In:
Neuroendocrinology, S. Karger AG, Vol. 80, No. 6 ( 2004), p. 343-354
Abstract:
Pituitary pars nervosa-pars intermedia of 〈 i 〉 Anolis carolinensis, Rana pipiens 〈 /i 〉 and 〈 i 〉 Hyla crysoscelis 〈 /i 〉 were perifused with synthetic medium 199 for up to 35 h. The pre- and post-perifused tissues were examined by electron microscopy. No neuronal endings were found in 〈 i 〉 Anolis 〈 /i 〉 tissue, but both 〈 i 〉 Rana 〈 /i 〉 and 〈 i 〉 Hyla 〈 /i 〉 had occasional synaptic end bulbs, which remained visible in the post-perifused tissue, although the synaptic vesicles appeared to cluster in the center of the end bulbs. Exposure to dopamine HCl from 10 〈 sup 〉 –8 〈 /sup 〉 to10 〈 sup 〉 –5 〈 /sup 〉 〈 i 〉 M 〈 /i 〉 had little effect on 〈 i 〉 Anolis 〈 /i 〉 pituitary but inhibited 〈 i 〉 Rana 〈 /i 〉 and 〈 i 〉 Hyla 〈 /i 〉 pituitaries from releasing skin-darkening substances. The skin-darkening substances, presumably derivatives of the proopiomelanocortin molecule, were assayed on 〈 i 〉 Anolis 〈 /i 〉 skin. No dose-dependent responses to dopamine were seen at the concentrations used. We saw the possibility of a short-loop feedback.
Type of Medium:
Online Resource
ISSN:
0028-3835
,
1423-0194
Language:
English
Publisher:
S. Karger AG
Publication Date:
2004
detail.hit.zdb_id:
1483028-0
Permalink