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C Timo-Iaria

Publications and source records attributed to C Timo-Iaria.

51 records · Page 3Linked to original sources
PubMed1980

Gastric secretion provoked by functional cytoglucopoenia in the nuclei of the solitary tract in the cat.

1. A rhomboencephalic reflex loop involved in the gastrosecretory effect of functional cytoglucopoenia caused by 2-deoxy-D-glucose (2-DG) was investigated in thirty-five cats prepared with chronic gastric fistulae. 2. Injection of 60 mg 2-DG/kg in the vertebral artery of cats subjected to acute electrolytic transection of the pontomedullary transition produced gastric secretion. 3. Microinjection of 2-DG in the medial and in the lateral components of the nuclei of the solitary tract elicited an intense gastric secretion. Sites at the level of the obex were more effective than the caudalmost portions of the nuclei in causing the secretory effect. Microinjection of saline in the same nuclei was totally ineffective whereas both saline and 2-DG solutions induced secretion when microinjected in the dorsal nuclei of the vagus. The gastrosecretory effect of microinjection of saline and 2-DG in the dorsal nuclei of the vagus is ascribed to mechanical stimulation of the effector parasympathetic neurones that innervate gastric mucosa. 4. It is concluded that rhomboencephalic neurones sensitive to functional cytoglucopoenia are located in the nuclei of the solitary tract. Activation of these neurones conveys to effector neurones information that triggers gastric secretion.

Animals↗
PubMed1980

Pressor effect of the baroreceptor reflex, depressor effect of septal stimulation and their interactions.

Experiments on limbic modulation of the baroreceptor system show that changes in blood pressure caused by electrical stimulation of the septal area (PRS), carotid occlusion (PRC) and the interaction of these factors (PRI) can be described by power functions, if the pressure curves are divided into two branches, taking into account the minimum pressure attained during PRS and the time of occlusion release during PRC and PRI. A system analysis approach may be an important tool to disclose characteristics of changes undergone by blood pressure, which remain otherwise undetected.

Animals↗
PubMed1975

Neural systems responsible for the gastric secretion provoked by 2-deoxy-D-glucose cytoglucopoenia.

1. The central structures responsible for the gastrosecretory effect of cytoglucopoenia caused by 2-deoxy-D-glucose (2-DG) were investigated in 105 cats prepared with chronic gastric fistulae and subjected to various experimental procedures. 2. Bilateral electrolytic lesion of the caudalmost two thirds of globus pallidus almost suppressed the secretory response and caused aphagia and adipsia. 3. Secretion in response to 2-DG and feeding behaviour were entirely blocked after making a lesion in a large ventromedial area of the meso diencephalic transition comprising the ventral tegmental area of Tsai, the ventral tegmental decussation, the red nucleus, a ventral portion of the central grey matter, the interstitial nuclei of Darkschewitsch and of Cajal, the pre-rubral fields, the reticular part of substantia nigra, the internal portion of the cerebral peduncle and the ventral part of the mesencephalic reticular formation. 4. Microinjection of 2-DG in the medial forebrain bundle, at the level of the hypothalamus, caused intense gastric secretion, whereas the same procedure was totally ineffective when the caudalmost two thirds of the globus pallidus were stimulated. 5. Increasing doses of 2-DG, systemically injected, restored the secretory response in volume and acid concentration and output after intercollicular transection of the brain stem. After the transection, secretion of pepsin was only slightly increased when large doses of 2-DG were administered, thus suggesting a differential control of water, acid and pepsin secretion in response to cytoglucopoenia. 6. It is concluded that there are at least three reflex systems involved in gastric secretion due to cytoglucopoenia: (a) a reflex consisting of afferent and efferent pathways in the medial forebrain bundle area; (b) a reflex whose afferent side is from the hypothalamus and efferent side is from the globus pallidus; (c) a reflex with the afferent side probably originating in the liver and the efferent side in the lower brain stem. 7. The pathways involved in the first two arcs run along Nauta's limbic mid-brain circuit. The three systems are possibly related to control of secretion and feeding behaviour.

Afferent Pathways↗
PubMed1972

Site of action of 2-deoxy-D-glucose mediating gastric secretion in the cat.

1. Site of action of 2-deoxy-D-glucose (2-DG) responsible for its effect on gastric secretion was investigated in cats prepared with polyethylene or nylon cannulae chronically implanted in the antrum.2. The patterns of their basal secretion and secretory response to slow intravenous administration of 60 mg 2-DG/kg body wt. were determined. After being subjected to selective neural lesions the cats were tested again and the secretory response was compared with the control.3. The normal response to 2-DG in the cat is equivalent to that obtained in the dog. Volume, pH, acid concentration and output, chloride concentration and pepsin output attain peak values in 45-60 min.4. After intercollicular transection of the mid-brain no secretory response occurred except for a tendency of acid concentration to increase. Large lesions of several diencephalic structures did not suppress the secretory response. Only those cats with a circumscribed lesion of the lateral area of the medial and posterior hypothalamus were unresponsive to 2-DG. Acid secretion, as in the decerebrate animals, showed a slight tendency to increase after 2-DG. Lesions immediately rostral, medial and dorsal to the territory of the medial forebrain bundle were ineffective in preventing augmentation of secretion. Destruction of structures contributing fibres to the medial forebrain bundle at hypothalamic levels, such as the neocortex, amygdala, fornix, septal and preoptic areas, did not change the secretory response.5. Intrafascicular neurones of the medial forebrain bundle are suggested as the main site of action of 2-DG on gastric secretion.

Amygdala↗
PubMedDate not supplied

The direct potential of the intestinal wall. Its change in ischemia and revascularization. An experimental study in the rat.

The DC otential between the jejunal mucosa and the skin of the tail's root was measured in 29 rats. In twenty animals the superior mesenteric artery was clamped during up to VBJ minutes and recording of the DC potential was performed before vascular obstruction, during the period of ischaemia, and after revascularization was resumed when the clamp was removed. Prolonged ischaemia of the jejunum led to increasing reduction of the DC potential but recovery occurred about 75% of the rats when revascularization was established. The remaining 25% did not recover from vascular occlusion due to thrombosis or mechanical damage to the arterial wall. After removal of the elctrodes from the former group functional recovery of the intestinal function occurred in all the animals in which the removal was successful and no perforation of the intestinal wall was produced. Measuring transmural potential may be a convenient method to assess the viability of an infarcted intestine, thus aiding in selecting the appropriate therapeutic measures and in prognostic evaluation.

Animals↗