The carbachol-induced release of prothoracicotropic hormone from brain-corpus cardiacum-corpus allatum complex of the silkworm, Bombyx mori

The release of an insect neuropeptide hormone, bombyxin, is regulated by muscarinic transmission in the brain-corpus cardiacum-corpus allatum complex of the silkworm, Bombyx mori (Lepidoptera: Bomby cidae).

“…Bombyxin released into the medium was purified as described in Materials and Methods and subsequently detected by immunoblotting using anti-bombyxin antibody. B: Twenty Br-CC-CA complexes were incubated withthe system developed for the evaluation of PTTH release from the Br-CC-CA complex (Shirai et al, 1994(Shirai et al, , 1995. The concentration of carbachol and atropine used in this study was also based on the previous paper (Shirai et al, 1994).…”

“…B: Twenty Br-CC-CA complexes were incubated withthe system developed for the evaluation of PTTH release from the Br-CC-CA complex (Shirai et al, 1994(Shirai et al, , 1995. The concentration of carbachol and atropine used in this study was also based on the previous paper (Shirai et al, 1994). The tendency that a relatively high concentration is necessary for the induction and inhibition of neuropeptide hormone release from the Br-CC-CA complex may be due to the neural lamella and perineurium of the brain (Chapman, 1998).…”

“…We reported that the release of PTTH was triggered via the muscarinic acetylcholine receptor (mAChR) (Shirai et al, 1994), which was identified on the PTTH-producing neurosecretory cells (Aizono et al, 1997a). These results suggest that muscarinic transmission directly regulates the release of PTTH.…”

Involvement of Calcium, Inositol-1,4,5 Trisphosphate and Diacylglycerol in the Prothoracicotropic Hormone-Stimulated Ecdysteroid Synthesis and Secretion in the Prothoracic Glands of Bombyx mori

“…In experiments where the dose response to an experimental agent was investigated, glands from a pooled group were randomly selected for incubation at the indicated doses. In experiments requiring a Ca 2+ -free medium, Ringer's saline (Shirai et al, 1994) was prepared using NaCl (4.5 mM) in place of the standard 4.5 mM CaCl 2 . Hepes buffer (0.01 M, pH 6.8) and either EGTA (0.1 mM) or the indicated amount of Ca 2+ (in the form of CaCl 2 ) were added prior to use (Hayes et al, 1995).…”

Small GTP-binding proteins in the brain-corpus cardiacum-corpus allatum complex of the silkworm,Bombyx mori: Involvement in the secretion of prothoracicotropic hormone

“…In contrast to many biochemical findings, mechanism controlling PTTH release remains unclear. We, therefore, have investigated the control mechanism of PTTH release with neurotransmitters from BR-CC-CA in Bombyx mori, and found that carbachol (acetylcholine agonist) induced the PTTH release via the muscarinic acetylcholine receptor (Shirai et al, 1994(Shirai et al, , 1995Aizono et al, 1997).…”