PMID- 3736332
OWN - NLM
STAT- MEDLINE
DCOM- 19860917
LR  - 20190701
IS  - 0024-3205 (Print)
IS  - 0024-3205 (Linking)
VI  - 39
IP  - 5
DP  - 1986 Aug 4
TI  - Glucagon is an antagonist of morphine bradycardia and antinociception.
PG  - 399-405
AB  - Glucagon and its receptors have been identified within the mammalian brain, and 
      their anatomical distribution correlates well with the distribution of opioid 
      peptides and their receptors. To evaluate possible physiological interactions 
      between these two peptidergic systems, we examined the effects of glucagon on two 
      opioid responses - bradycardia and antinociception. Glucagon administered either 
      intravenously (iv) (100-1000 micrograms/kg) or intracerebroventricularly (icv) (5 
      micrograms) significantly attenuated morphine-induced (200 micrograms/kg, iv) 
      bradycardia without producing any alterations in cardiovascular parameters when 
      given alone. Furthermore, glucagon did not antagonize the bradycardia produced by 
      phenyldiguanide (10 micrograms/kg, iv), a non-opioid substance. Peripheral (1 
      mg/kg, iv) and central (5 micrograms, icv) glucagon pretreatment antagonized 
      morphine-induced (7.5 mg/kg, intraperitoneal) antinociception by 67% and 86%, 
      respectively, at 30 minutes (as determined by the hot plate test). Glucagon 
      treatment alone at these doses did not alter baseline response latencies. In both 
      cases, central injections of glucagon were more effective than iv injections in 
      antagonizing morphine's effects. These findings demonstrate a central action for 
      glucagon and provide the first evidence that this neuropeptide may function as an 
      endogenous antagonist of opioid actions.
FAU - Malcolm, D
AU  - Malcolm D
FAU - Zaloga, G
AU  - Zaloga G
FAU - Chernow, B
AU  - Chernow B
FAU - Holaday, J
AU  - Holaday J
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Netherlands
TA  - Life Sci
JT  - Life sciences
JID - 0375521
RN  - 0 (Biguanides)
RN  - 76I7G6D29C (Morphine)
RN  - 9007-92-5 (Glucagon)
RN  - W8PKA3T2I3 (phenyl biguanide)
SB  - IM
MH  - *Analgesia
MH  - Animals
MH  - Biguanides/pharmacology
MH  - Glucagon/*pharmacology
MH  - Heart Rate/*drug effects
MH  - Kinetics
MH  - Male
MH  - Morphine/*antagonists & inhibitors
MH  - Rats
MH  - Rats, Inbred Strains
EDAT- 1986/08/04 00:00
MHDA- 1986/08/04 00:01
CRDT- 1986/08/04 00:00
PHST- 1986/08/04 00:00 [pubmed]
PHST- 1986/08/04 00:01 [medline]
PHST- 1986/08/04 00:00 [entrez]
AID - 0024-3205(86)90519-9 [pii]
AID - 10.1016/0024-3205(86)90519-9 [doi]
PST - ppublish
SO  - Life Sci. 1986 Aug 4;39(5):399-405. doi: 10.1016/0024-3205(86)90519-9.