A COMPARISON BETWEEN THE EXOPHTHALMOS INHIBITING EFFECTS OF SODIUM-D- AND SODIUM-L-THYROXINE IN GUINEA PIGS

1962 ◽  
Vol 41 (4) ◽  
pp. 619-624 ◽  
Author(s):  
Björn Tengroth ◽  
Uno Zackrisson
Keyword(s):  
Hyaluronic Acid ◽  
Pituitary Gland ◽  
Guinea Pigs ◽  
Anterior Lobe ◽  
Optical Isomers ◽  
Connective Tissues ◽  
Response Curves ◽  
Experimental Animals ◽  
Inhibiting Effect ◽  
Caloric Effect

ABSTRACT The general change in the connective tissues which occurs in animals with experimentally produced exophthalmos, consists in an increase in the amount of hyaluronic acid, which binds the water in the connective tissue. Many regard this process as a stimulation of the mucinous system in the connective tissues, and consider this an explanation of the phenomenon of exophthalmos. When the experimental animals are injected with thyroxine or thyroid extract, the reaction observed is opposite to that seen following the injection of the anterior lobe of the pituitary gland. In the former case, there is a reduction in the amount of hyaluronic acid and consequently a decrease in the water content in the connective tissues. In the experiments in question, Na-d-thyroxine and Na-l-thyroxine), in crystalline form, were tested for their inhibiting effect on the development of exophthalmos in experimental animals. The animals used were male albino guinea-pigs. An extract of the anterior lobe of the pituitary gland (TSH Organon)) was used to produce exophthalmos. In previous work (Tengroth 1961), it was shown, using an X-ray measuring technique, that d-thyroxine, despite its poor caloric effect, like l-thyroxine had an exophthalmos-inhibiting effect. When comparing the dose-response curves of the exophthalmos-inhibiting properties of both these optical isomers, it appears that d-thyroxine has an inhibiting effect which is significantly greater than that of l-thyroxine. The significance of this observation is discussed.

Airway responses to inhaled ouabain and histamine in conscious guinea pigs

1986 ◽  
Vol 60 (6) ◽  
pp. 2089-2093 ◽  
Author(s):  
K. P. Agrawal ◽  
R. E. Hyatt
Keyword(s):  
Guinea Pigs ◽  
Airway Responsiveness ◽  
Maximal Response ◽  
Response Curves ◽  
Inhibiting Effect ◽  
Homeostatic Function ◽  
Positive Correlations ◽  
Airway Responses ◽  
Airway Conductance

Tracheal Na+-K+-ATPase activity is positively correlated with in vivo airway responsiveness to histamine. We wondered whether this were a chance association or whether it was directly related to the mechanism of hyperreactivity. Therefore, we obtained dose-response curves to aerosols of histamine and ouabain in guinea pigs to determine whether an in vivo relationship existed between the excitatory effects of histamine and the enzyme-inhibiting effect of ouabain. Airway responsiveness to ouabain was measured as the ouabain concentration producing a 30% decrease in specific airway conductance (ED30) or that producing a half-maximal response (ED50). Responsiveness to histamine was measured either as ED30 or as ED50. Significant positive correlations were noted between the log ED50 of ouabain and log histamine ED30 or ED50 (r = 0.81 and 0.83, respectively; P less than 0.001), and between log ouabain ED30 and log histamine ED30 and ED50 (r = 0.76 and 0.77, respectively; P less than 0.002). Pretreatment with ouabain increased airway responsiveness to histamine (P less than 0.05). We suggest that in hyperreactive airways Na+-K+-ATPase serves a homeostatic function of preventing Na+ and Ca2+ loading of the cell and that it is not directly responsible for the hyperreactivity.

scholarly journals Applications of Hyaluronic Acid in Ophthalmology and Contact Lenses

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2485
Author(s):  
Wan-Hsin Chang ◽  
Pei-Yi Liu ◽  
Min-Hsuan Lin ◽  
Chien-Ju Lu ◽  
Hsuan-Yi Chou ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Dry Eye ◽  
Water Retention ◽  
Contact Lenses ◽  
Anterior Segment ◽  
Vitreous Body ◽  
Material Surface ◽  
Connective Tissues ◽  
Water Retention Properties ◽  
Bull's Eye

Hyaluronic acid (HA) is a glycosaminoglycan that was first isolated and identified from the vitreous body of a bull’s eye. HA is ubiquitous in the soft connective tissues of animals and therefore has high tissue compatibility for use in medication. Because of HA’s biological safety and water retention properties, it has many ophthalmology-related applications, such as in intravitreal injection, dry eye treatment, and contact lenses. Due to its broad range of applications, the identification and quantification of HA is a critical topic. This review article discusses current methods for analyzing HA. Contact lenses have become a widely used medical device, with HA commonly used as an additive to their production material, surface coating, and multipurpose solution. HA molecules on contact lenses retain moisture and increase the wearer’s comfort. HA absorbed by contact lenses can also gradually release to the anterior segment of the eyes to treat dry eye. This review discusses applications of HA in ophthalmology.

Effect of hypothalamic neuropeptides on corticotrophin release from quarters of rat anterior pituitary gland in vitro

1984 ◽  
Vol 100 (2) ◽  
pp. 219-226 ◽  
Author(s):  
S. A. Nicholson ◽  
T. E. Adrian ◽  
B. Gillham ◽  
M. T. Jones ◽  
S. R. Bloom
Keyword(s):  
Pituitary Gland ◽  
Anterior Pituitary ◽  
Low Dose ◽  
Physiological Role ◽  
Anterior Pituitary Gland ◽  
High Concentration ◽  
Response Curves ◽  
Corticotrophin Releasing Factor ◽  
Basal Release

ABSTRACT The effect of six hypothalamic peptides on the basal release of ACTH and that induced by arginine vasopressin (AVP) or by ovine corticotrophin releasing factor (oCRF) from fragments of the rat anterior pituitary gland incubated in vitro was investigated. Dose–response curves to AVP and to oCRF were obtained, and the response to a low dose of oCRF was potentiated by a low dose of AVP. Basal release of ACTH was not affected by any of the peptides in concentrations in the range 10−12 to 10−6 mol/l, and only substance P (SP) and somatostatin (SRIF) inhibited significantly the response to oCRF in a dose-related manner. The responses to a range of doses of oCRF or AVP were reduced by 10−8 and 10 − 6 mol SP or SRIF/1, and to a greater extent by the higher dose. Except in the case of 10−6 mol SRIF/1 on the response to AVP, the response was not further diminished by preincubation of the tissue with the peptide before the stimulating agent was added. The inhibition of the responses to AVP or oCRF by 10−9 mol SP/1 was not potentiated by its combination with either 5 × 10−10 or 10−8 mol SRIF/1; the inhibitory effects were merely additive. The results suggest that although SRIF and SP are able to modulate the release of ACTH from the anterior pituitary gland, they do so only at a high concentration. In the case of SRIF these concentrations are several orders of magnitude higher than those reported to be present in the hypophysial portal blood and therefore a physiological role for this peptide in the control of ACTH secretion is unlikely. J. Endocr. (1984) 100, 219–226

On the content of prolan in the pituitary gland

1934 ◽  
Vol 30 (6) ◽  
pp. 634-634
Author(s):  
P. Badul
Keyword(s):  
Pituitary Gland ◽  
Histological Examination ◽  
Anterior Lobe ◽  
Posterior Lobe ◽  
Posterior Pituitary ◽  
Posterior Pituitary Lobe

The posterior lobe of the pituitary gland in a bull is free of prolan, while in a human it contains prolan. Only here it can be found in that part of the posterior pituitary lobe adjacent to the anterior lobe. In the bull, too, this part of the pituitary gland is completely free of prolan content. Histological examination shows that in humans, this part of the posterior lobe is crossed by bands of cells from the anterior lobe, which consist exclusively of basophilic cells.

scholarly journals Tethelin—the Alleged Growth-controlling Substance of the Anterior Lobe of the Pituitary Gland

1922 ◽  
Vol 16 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Jack Cecil Drummond ◽  
Robert Keith Cannan
Keyword(s):  
Pituitary Gland ◽  
Anterior Lobe

scholarly journals Analysis of Aflatoxin Biomarkers in the Hair of Experimental Animals

Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 570
Author(s):  
Innocent Mupunga ◽  
Ilse Janse van Rensburg ◽  
Nokuthula Luthuli ◽  
Ovokeroye A. Abafe ◽  
Leshweni J. Shai ◽  
...  
Keyword(s):  
Guinea Pigs ◽  
Hair Analysis ◽  
Historical Record ◽  
Body Fluids ◽  
Urine Samples ◽  
Long Term Effects ◽  
Experimental Animals ◽  
Explorative Study ◽  
Hair Samples

Analysis of body fluids and tissues of aflatoxin exposed individuals for the presence of aflatoxins and aflatoxin metabolites has emerged as a reliable indicator of exposure and metabolism of aflatoxins. However, current aflatoxin biomarkers are not appropriate for investigating the long-term effects of aflatoxin exposure. In this explorative study, we investigated the analysis of hair as a complementary or alternative matrix for the assessment of biomarkers of long-term aflatoxin exposure. Three groups of guinea pigs were orally dosed with 5 ugkg−1bw−1, 50 ugkg−1bw−1, and 100 ugkg−1bw−1 of AFB1. Urine and hair samples were collected on days 0, 1, 2, 3, 7, 30, 60, and 90 and analysed for AFB1 and AFM1 using UHPLC-MS/MS. AFB1 and AFM1 were detected in 75% and 13.6%, respectively, of the day 1 to day 7 urine samples. AFB1 was detected in hair samples collected from day 3 up to day 60. This is the first report to confirm the deposition of AFB1 in the hair of experimental animals. These findings indicate that hair analysis has the potential to provide an accurate long-term historical record of aflatoxin exposure with potentially important implications for the field of aflatoxin biomarkers.

scholarly journals Immunocytochemical demonstration of tissue-type plasminogen activator in endocrine cells of the rat pituitary gland.

1985 ◽  
Vol 101 (1) ◽  
pp. 305-311 ◽  
Author(s):  
P Kristensen ◽  
L S Nielsen ◽  
J Grøndahl-Hansen ◽  
P B Andresen ◽  
L I Larsson ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
Endocrine Cells ◽  
Large Population ◽  
Cell Types ◽  
Anterior Lobe ◽  
Tissue Type ◽  
Intermediate Lobe ◽  
Posterior Lobe ◽  
Rat Pituitary

We immunocytochemically stained rat pituitary glands using antibodies against plasminogen activators of the tissue type (t-PA) and the urokinase type (u-PA). A large population of endocrine cells in the anterior lobe of the gland displayed intense cytoplasmic immunoreactivity with anti-t-PA. In some areas of the intermediate lobe we found a weak staining, and we observed weakly staining granular structures in the posterior lobe. Controls included absorption of the antibodies with highly purified t-PA. In addition, SDS PAGE followed by immunoblotting of pituitary gland extracts revealed only one band with an electrophoretic mobility similar to that of t-PA when stained with anti-t-PA IgG. No u-PA immunoreactivity was detected in the rat pituitary gland. Sequential staining experiments using antibodies against growth hormone and t-PA demonstrated that the t-PA-immunoreactive cells constitute a large subpopulation of the growth hormone-containing cells. These findings represent the first direct evidence for the presence of t-PA in cell types other than endothelial cells in the intact normal organism. In this article we discuss the implications of the results for a possible role of t-PA in the posttranslational processing of prohormones.

THE RELATIONSHIP BETWEEN THE UTERUS AND OVARIES DURING EARLY PREGNANCY IN THE GUINEA-PIG

1972 ◽  
Vol 53 (2) ◽  
pp. 295-301 ◽  
Author(s):  
F. R. BLATCHLEY ◽  
B. T. DONOVAN
Keyword(s):  
Guinea Pig ◽  
Early Pregnancy ◽  
Guinea Pigs ◽  
Uterine Horn ◽  
Vaginal Smear ◽  
Corpora Lutea ◽  
Luteal Regression ◽  
Experimental Animals ◽  
Decidual Reaction ◽  
The Relationship

SUMMARY In mated guinea-pigs one uterine horn was rendered sterile by ligation of the oviduct 2 or 3 days after finding spermatozoa in the vaginal smear. Two glass beads were inserted into the sterile horn on each of days 3–12 and on day 14 in experimental animals but not in controls. At autopsy on day 20 large corpora lutea were present in both ovaries of the control animals. The presence of beads that had been introduced on days 3 and 4 and on days 10–14 resulted in marked regression of the corpora lutea in the adjacent ovary, in the absence of a decidual reaction in the uterus, while luteal enlargement typical of pregnancy occurred in the contralateral ovary. Beads inserted on days 5–8 caused decidualization in the sterile horn but did not induce premature luteal regression in the ipsilateral ovary.

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