scholarly journals Atropine-resistant Excitation of Motility of the Dog Stomach and Colon Induced by Stimulation of the Extrinsic Nerves and Their Centers

1978 ◽  
Vol 28 (2) ◽  
pp. 239-248 ◽  
Author(s):  
Takehiko SEMBA ◽  
Tsuyoshi MIZONISHI
Keyword(s):  
Stimulation Of ◽  
Extrinsic Nerves

Cholinergic control of canine antral immunoreactive gastrin release and motility

1982 ◽  
Vol 60 (7) ◽  
pp. 893-901 ◽  
Author(s):  
J. E. T. Fox ◽  
E. E. Daniel ◽  
J. Jury ◽  
N. S. Track ◽  
S. Chiu
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cell ◽  
Muscarinic Receptor ◽  
Muscle Cell ◽  
Gastrin Release ◽  
Field Stimulation ◽  
Antral Motility ◽  
Stimulation Of ◽  
Extrinsic Nerves

We used acute anaesthetized dogs to investigate the role of cholinergic receptors in the relationship between antral immunoreactive (I) gastrin release and antral motility. Electrical stimulation of extrinsic nerves via the cervical vagus or the nerve of Latarjet appeared to increase I gastrin release and antral motility by separate pathways as blockade of muscarinic receptors, i.e., atropinization inhibited motility but did not alter I gastrin release. On the other hand, blockade of nicotinic receptors by hexamethonium treatment obliterated I gastrin release induced by stimulation of the extrinsic nerves but only reduced motility. Field stimulation of intrinsic nerves via serosal electrodes also increased both I gastrin release and local motility. Since hexamethonium treatment only slightly reduced both I gastrin release and motility and atropinization eliminated both during field stimulation, the presence of a muscarinic receptor in the final pathway for each is proposed.Atropine eliminated carhachol-induced I gastrin release and motility increases, even in the presence of nerve blockade by tetrodotoxin. This suggests that this muscarinic receptor is on the smooth muscle cell itself and possibly on the gastrin cell. However a proposed role of the somatostatin cell in controlling gastrin release is also consistent with these data.Thus, both an intrinsic cholinergic and a separate extrinsic noncholinergic pathway are involved in antral release of I gastrin but initiation of motility appears to involve a final common pathway terminating in a muscarinic receptor on the smooth muscle cell.

Effects of 5-5'-Diphenyl-2-thiohydantoin (DPTH) and Thyroxine on the Ultrastructure and Chemical Composition of Rat Liver

1971 ◽  
Vol 29 ◽  
pp. 570-571
Author(s):  
E. A. Elfont ◽  
R. B. Tobin ◽  
D. G. Colton ◽  
M. A. Mehlman
Keyword(s):  
Chemical Composition ◽  
Rat Liver ◽  
Future Study ◽  
Mode Of Action ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Effective Inhibitor ◽  
Biochemical Effects ◽  
Glycerophosphate Dehydrogenase ◽  
Stimulation Of

Summary5,-5'-diphenyl-2-thiohydantoin (DPTH) is an effective inhibitor of thyroxine (T4) stimulation of α-glycerophosphate dehydrogenase in rat liver mitochondria. Because this finding indicated a possible tool for future study of the mode of action of thyroxine, the ultrastructural and biochemical effects of DPTH and/or thyroxine on rat liver mere investigated.Rats were fed either standard or DPTH (0.06%) diet for 30 days before T4 (250 ug/kg/day) was injected. Injection of T4 occurred daily for 10 days prior to sacrifice. After removal of the liver and kidneys, part of the tissue was frozen at -50°C for later biocheailcal analyses, while the rest was prefixed in buffered 3.5X glutaraldehyde (390 mOs) and post-fixed in buffered 1Z OsO4 (376 mOs). Tissues were embedded in Araldlte 502 and the sections examined in a Zeiss EM 9S.Hepatocytes from hyperthyroid rats (Fig. 2) demonstrated enlarged and more numerous mitochondria than those of controls (Fig. 1). Glycogen was almost totally absent from the cytoplasm of the T4-treated rats.

Gap junctions in the prothoracic glands of the tobacco hornworm, Manduca sexta

1992 ◽  
Vol 50 (1) ◽  
pp. 706-707
Author(s):  
Ji-da Dai ◽  
M. Joseph Costello ◽  
Lawrence I. Gilbert
Keyword(s):  
Gap Junctions ◽  
Small Molecules ◽  
Manduca Sexta ◽  
Freeze Fracture ◽  
Cell Communication ◽  
Cellular Level ◽  
Thin Sections ◽  
Prothoracic Glands ◽  
Polyhydroxylated Steroids ◽  
Stimulation Of

Insect molting and metamorphosis are elicited by a class of polyhydroxylated steroids, ecdysteroids, that originate in the prothoracic glands (PGs). Prothoracicotropic hormone stimulation of steroidogenesis by the PGs at the cellular level involves both calcium and cAMP. Cell-to-cell communication mediated by gap junctions may play a key role in regulating signal transduction by controlling the transmission of small molecules and ions between adjacent cells. This is the first report of gap junctions in the PGs, the evidence obtained by means of SEM, thin sections and freeze-fracture replicas.

Activator protein-1 is necessary for angiotensin-II stimulation of human adrenocorticotropin receptor gene transcription

2001 ◽  
Vol 268 (6) ◽  
pp. 1802-1810
Author(s):  
Danielle Naville ◽  
Estelle Bordet ◽  
Marie-Claude Berthelon ◽  
Philippe Durand ◽  
Martine Begeot
Keyword(s):  
Angiotensin Ii ◽  
Gene Transcription ◽  
Receptor Gene ◽  
Activator Protein 1 ◽  
Activator Protein ◽  
Stimulation Of
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