scholarly journals Pancreatic Response to Bolus Injection of Cholecystokinin-pancreozymin in Anaesthetized and Conscious Rats Fed Raw Soyaflour

1982 ◽  
Vol 35 (5) ◽  
pp. 505 ◽  
Author(s):  
PS Oates ◽  
RGH Morgan
Keyword(s):  
Bolus Injection ◽  
Acinar Cells ◽  
Simple Relationship ◽  
Experimental Conditions ◽  
Conscious Rats ◽  
Anaesthetized Rats ◽  
Hypertrophied Cell ◽  
Protein Output ◽  
Conscious Animals ◽  
Basal Flow

Pancreatic secretion was studied in rats fed raw soyaflour before (basal) and after stimulation with cholecystokinin-pancreozymin (CCK) given in either ascending or descending dose orders ranging from 1� 25 to 20 or from 20 to 1� 25 Crick-Harper-Raper units (CHRU). These results were compared with those reported previously for animals fed a stock cube diet. Two experimental conditions were used: anaesthetized animals were tested immediately after cannulation of the pancreatic duct and conscious animals were tested 48 h after surgery. Basal flow was significantly increased in anaesthetized and conscious rats fed RSF compared with the respective animals fed cubes. Mean basal protein output was also increased, but this difference was not significant. The pancreatic response to the ascending and descending doses of CCK in anaesthetized rats fed RSF was linearly related to the log of the dose of CCK in both animals fed RSF and cubes, though the response to CCK was greater in the rats fed RSF. When ascending doses of CCK were given to conscious rats fed RSF, the protein output increased up to 10 CHRU of CCK but was inhibited by 20 CHRU of CCK, whereas it decreased after the first dose of CCK (1�25 CHRU) in animals fed cubes. When descending doses of CCK were given to animals fed RSF, protein output was greatest after the first dose and no simple relationship between dose and response was seen. Compared with rats fed cubes, the pancreas in rats fed RSF thus appears to respond to a given dose of CCK with increased secretion, and conscious animals fed RSF can tolerate a higher dose of CCK before protein output is inhibited. This is consistent with an increased population of acinar cells in the animals fed RSF, with each hypertrophied cell responding to CCK with increased secretion.

scholarly journals Pancreatic Response of Anaesthetized and Conscious Rats to Bolus Injection of Cholecystokinin-Pancreozymin

1981 ◽  
Vol 34 (3) ◽  
pp. 283 ◽  
Author(s):  
PS Oates ◽  
RGH Morgan
Keyword(s):  
Pancreatic Duct ◽  
Intravenous Injection ◽  
Pancreatic Secretion ◽  
Bolus Injection ◽  
Conscious Rats ◽  
Anaesthetized Rats ◽  
Protein Output

Pancreatic secretion was studied in anaesthetized rats tested immediately after surgery or in conscious rats tested 48 h after the cannulation of the pancreatic duct. Pancreatic flow, protein output and enzyme output were measured over a 30-min period in the unstimulated state and after the intravenous injection of bolus doses of cholecystokinin-pancreozymin (CCK-PZ) ranging from 1�25 to 20 Crick-Harper-Raper units (CHRU). Each animal received three doses of CCK-PZ, as either ascending or descending doses.

Nephron filtration rate in conscious rats recovering from anesthesia

1977 ◽  
Vol 232 (4) ◽  
pp. F329-F334
Author(s):  
J. P. Bonvalet ◽  
M. Champion ◽  
F. Wanstok ◽  
G. Berjal
Keyword(s):  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Filtration Rate ◽  
Experimental Conditions ◽  
Nephron Filtration Rate ◽  
Conscious Rats ◽  
Anesthetized Rats ◽  
Saline Loading ◽  
Single Nephron ◽  
Infusion Technique

Single-nephron glomerular filtration rate (SNGFR) of superficial (S) and juxtamedullary (JM) nephrons was measured in conscious rats with a [14C]ferrocyanide infusion technique. Experiments were carried out in nondiuretic (ND), salt-loaded (SL), and hemorrhagic hypotensive (HH) rats. Mean SNGFR values of S and JM nephrons were 48.7 +/- 4.5 SE and 61.7 +/- 4.2 in ND, 73.6 +/- 8.7 and 87.5 +/- 10.8 in SL, and 29.9 +/- 5.9 and 36.4 +/- 7.1 in HH rats. These values are higher than the values reported in anesthetized rats. The S-to-JM SNGFR ratio was not significantly different in the three experimental conditions (ND, 0.788 +/- 0.032; SL, 0.843 +/- 0.018; and HH, 0.824 +/- 0.030), and did not differ from the values reported in anesthetized rats in similar experimental conditions. It is concluded that anesthesia exerts a depressive effect on GFR, but does not modify intrarenal SNGFR distribution. Neither saline loading nor hemorrhagic hypotension induces SNGFR intrarenal redistribution in conscious rats.

scholarly journals A simple method for oral administration of drugs in solid form to fully conscious rats

1983 ◽  
Vol 17 (1) ◽  
pp. 50-54 ◽  
Author(s):  
E. R. Lax ◽  
K. Militzer ◽  
A. Trauschel
Keyword(s):  
Oral Administration ◽  
Tissue Damage ◽  
Training Period ◽  
Solid Materials ◽  
Simple Method ◽  
Conscious Rats ◽  
Solid Form ◽  
Conscious Animals ◽  
Peristaltic Action ◽  
Design And Application

The design and application of a simple capsule administration tube for miniature capsules are described. Experiments with rats have shown that the tube is capable of depositing capsules at the distal end of the oesophagus. Regardless of the location of the capsule in the oesophagus, provided normal peristaltic action occurs, the capsule will have reached the stomach and discharged its contents within 10 min. After a short training period of 3-4 days the insertion of the tube does not appear to cause the rats undue discomfort, nor does it cause tissue damage. The procedure, which can be performed rapidly by 1 technician, is ideally suited for dispensing solid materials to fully conscious animals.

Morphological Changes of Intercellular Junctions in the Rat Submandibular Gland Treated by Long-term Repeated Administration of Isoproterenol

1987 ◽  
Vol 66 (8) ◽  
pp. 1303-1309 ◽  
Author(s):  
T. Inoue ◽  
H. Yamane ◽  
T. Yamamura ◽  
M. Shimono
Keyword(s):  
Gap Junctions ◽  
Tight Junctions ◽  
Morphological Changes ◽  
Freeze Fracture ◽  
Acinar Cells ◽  
Intercellular Junctions ◽  
Repeated Administration ◽  
Experimental Conditions ◽  
Significant Difference

Long-term repeated administration of isoproterenol (lPR) 2 mg/100 g bw, once daily for ten days, resulted in morphological changes in the intercellular junctions of rat submandibular glands, which were investigated by means of the freeze fracture technique. A significantly increased number of tight-junctional strands was present. These junctional strands extended much deeper toward the basal membrane than those in normal acinar cells. The basal frontier strands that branched from the networks of tight junctions were elongated and had either free-endings or terminal loops, which were more frequently observed in the IPR-treated acinar cells than in untreated acinar cells. Some of the strands of tight junctions were connected to small gap junctions. The diameters of gap junctions were not significantly different from those of control acinar cells. However, smooth areas devoid of particles were found intermingling with the usual packed particles in irregularly shaped small gap junctions. There was no significant difference between the desmosomes of IPR-treated and untreated acinar cells, in terms of either morphology or distribution. These changes in junctional morphology in the IPR-treated acinar cells resemble those seen in salivary glands during development, and in some experimental conditions including tumorous changes.

Liposome-induced pulmonary hypertension: properties and mechanism of a complement-mediated pseudoallergic reaction

2000 ◽  
Vol 279 (3) ◽  
pp. H1319-H1328 ◽  
Author(s):  
Janos Szebeni ◽  
Lajos Baranyi ◽  
Sandor Savay ◽  
Mihaly Bodo ◽  
David S. Morse ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Complement Activation ◽  
Bolus Injection ◽  
Natural Antibody ◽  
Binding Potential ◽  
Experimental Conditions ◽  
Multilamellar Liposomes ◽  
Slow Infusion ◽  
Administration Method ◽  
Liposomal Drugs

Intravenous injection of liposomes can cause significant pulmonary hypertension in pigs, a vasoconstrictive response that provides a sensitive model for the cardiopulmonary distress in humans caused by some liposomal drugs. The reaction was recently shown to be a manifestation of “complement activation-related pseudoallergy” (CARPA; Szebeni J, Fontana JL, Wassef NM, Mongan PD, Morse DS, Dobbins DE, Stahl GL, Bünger R, and Alving CR. Circulation 99: 2302–2309, 1999). In the present study we demonstrate that the composition, size, and administration method of liposomes have significant influence on pulmonary vasoactivity, which varied between instantaneously lethal (following bolus injection of 5 mg lipid) to nondetectable (despite infusion of a 2,000-fold higher dose). Experimental conditions augmenting the pulmonary hypertensive response included the presence of dimyristoyl phosphatidylglycerol, 71 mol% cholesterol, distearoyl phosphatidylcholine, and hemoglobin in liposomes, increased vesicle size and polydispersity, and bolus injection vs. slow infusion. The vasoactivity of large multilamellar liposomes was reproduced with human C3a, C5a, and xenoreactive immunoglobulins, and it correlated with the complement activating and natural antibody binding potential of vesicles. Unilamellar, monodisperse liposomes with 0.19 ± 0.10 μm mean diameter had no significant vasoactivity. These data indicate that liposome-induced pulmonary hypertension in pigs is multifactorial, it is due to natural antibody-triggered classic pathway complement activation and it can be prevented by appropriate tailoring of the structure and administration method of vesicles.

scholarly journals Intercostal muscle motor behavior during tracheal occlusion conditioning in conscious rats

2016 ◽  
Vol 120 (7) ◽  
pp. 792-800 ◽  
Author(s):  
Poonam B. Jaiswal ◽  
Paul W. Davenport
Keyword(s):  
Respiratory Activity ◽  
Motor Behavior ◽  
Respiratory Muscles ◽  
Experimental Period ◽  
Emg Activity ◽  
Intercostal Muscle ◽  
Load Compensation ◽  
Conscious Rats ◽  
Loaded Breathing ◽  
Conscious Animals

A respiratory load compensation response is characterized by increases in activation of primary respiratory muscles and/or recruitment of accessory respiratory muscles. The contribution of the external intercostal (EI) muscles, which are a primary respiratory muscle group, during normal and loaded breathing remains poorly understood in conscious animals. Consciousness has a significant role on modulation of respiratory activity, as it is required for the integration of behavioral respiratory responses and voluntary control of breathing. Studies of respiratory load compensation have been predominantly focused in anesthetized animals, which make their comparison to conscious load compensation responses challenging. Using our established model of intrinsic transient tracheal occlusions (ITTO), our aim was to evaluate the motor behavior of EI muscles during normal and loaded breathing in conscious rats. We hypothesized that 1) conscious rats exposed to ITTO will recruit the EI muscles with an increased electromyogram (EMG) activation and 2) repeated ITTO for 10 days would potentiate the baseline EMG activity of this muscle in conscious rats. Our results demonstrate that conscious rats exposed to ITTO respond by recruiting the EI muscle with a significantly increased EMG activation. This response to occlusion remained consistent over the 10-day experimental period with little or no effect of repeated ITTO exposure on the baseline ∫EI EMG amplitude activity. The pattern of activation of the EI muscle in response to an ITTO is discussed in detail. The results from the present study demonstrate the importance of EI muscles during unloaded breathing and respiratory load compensation in conscious rats.

Involvement of central vs. peripheral mechanisms in mediating sympathoadrenal activation in endotoxic rats

1993 ◽  
Vol 265 (3) ◽  
pp. R683-R688 ◽  
Author(s):  
Z. Z. Zhou ◽  
S. B. Jones
Keyword(s):  
Significant Fraction ◽  
Regulatory Mechanisms ◽  
Maximal Response ◽  
Plasma Norepinephrine ◽  
Plasma Catecholamine ◽  
Marked Elevation ◽  
Conscious Rats ◽  
Pithed Rats ◽  
Conscious Animals ◽  
Intact Rats

The contribution of central vs. peripheral mechanisms in mediating increases in plasma norepinephrine (NE) and epinephrine (Epi) during endotoxicosis were studied. Plasma catecholamine responses after endotoxin were assessed in conscious animals and in animals without central regulatory mechanisms (pithed rats). In conscious rats, endotoxin (1.5 mg/kg i.v.) induced a marked elevation in plasma NE after 90 min (3-fold), but elevations were not seen in pithed rats. Endotoxin also induced a profound increase (12- to 13-fold) in plasma Epi in conscious rats, but increases were less (2- to 3-fold) and delayed in pithed rats. These results suggest that central mechanisms are essential in plasma NE response to endotoxic challenge, whereas plasma Epi response involves both central and peripheral mechanisms, with the former being dominant. In conscious adrenal-denervated animals, plasma Epi was not elevated until 90 min postendotoxin. This delayed Epi elevation was approximately one-third of the maximal response observed in conscious adrenal-intact rats. In pithed adrenal-denervated rats, plasma Epi at 90 min postendotoxin was also increased to a level comparable to that in pithed adrenal-intact rats. These results imply that a significant fraction of peripheral release of Epi with endotoxicosis is nonneurogenic.

Sign in / Sign up

Export Citation Format

Share Document