Abstract
Vesicular monoamine transporters (VMATs) are involved in chemical transduction in monoaminergic neurons and various endocrine cells through the storage of monoamines in secretory vesicles. Mammalian pinealocytes contain more 5-hydroxytryptamine (5-HT) than any other cells and are expected to contain VMAT, although no information is available so far. Upon the addition of ATP, radiolabeled 5-HT was taken up by a particulate fraction prepared from cultured rat pinealocytes. The 5-HT uptake was inhibited significantly by bafilomycin A1 (an inhibitor of vacuolar H+-ATPase), 3,5-di-tert-butyl- 4-hydroxybenzylidenemalononitrile (a proton conductor), or reserpine (an inhibitor of VMAT). RT-PCR analysis suggested that VMAT type 1 (VMAT1), but not type 2, is expressed. Antibodies against VMAT1 recognized a single polypeptide with an apparent molecular mass of ~55 kDa, and specifically immunostained pinealocytes. VMAT1 immunoreactivity was high in the vesicular structures in the varicosities of long branching processes and was associated with 5-HT, but not with synaptophysin, a marker protein for microvesicles. The 5-HT immunoreactivity in the long branching processes disappeared upon incubation with reserpine. These results indicate that 5-HT, at least in part, is stored in vesicles other than microvesicles in pinealocytes through a mechanism similar to that of various secretory vesicles.
| Original language | English |
|---|---|
| Pages (from-to) | 2538-2545 |
| Number of pages | 8 |
| Journal | Journal of Neurochemistry |
| Volume | 73 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 1999 |
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Keywords
- 5- Hydroxytryptamine
- Exocytosis
- Melatonin
- Microvesicles
- Pinealocytes
- Vesicular monoamine transporter (VMAT)
ASJC Scopus subject areas
- Biochemistry
- Cellular and Molecular Neuroscience
Cite this
Vesicular monoamine transporter 1 is responsible for storage of 5- hydroxytryptamine in rat pinealocytes. / Hayashi, Mitsuko; Haga, Megumi; Yatsushiro, Shouki; Yamamoto, Akitsugu; Moriyama, Yoshinori.
In: Journal of Neurochemistry, Vol. 73, No. 6, 1999, p. 2538-2545.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Vesicular monoamine transporter 1 is responsible for storage of 5- hydroxytryptamine in rat pinealocytes
AU - Hayashi, Mitsuko
AU - Haga, Megumi
AU - Yatsushiro, Shouki
AU - Yamamoto, Akitsugu
AU - Moriyama, Yoshinori
PY - 1999
Y1 - 1999
N2 - Vesicular monoamine transporters (VMATs) are involved in chemical transduction in monoaminergic neurons and various endocrine cells through the storage of monoamines in secretory vesicles. Mammalian pinealocytes contain more 5-hydroxytryptamine (5-HT) than any other cells and are expected to contain VMAT, although no information is available so far. Upon the addition of ATP, radiolabeled 5-HT was taken up by a particulate fraction prepared from cultured rat pinealocytes. The 5-HT uptake was inhibited significantly by bafilomycin A1 (an inhibitor of vacuolar H+-ATPase), 3,5-di-tert-butyl- 4-hydroxybenzylidenemalononitrile (a proton conductor), or reserpine (an inhibitor of VMAT). RT-PCR analysis suggested that VMAT type 1 (VMAT1), but not type 2, is expressed. Antibodies against VMAT1 recognized a single polypeptide with an apparent molecular mass of ~55 kDa, and specifically immunostained pinealocytes. VMAT1 immunoreactivity was high in the vesicular structures in the varicosities of long branching processes and was associated with 5-HT, but not with synaptophysin, a marker protein for microvesicles. The 5-HT immunoreactivity in the long branching processes disappeared upon incubation with reserpine. These results indicate that 5-HT, at least in part, is stored in vesicles other than microvesicles in pinealocytes through a mechanism similar to that of various secretory vesicles.
AB - Vesicular monoamine transporters (VMATs) are involved in chemical transduction in monoaminergic neurons and various endocrine cells through the storage of monoamines in secretory vesicles. Mammalian pinealocytes contain more 5-hydroxytryptamine (5-HT) than any other cells and are expected to contain VMAT, although no information is available so far. Upon the addition of ATP, radiolabeled 5-HT was taken up by a particulate fraction prepared from cultured rat pinealocytes. The 5-HT uptake was inhibited significantly by bafilomycin A1 (an inhibitor of vacuolar H+-ATPase), 3,5-di-tert-butyl- 4-hydroxybenzylidenemalononitrile (a proton conductor), or reserpine (an inhibitor of VMAT). RT-PCR analysis suggested that VMAT type 1 (VMAT1), but not type 2, is expressed. Antibodies against VMAT1 recognized a single polypeptide with an apparent molecular mass of ~55 kDa, and specifically immunostained pinealocytes. VMAT1 immunoreactivity was high in the vesicular structures in the varicosities of long branching processes and was associated with 5-HT, but not with synaptophysin, a marker protein for microvesicles. The 5-HT immunoreactivity in the long branching processes disappeared upon incubation with reserpine. These results indicate that 5-HT, at least in part, is stored in vesicles other than microvesicles in pinealocytes through a mechanism similar to that of various secretory vesicles.
KW - 5- Hydroxytryptamine
KW - Exocytosis
KW - Melatonin
KW - Microvesicles
KW - Pinealocytes
KW - Vesicular monoamine transporter (VMAT)
UR - http://www.scopus.com/inward/record.url?scp=0032748150&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032748150&partnerID=8YFLogxK
U2 - 10.1046/j.1471-4159.1999.0732538.x
DO - 10.1046/j.1471-4159.1999.0732538.x
M3 - Article
C2 - 10582616
AN - SCOPUS:0032748150
VL - 73
SP - 2538
EP - 2545
JO - Journal of Neurochemistry
JF - Journal of Neurochemistry
SN - 0022-3042
IS - 6
ER -