Abstract
Morphine (CAS 57-27-2) administration or its removal induces alterations in glucose
levels and oxidative status or behaviour signs, which may be hypothetically closely
related; if this is correct, controlling glucose changes may lead to modifications
in peroxide levels and in behaviour profile. It therefore seems important to find
a drug able to control alterations of glucose metabolism, peroxide generation and
behaviour symptoms in morphine or morphine withdrawal animals.
This paper describes the effects of morphine or morphine plus naloxone (CAS 51481-60-8)
on the plasma levels of glucose, malondialdehyde (MDA) (CAS 100683-54-3) and behavioural
signs in rats treated or not with α-lipoic acid (CAS 1077-28-7), known to interfere
with glucose and peroxide levels.
The administration of morphine or its removal by naloxone alters plasma glucose levels,
increases MDA values, and also affects signs such as pain threshold values, fecal
excretion and jumping behaviour.
The injection of α-lipoic acid decreases glycemia in rats treated with morphine or
morphine plus naloxone. This result may be due to the capacity of α-lipoic acid to
facilitate glucose transport and its utilization.
The administration of α-lipoic acid to rats given morphine or morphine plus naloxone
lowers total MDA levels because of its peroxide scavenging capacity.
In animals injected with morphine plus naloxone, which show altered pain thresholds,
high fecal excretion and jumping behaviour, treatment with α-lipoic acid increases
latency times, decreases fecal excretion and reduces jumping. These effects can be
attributed to the capacity of α-lipoic acid to interfere with mediators or peroxides
involved in the modified behaviour.
The glycemia levels, MDA values and behavioural signs seem to be interconnected in
the reported experiments. The administration of α-lipoic acid is demonstrated to control
the alterations in plasma glucose levels, peroxide values or behavioural profile in
animals receiving morphine or morphine plus naloxone.
Key words CAS 57-27-2 - CAS 1077-28-7 - CAS 51481-60-8 - α-Lipoic acid, effect on morphine withdrawal
signs, plasma glucose levels - plasma total malondialdehyde, reactive oxygen species
- Morphine - Naloxone