THE UPTAKE OF (6,7-3H) 17β-OESTRADIOL BY TISSUES OF THE DOMESTIC FOWL DURING AN OVULATION CYCLE

1969 ◽  
Vol 60 (2) ◽  
pp. 210-215 ◽  
Author(s):  
R. A. Hawkins ◽  
P. J. Heald ◽  
Patricia Taylor

ABSTRACT The uptake of radioactivity by various tissues of the domestic fowl has been studied following a single intravenous dose, at different times during the ovulatory cycle. It has been found that the pituitary gland showed significant cyclical accumulations of radioactivity, when calculated in terms of dpm/mg wet weight, at different stages in the ovulatory cycle, the greatest accumulation being in the period 12–16 hours before the expected ovulation. The results are discussed in relation to the role of oestrogens in the timing of ovulation. It is proposed that oestradiol acts as a major regulator of the timing of ovulation in the domestic fowl.

1963 ◽  
Vol 44 (3) ◽  
pp. 467-474 ◽  
Author(s):  
S. Kanematsu ◽  
J. Hilliard ◽  
C. H. Sawyer

ABSTRACT A single intravenous dose of reserpine (0.5 mg/kg) lowers the level of pituitary prolactin and induces lactation in ovariectomized, oestrogen-primed rabbits. These effects can also be produced by placing a discrete electrolytic lesion in the basal tuberal hypothalamus, and following such a lesion, reserpine exerts no further effects on pituitary prolactin or mammary gland activation. In contrast, when reserpine is administered to rabbits bearing lesions elsewhere in the hypothalamus, depletion of pituitary prolactin and lactation ensues. These results suggest that reserpine-induced prolactin depletion of the pituitary gland, with subsequent lactation, is mediated by a system within the basal tuberal hypothalamus.


Author(s):  
Robert H. Liss ◽  
Frances A. Cotton

Daunomycin, an antibiotic used in the clinical management of acute leukemia, produces a delayed, lethal cardiac toxicity. The lethality is dose and schedule dependent; histopathologic changes induced by the drug have been described in heart, lung, and kidney from hamsters in both single and multiple dose studies. Mice given a single intravenous dose of daunomycin (10 mg/kg) die 6-7 days later. Drug distribution studies indicate that the rodents excrete most of a single dose of the drug as daunomycin and metabolite within 48 hours after dosage (M. A. Asbell, personal communication).Myocardium from the ventricles of 6 moribund BDF1 mice which had received a single intravenous dose of daunomycin (10 mg/kg), and from controls dosed with physiologic saline, was fixed in glutaraldehyde and prepared for electron microscopy.


1969 ◽  
Vol 60 (2) ◽  
pp. 199-209 ◽  
Author(s):  
R. A. Hawkins ◽  
P. J. Heald ◽  
Patricia Taylor

ABSTRACT A limited investigation of the distribution of radioactivity in the tissues of the adult laying hen has been made at differing times after intravenous injection of (6,7-3H) 17β-oestradiol. Uptake by all tissues examined was maximal between 2.0 and 4.0 minutes after injection. There was a marked retention of radioactivity by the oviduct and the liver. Of cerebral tissues examined the uptake of radioactivity was greatest in the pituitary gland. This uptake varied according to the physiological state of the bird. Calculations based on the rates of clearance of intravenous (6,7-3H) 17β-oestradiol indicate that in the adult bird the rate of secretion by the ovary is of the order of 1–2.0 mg oestradiol/24 h.


Author(s):  
Dr.Suraj Kumbar ◽  
Dr.Lohith BA ◽  
Dr.Ashvinikumar M ◽  
Dr. Amritha R ◽  
Dr. Shameem Banu

We are in technical era where there is more of sedentary life style and stress along with this urbanization is affecting our quality of food and health. This is leading to many lifestyle disorders and hormonal imbalances in our body. Hypothyroidism one among the endocrinal disorder. Thyroid is an endocrinal gland secrets T3 and T4 hormones regulated by TSH which is secreted by Pituitary gland. These hormones have two major effects on the body, 1) To increase the overall metabolic rate in the body 2) To stimulate growth in children. Hypothyroidism is common health issue in India. The highest prevalence of hypothyroidism (13.1%) is noted in people aged 46-54yrs old. With people aged 18-35 yrs being less affected (7.5%). To prevent these hazards Panchakarma is beneficiary to maintain metabolic rate. Here an attempt is made to diagnose hypothyroidism in the light of Ayurveda and management guidelines through Panchakarma.


1996 ◽  
Vol 40 (5) ◽  
pp. 1237-1241 ◽  
Author(s):  
T Whittem ◽  
K Parton ◽  
K Turner

The effects of poly-L-aspartic acid on the pharmacokinetics of gentamicin were examined by using a randomized crossover trial design with the dog. When analyzed according to a three-compartment open model, poly-L-aspartic acid reduced some first-order rate equation constants (A3, lambda 1, and lambda 3), the deep peripheral compartment exit microconstant (k31), the elimination rate constant (k(el)), and the area under the concentration-time curve from 0 to 480 h (AUC0-480) (0.21-, 0.60-, 0.26-, 0.27-, 0.72-, and 0.76-fold, respectively; P < 0.05) but increased the volume of distribution at steady state (Vss), the volume of distribution calculated by the area method (V(area)), the apparent volume of the peripheral compartment (Vp), and all mean time parameters. These results suggested that poly-L-aspartic acid increased the distribution of gentamicin to or binding within the deep peripheral compartment and that poly-L-aspartic acid may have delayed gentamicin transit through the peripheral tissues. In contrast, poly-L-aspartic acid did not alter pharmacokinetic parameters relevant to the central or shallow peripheral compartments to a clinically significant extent. Although gentamicin's pharmacokinetic parameters of relevance to therapeutic drug monitoring were not directly altered, this study has provided pharmacokinetic evidence that poly-L-aspartic acid alters the peripheral distribution of gentamicin. This pharmacokinetic interaction occurred after a single intravenous dose of each drug. Therefore, this interaction should be investigated further, before polyaspartic acid can be considered for use as a clinical nephroprotectant.


1985 ◽  
Vol 106 (3) ◽  
pp. 269-273 ◽  
Author(s):  
D. G. Armstrong

ABSTRACT The object of this study was to examine changes in the activity of granulosa 3β-hydroxy-Δ5-steroid dehydrogenase during the ovulatory cycle of the domestic fowl. The enzyme activity in granulosa tissue from the largest follicle increased significantly during the period 8–14 h before an expected ovulation. The increase in activity occurs before the preovulatory surge of LH and near the time of lights off. During the 4–8 h period before an ovulation, i.e. the time of maximal plasma LH concentrations, 3β-hydroxy-Δ5-steroid dehydrogenase activity decreased in granulosa tissue from the largest follicle. This observation is explained by proposing that the enzyme is inhibited by the large amounts of progesterone found in the tissue at this time. The results indicate that important biochemical changes are taking place within granulosa tissue of the largest ovarian follicle before the preovulatory LH surge. J. Endocr. (1985) 106, 269–273


PEDIATRICS ◽  
1981 ◽  
Vol 68 (4) ◽  
pp. 601-602
Author(s):  
M. Spino ◽  
J. J. Thiessen ◽  
A. Isles ◽  
H. Levison ◽  
S. M. MacLeod

We found the report by Feldman et al1 interesting with potential clinical application. However, we would like to point out an error in their determination of the apparent volume of distribution (V) and comment on both their methodology and results. They state that V was calculated by dividing the dose of the drug by the extrapolated y intercept for drug concentration at time 0. This method is correct for a drug which exhibits monoexponential elimination following a single intravenous dose.


1935 ◽  
Vol 31 (11-12) ◽  
pp. 1325-1337
Author(s):  
E. R. Mogilevsky

If we consider the commanding position which the pituitary gland according to modern views occupies in the system of endocrine glands, and compare this with the role which many endocrine glands play in metabolism, then numerous attempts to isolate from the pituitary gland special hormones regulating metabolism will be completely understandable and natural. The search for special metabolic hormones in the pituitary gland is all the more justified because a number of clinical facts have directly suggested the involvement of the pituitary gland in metabolism.


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