrenaline) content and were not significantly altered by 6-OHDA treatment.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...