EFFECT OF RESERPINE ON PITUITARY PROLACTIN CONTENT AND ITS HYPOTHALAMIC SITE OF ACTION IN THE RABBIT

1963 ◽  
Vol 44 (3) ◽  
pp. 467-474 ◽  
Author(s):  
S. Kanematsu ◽  
J. Hilliard ◽  
C. H. Sawyer
Keyword(s):  
Mammary Gland ◽  
Pituitary Gland ◽  
Intravenous Dose ◽  
Electrolytic Lesion ◽  
Single Intravenous Dose ◽  
Site Of Action ◽  
Prolactin Content ◽  
Pituitary Prolactin

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.

PROLACTIN RELEASE IN PARENT RING DOVES AFTER BRIEF EXPOSURE TO THEIR YOUNG

1979 ◽  
Vol 82 (1) ◽  
pp. 127-130 ◽  
Author(s):  
J. D. BUNTIN
Keyword(s):  
Sex Differences ◽  
Pituitary Gland ◽  
Environmental Regulation ◽  
Prolactin Secretion ◽  
Radioreceptor Assay ◽  
Prolactin Release ◽  
The Third ◽  
Prolactin Content ◽  
Pituitary Prolactin ◽  
Ring Doves

SUMMARY A pigeon crop sac radioreceptor assay was used to measure changes in pituitary prolactin levels in parent ring doves of both sexes on the third day after hatching of their young. After a deprivation of 17 h from the squabs, exposure to a 3-day-old squab for 1 h resulted in a significant decrease in the prolactin content of the pituitary gland as compared with levels obtained in control birds deprived of their young for 18 h. No significant sex differences in prolactin levels were observed in either group. Because exposure to the young also promotes prolactin-induced crop sac growth, it appears probable that the squab-induced decrease in prolactin content of the pituitary gland reflects the release of prolactin into the circulation. Accordingly, the environmental regulation of prolactin secretion in parent ring doves appears similar to that observed in lactating mammals.

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
Keyword(s):  
Pituitary Gland ◽  
Domestic Fowl ◽  
Intravenous Dose ◽  
Single Intravenous Dose ◽  
Ovulatory Cycle ◽  
Wet Weight

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.

PROLACTIN CONTENT OF CANINE PITUITARY GLAND

1973 ◽  
Vol 57 (3) ◽  
pp. 495-500 ◽  
Author(s):  
P. G. SALUJA ◽  
J. M. HAMILTON ◽  
M. GRONOW
Keyword(s):  
Pituitary Gland ◽  
Isoelectric Focusing ◽  
Reproductive Cycle ◽  
Post Partum ◽  
Oestrous Cycle ◽  
Polyacrylamide Gels ◽  
Prolactin Content ◽  
High Concentrations ◽  
Pituitary Prolactin ◽  
Good Agreement

SUMMARY The prolactin concentration in the dog pituitary gland was determined by isoelectric focusing of adenohypophysial extract in polyacrylamide gels followed by densitometry of the isolated stained hormone band. Dogs of both sexes and various ages (excluding newborn pups and weanlings) were studied. The bitches comprised animals at different stages of the oestrous cycle and also included a small number of pregnant, lactating or ovariectomized animals. Low pituitary prolactin concentrations were found in males, sexually immature females and dioestrous females. Concentrations about 1·5 times as high occurred in oestrous, metoestrous (luteal) and ovariectomized females. Post-partum lactating bitches had the highest pituitary prolactin concentrations, these being double those occurring at dioestrus. With the exception of relatively high concentrations in ovariectomized bitches, these results are in good agreement with findings in the rat, mouse and rabbit. The persistence of high pituitary prolactin levels throughout metoestrus was believed to be associated with differences between the canine and murine reproductive cycle. Age did not influence pituitary prolactin levels in either males or females.

Cytopathology of Cardiac Tissue from Daunomycin-Treated Mice

1971 ◽  
Vol 29 ◽  
pp. 550-551
Author(s):  
Robert H. Liss ◽  
Frances A. Cotton
Keyword(s):  
Cardiac Tissue ◽  
Cardiac Toxicity ◽  
Drug Distribution ◽  
Personal Communication ◽  
Intravenous Dose ◽  
Single Intravenous Dose ◽  
Physiologic Saline ◽  
Histopathologic Changes ◽  
Distribution Studies ◽  
Lung And Kidney

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.

THE EXTRACTION OF PROLACTIN FROM HUMAN PITUITARY GLANDS

1965 ◽  
Vol 49 (1) ◽  
pp. 1-16 ◽  
Author(s):  
M. Apostolakis
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
List Type ◽  
Distilled Water ◽  
Hormone Activity ◽  
Isoelectric Precipitation ◽  
Human Pituitary ◽  
Pituitary Glands ◽  
Prolactin Content ◽  
The Mean

ABSTRACT A method for the extraction of prolactin from human pituitary glands is described. It is based on acetone drying, distilled water extraction, acetone and isoelectric precipitation. Two main products are obtained: Fraction R8 with a mean prolactin activity of 12.2 IU/mg and fraction U8 with a mean prolactin activity of 8.6 IU/mg. The former fraction does not contain any significant gonadotrophin activity and the latter contains on an average 50 HMG U/mg. In both cases contamination with ACTH and MSH is minimal. The growth hormone activity of both these fractions is low. It is postulated that in man too, prolactin and growth hormone are two distinct hormones. A total of 1250 human pituitary glands have been processed by this method. The mean prolactin content per pituitary gland has been found to be 73 IU.

scholarly journals Effect of polyaspartic acid on pharmacokinetics of gentamicin after single intravenous dose in the dog.

1996 ◽  
Vol 40 (5) ◽  
pp. 1237-1241 ◽  
Author(s):  
T Whittem ◽  
K Parton ◽  
K Turner
Keyword(s):  
Aspartic Acid ◽  
Elimination Rate ◽  
Volume Of Distribution ◽  
Intravenous Dose ◽  
Pharmacokinetic Parameters ◽  
Therapeutic Drug ◽  
Peripheral Compartment ◽  
Single Intravenous Dose ◽  
Polyaspartic Acid ◽  
Peripheral Tissues

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.

Letters to the Editor

PEDIATRICS ◽  
1981 ◽  
Vol 68 (4) ◽  
pp. 601-602
Author(s):  
M. Spino ◽  
J. J. Thiessen ◽  
A. Isles ◽  
H. Levison ◽  
S. M. MacLeod
Keyword(s):  
Clinical Application ◽  
Drug Concentration ◽  
Apparent Volume ◽  
Volume Of Distribution ◽  
Intravenous Dose ◽  
Single Intravenous Dose ◽  
Letters To The Editor ◽  
Potential Clinical Application ◽  
Apparent Volume Of Distribution

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.

A double-blind trial of a single intravenous dose of metronidazole as prophylaxis against wound infection following appendicectomy

1979 ◽  
Vol 66 (6) ◽  
pp. 428-429 ◽  
Author(s):  
M. J. Greenall ◽  
A. Bakran ◽  
I. R. Pickford ◽  
J. A. Bradley ◽  
A. Halsall ◽  
...  
Keyword(s):  
Wound Infection ◽  
Intravenous Dose ◽  
Double Blind Trial ◽  
Single Intravenous Dose ◽  
Double Blind ◽  
Blind Trial
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