The presence of vasoactive intestinal polypeptide (VIP)-like-immunoreactive nerve fibres and VIP-receptors in the pineal gland of the Mongolian gerbil (Meriones unguiculatus). An immunohistochemical and receptor-autoradiographic study.
By use of the indirect peroxidase-antiperoxidase immunohistochemical technique, nerve terminals exhibiting vasoactive intestinal polypeptide (VIP)-like-immunoreactivity were demonstrated in the pineal gland of the Mongolian gerbil (Meriones unguiculatus). Incubation of the superficial pineal gland of the gerbil with 60 pM of 125I-VIP showed that the gland exhibited saturation kinetics, and about 80% of the bound 125I-VIP could be displaced by adding a surplus of cold VIP. Incubation of unfixed, 0.1% and 4% paraformaldehyde-fixed cryostat sections of the gerbil forebrain with 125I-VIP also exhibited saturation kinetics, and displacement was possible by adding a surplus of the cold tracer. Receptor autoradiography on cryostat sections that had been incubated for 60 min with 125I-VIP showed a large number of grains over cortical areas, especially over the pyramidal layer of the hippocampus and the granular layer of the dentate gyrus. A prominent labelling of the pineal gland was also observed. The presence of VIP-like-immunoreactive nerve terminals and receptors for this molecule in the pineal gland of the Mongolian gerbil supports the biochemical studies demonstrating a stimulatory function of this molecule in the synthesis of melatonin.
Møller
M
M
Mikkelsen
J D
JD
Fahrenkrug
J
J
Korf
H W
HW
D000818:Animals; D001345:Autoradiography; D005260:Female; D005849:Gerbillinae; D007124:Immunoenzyme Techniques; D007457:Iodine Radioisotopes; D007700:Kinetics; D008297:Male; D010870:Pineal Gland / Q000166:cytology / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018005:Receptors, Vasoactive Intestinal Peptide; D014660:Vasoactive Intestinal Peptide / Q000032:analysis / Q000378:metabolism*
D007457:Iodine Radioisotopes; D011956:Receptors, Cell Surface; D018005:Receptors, Vasoactive Intestinal Peptide; D014660:Vasoactive Intestinal Peptide