PMID- 7909701
OWN - NLM
STAT- MEDLINE
DCOM- 19940608
LR  - 20181130
IS  - 1221-356X (Print)
IS  - 1221-356X (Linking)
VI  - 31
IP  - 1-2
DP  - 1993
TI  - The mechanism involved in the central effect of 5-leu enkephalin on the 
      calcitonin secretion.
PG  - 49-55
AB  - Calcitonin (CT) secretion is not exclusively under the control of calcium levels 
      in the plasma, but also depends on the sympathetic-adrenergic tone. In previous 
      experiments we stressed out the possible role played by 5-leu enkephalin (5-LE) 
      in the nervous regulation of the CT secretion. Intracerebroventricular (i.c.v.) 
      5-LE in doses of 100 micrograms could act at a central level through a mechanism 
      independent from the noradrenergic pathways, since i.c.v. 6-OHDA and propranolol 
      could not interfere with its stimulatory effect on the CT content of the thyroid. 
      In the present experiments, performed in anaesthetized Wistar-Bratislava rats, we 
      studied the involvement of mu and delta receptors in the central effect of 5-LE 
      on the CT content of the thyroids and the CT levels in the plasma. These 
      parameters were measured in parallel, by means of a competitive radioimmunoassay 
      with double antibodies (Peninsula Lab.). 5-LE probably bound to both mu and delta 
      receptors, since its effect on the CT secretion was reversed by 13 micrograms of 
      naloxone (i.c.v.). A partial blockade, comparable to naloxone, was noticed after 
      382 micrograms of CTOP (i.c.v.), a specific antagonist of the mu 
      receptors--stressing out their involvement in the stimulatory effect of 5-LE on 
      the CT secretion. 250 Ug of ICI 174864 (i.c.v.), a selective antagonist the the 
      delta receptors completely blocked the stimulation induced by 5-LE on the CT 
      secretion to values significantly lower as compared to the controls and even to 
      the sympathectomized group. This suggests the tonic role played by enkephalins in 
      the CT secretion, through the central activation of delta receptors.(ABSTRACT 
      TRUNCATED AT 250 WORDS)
FAU - Gozariu, L
AU  - Gozariu L
AD  - Clinic of Endocrinology, Cluj-Napoca, Romania.
FAU - Gozariu, M S
AU  - Gozariu MS
FAU - Orbai, P
AU  - Orbai P
FAU - Sandor, V
AU  - Sandor V
FAU - Schmidt-Gayk, H
AU  - Schmidt-Gayk H
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PL  - Romania
TA  - Rom J Endocrinol
JT  - Romanian journal of endocrinology
JID - 9309485
RN  - 0 (Narcotic Antagonists)
RN  - 0 (Receptors, Opioid, delta)
RN  - 0 (Receptors, Opioid, mu)
RN  - 103429-31-8 
      (phenylalanyl-cyclo(cysteinyltyrosyl-tryptophyl-ornithyl-threonyl-penicillamine)threoninamide)
RN  - 36B82AMQ7N (Naloxone)
RN  - 51110-01-1 (Somatostatin)
RN  - 58822-25-6 (Enkephalin, Leucine)
RN  - 89352-67-0 (N,N-diallyl-tyrosyl-alpha-aminoisobutyric acid-phenylalanyl-leucine)
RN  - 8HW4YBZ748 (Oxidopamine)
RN  - 9007-12-9 (Calcitonin)
SB  - IM
MH  - Animals
MH  - Calcitonin/analysis/*drug effects/*metabolism
MH  - Drug Interactions
MH  - Enkephalin, Leucine/administration & dosage/analogs & derivatives/*pharmacology
MH  - Injections, Intraventricular
MH  - Naloxone/pharmacology
MH  - Narcotic Antagonists/pharmacology
MH  - Oxidopamine
MH  - Rats
MH  - Receptors, Opioid, delta/drug effects/physiology
MH  - Receptors, Opioid, mu/drug effects/physiology
MH  - Somatostatin/analogs & derivatives/pharmacology
MH  - Sympathectomy, Chemical
MH  - Thyroid Gland/chemistry/drug effects/metabolism
EDAT- 1993/01/01 00:00
MHDA- 1993/01/01 00:01
CRDT- 1993/01/01 00:00
PHST- 1993/01/01 00:00 [pubmed]
PHST- 1993/01/01 00:01 [medline]
PHST- 1993/01/01 00:00 [entrez]
PST - ppublish
SO  - Rom J Endocrinol. 1993;31(1-2):49-55.