THE EFFECT OF OESTRONE ON THE MAMMARY GLAND OF ADRENALECTOMIZED GUINEA-PIGS

1957 ◽  
Vol 16 (2) ◽  
pp. 227-NP ◽  
Author(s):  
E. O. HÖHN
Keyword(s):  
Mammary Gland ◽  
Guinea Pig ◽  
Adrenal Cortex ◽  
Guinea Pigs ◽  
Growth Response ◽  
Alcoholic Solution ◽  
Survival Period ◽  
Alveolar Development ◽  
Average Survival

SUMMARY In the guinea-pig progesterone is not required for alveolar development of the mammary gland. In order to test the hypothesis that this can be accounted for by endogenous progesterone produced by the adrenal cortex in this species, the growth response of the mammary gland to oestrone of adrenalectomized castrated male guinea-pigs has been studied. Oestrone applied to the nipples as an alcoholic solution in doses of 15 μg/day for 14 days resulted in the formation of clusters of mammary alveoli in animals subjected merely to castration. In eleven castrated and adrenalectomized animals which survived oestrone treatment for periods of 11–28 days only duct proliferation with occasional formation of isolated alveoli was observed. Nipple growth in response to oestrone, as indicated by changes in nipple length, was much the same in both groups. Administration of oestrone to adrenalectomized animals was found to be toxic. The average survival of oestrone-treated, adrenalectomized castrated animals was only 4 days, compared with an average survival period of 16·6 days in similar animals not treated with oestrone.

Respiratory Metabolism During Pregnancy in the Guinea Pig

1957 ◽  
Vol 190 (3) ◽  
pp. 425-428 ◽  
Author(s):  
Richard M. Hoar ◽  
William C. Young
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Guinea Pig ◽  
Metabolic Rate ◽  
Adrenal Cortex ◽  
Guinea Pigs ◽  
Sharp Decrease ◽  
Zona Fasciculata ◽  
Respiratory Metabolism ◽  
Morphological Differences

Oxygen consumption and heart rate during pregnancy were measured in untreated, thyroxin-injected and thyroidectomized guinea pigs given I131. From impregnation until parturition, oxygen consumption increased 7.9% in untreated females. The increase continued until 5 days postpartum when a sharp decrease occurred. The increase is not accounted for by growth of the fetal mass. Comparable increases occurred in thyroxin-injected (16.2%) and thyroidectomized (11.9%) females, although the levels throughout were higher and lower, respectively, than in intact females. Heart rate did not increase. On the contrary, statistically significant decreases occurred in the untreated and thyroxin-injected females. Although the mechanism associated with the increased metabolic rate is not known, the possibility of thyroid participation would seem to be excluded. Involvement of the adrenal cortex is suggested by morphological differences in the cells of the zona fasciculata in pregnant and nonpregnant females and by evidence cited from other studies.

scholarly journals The protein-synthesizing activity of ribosomes isolated from the mammary gland of lactating and pregnant guinea pigs

1971 ◽  
Vol 123 (5) ◽  
pp. 865-874 ◽  
Author(s):  
E. Fairhurst ◽  
Diana McIlreavy ◽  
P. N. Campbell
Keyword(s):  
Protein Synthesis ◽  
Mammary Gland ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Cyanogen Bromide ◽  
Mammary Glands

1. Polyribosome preparations were made from the deoxycholate-treated post-nuclear fractions obtained by the disruption of mammary glands from lactating and pregnant guinea pigs. 2. A high proportion of large polyribosomes was obtained from the glands of lactating animals whereas mainly small polyribosomes were obtained from the glands of pregnant animals. The isolated preparations incorporated [14C]phenylalanine into protein. The polyribosomes from the glands of pregnant animals were less active than those from the glands of lactating animals but the activity of the former was stimulated more by poly(U) than was the latter. 3. The ribosomes from mammary gland could be dissociated into subunits after incubation, under conditions necessary for protein synthesis, in the presence of puromycin. The subunits could be recombined to give a preparation that actively polymerized [14C]phenylalanine in the presence of poly(U). The subunits from guinea-pig mammary gland could be combined with subunits from liver of either guinea pig or rat. Hybrid ribosomes were also formed from subunits derived from glands of pregnant and lactating animals. The hybrids were as active as were the ribosomes formed by reassociation of subunits from the same tissue, suggesting that in this respect the ribosomes from pregnant animals were not defective. 4. Polyribosomes from mammary glands of lactating animals when incubated with cell sap from the same source were tested for their ability to synthesize α-lactalbumin. The polyribosomes were incubated in the presence of [3H]leucine and α-lactalbumin was isolated from the supernatant. The protein was finally treated with cyanogen bromide and the C-terminal and N-terminal fragments were separated and their radioactivity was determined. Both fragments were radioactive consistent with the synthesis of α-lactalbumin. 5. The results are discussed in relation to protein synthesis in the mammary gland after parturition.

EFFECTS OF OESTRONE AND PROGESTERONE ON MAMMARY DEVELOPMENT IN THE GUINEA-PIG

1957 ◽  
Vol 15 (2) ◽  
pp. 126-NP ◽  
Author(s):  
G. K. BENSON ◽  
A. T. COWIE ◽  
C. P. COX ◽  
S. A. GOLDZVEIG
Keyword(s):  
Mammary Gland ◽  
Guinea Pig ◽  
Synergistic Effects ◽  
Dose Range ◽  
Mammary Development ◽  
Factorial Designs ◽  
Alveolar Development ◽  
Daily Dose ◽  
Cystic Changes ◽  
Dose Levels

SUMMARY Three experiments are described on the effects of oestrone and progesterone over wide dose ranges on the development of the mammary gland in the ovariectomized guinea-pig. Factorial designs were used so that the responses to both steroids could be studied simultaneously. The degree of mammary development was assessed by objective and by subjective methods. The observation of previous workers that complete mammary development could be evoked in the guinea-pig by oestrogen alone was not confirmed. Over a wide dose range of oestrone better development of the gland was obtained if progesterone was also administered. On some dose levels of oestrone the synergistic effects of progesterone were very marked. Maximal mammary development was observed with a daily dose of 10–50 μg oestrone in combination with 1000 μg progesterone. Considerable lobule-alveolar development was observed with progesterone alone when the daily dose was sufficiently high (2400 μg). No histological abnormalities were observed in the glands except in those developed on the lowest dose of oestrone to give significant growth effects (0·1 μg), in which there was some evidence of cystic changes. The significance of the progesterone: oestrogen ratio in mammary development is discussed.

scholarly journals Esterification of glycerol 3-phosphate in lactating guinea-pig mammary gland

1967 ◽  
Vol 105 (1) ◽  
pp. 213-223 ◽  
Author(s):  
N. J. Kuhn
Keyword(s):  
Mammary Gland ◽  
Guinea Pig ◽  
Phosphatidic Acid ◽  
Guinea Pigs ◽  
Particulate Fraction ◽  
Mammary Tissue ◽  
Acyl Donor ◽  
Free System ◽  
Kennedy Pathway ◽  
A Cell

1. The presence of palmitoyl-CoA–l-glycerol 3-phosphate palmitoyltransferase (EC 2.3.1.15) has been demonstrated in a particulate fraction of mammary tissue from lactating guinea pigs. 2. Cell-free preparations also catalysed the activation of palmitate and oleate, and the conversion of enzymically formed phosphatidic acid into glycerides, in accord with the Kennedy pathway of glyceride formation. 3. The properties of the system that esterifies l-glycerol 3-phosphate were studied with respect to substrates and cofactors, and the reaction product was shown to be phosphatidic acid (1,2-diacyl glycerol 3-phosphate). 4. The extent to which newly formed phosphatidic acid was converted into glyceride in a cell-free system was dependent on the nature of the acyl donor, the concentration of subcellular particles, the time of incubation and the concentration of Mg2+.

EFFECTS OF EXOGENOUS CORTISOL ON THE UPTAKE OF CORTICOSTEROIDS BY THE ISOLATED PERFUSED GUINEA-PIG MAMMARY GLAND

1979 ◽  
Vol 80 (3) ◽  
pp. 357-364 ◽  
Author(s):  
A. R. PETERS ◽  
T. B. MEPHAM
Keyword(s):  
Mammary Gland ◽  
Guinea Pig ◽  
Guinea Pigs ◽  
Convincing Evidence ◽  
The Mean

Assay of corticosteroids in the plasma of guinea-pigs showed that concentrations were higher in lactating than in non-lactating and male animals. In five isolated perfused mammary gland experiments in which corticosteroids were at concentrations of 1·3–3·0 μg/ml in the perfusate, equivalent to concentrations during lactation, the mean (±s.e.m.) uptake by the mammary gland was 900 ± 210 ng g−1 h−1. In five experiments in which the concentrations of corticosteroid in the perfusate were 190–580 ng/ml, the uptake by the mammary gland was significantly lower (316 ± 73 ng g−1 h−1; P < 0·05). For the ten experiments there was a significant correlation between the concentration of corticosteroid in the perfusate and uptake by the mammary gland (P < 0·05). No convincing evidence for a galactopoietic role of corticosteroids in the guinea-pig was obtained, although administration of cortisol significantly stimulated the uptake of glutamine by the perfused gland.

Glycogen in guinea pig neutrophils: Ultrastructural study of neutrophils at the intradermal site of BCG injection

1983 ◽  
Vol 41 ◽  
pp. 726-727
Author(s):  
Corazon D. Bucana
Keyword(s):  
Bone Marrow ◽  
Guinea Pig ◽  
Electron Density ◽  
Peritoneal Cavity ◽  
Ultrastructural Study ◽  
Guinea Pigs ◽  
Random Distribution ◽  
Glycogen Content ◽  
Polymorphonuclear Neutrophils ◽  
Ultrastructural Studies

In the circulating blood of man and guinea pigs, glycogen occurs primarily in polymorphonuclear neutrophils and platelets. The amount of glycogen in neutrophils increases with time after the cells leave the bone marrow, and the distribution of glycogen in neutrophils changes from an apparently random distribution to large clumps when these cells move out of the circulation to the site of inflammation in the peritoneal cavity. The objective of this study was to further investigate changes in glycogen content and distribution in neutrophils. I chose an intradermal site because it allows study of neutrophils at various stages of extravasation.Initially, osmium ferrocyanide and osmium ferricyanide were used to fix glycogen in the neutrophils for ultrastructural studies. My findings confirmed previous reports that showed that glycogen is well preserved by both these fixatives and that osmium ferricyanide protects glycogen from solubilization by uranyl acetate.I found that osmium ferrocyanide similarly protected glycogen. My studies showed, however, that the electron density of mitochondria and other cytoplasmic organelles was lower in samples fixed with osmium ferrocyanide than in samples fixed with osmium ferricyanide.

Inhibition of Human and Animal Platelet Adhesiveness to Glass Bead Columns by Adenosine, Dipyridamole, Chlorpromazine and Acetylsalicylic Acid

1976 ◽  
Vol 36 (02) ◽  
pp. 401-410 ◽  
Author(s):  
Buichi Fujttani ◽  
Toshimichi Tsuboi ◽  
Kazuko Takeno ◽  
Kouichi Yoshida ◽  
Masanao Shimizu
Keyword(s):  
Guinea Pig ◽  
Acetylsalicylic Acid ◽  
Guinea Pigs ◽  
Glass Bead ◽  
Animal Species ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Platelet Adhesiveness

SummaryThe differences among human, rabbit and guinea-pig platelet adhesiveness as for inhibitions by adenosine, dipyridamole, chlorpromazine and acetylsalicylic acid are described, and the influence of measurement conditions on platelet adhesiveness is also reported. Platelet adhesiveness of human and animal species decreased with an increase of heparin concentrations and an increase of flow rate of blood passing through a glass bead column. Human and rabbit platelet adhesiveness was inhibited in vitro by adenosine, dipyridamole and chlorpromazine, but not by acetylsalicylic acid. On the other hand, guinea-pig platelet adhesiveness was inhibited by the four drugs including acetylsalicylic acid. In in vivo study, adenosine, dipyridamole and chlorpromazine inhibited platelet adhesiveness in rabbits and guinea-pigs. Acetylsalicylic acid showed the inhibitory effect in guinea-pigs, but not in rabbits.

INCORPORATION OF IODIDE INTO ORGANIC COMPOUNDS IN THE GUINEA PIG THYROID

1963 ◽  
Vol 43 (1) ◽  
pp. 110-118 ◽  
Author(s):  
R. Ekholm ◽  
T. Zelander ◽  
P.-S. Agrell
Keyword(s):  
Guinea Pig ◽  
Protein Binding ◽  
Organic Compounds ◽  
Guinea Pigs ◽  
Microsomal Fraction ◽  
Thyroid Tissue ◽  
Particulate Fraction ◽  
Supernatant Fraction ◽  
Hydrolysis Of

ABSTRACT Guinea pigs, kept on a iodine-sufficient diet, were injected with Na131I and the thyroids excised from 45 seconds to 5 days later. The thyroid tissue was homogenized and separated into a combined nuclear-mitochondrial-microsomal fraction and a supernatant fraction by centrifugation at 140 000 g for one hour. Protein bound 131iodine (PB131I) and free 131iodide were determined in the fractions and the PB131I was analysed for monoiodotyrosine (MIT), diiodotyrosine (DIT) and thyroxine after hydrolysis of PB131I. As early as only 20 minutes after the Na131I-injection almost 100% of the particulate fraction 131I was protein bound. In the supernatant fraction the protein binding was somewhat less rapid and PB131I values above 90% of total supernatant 131I were not found until 3 hours after the injection. In all experiments the total amount of PB131I was higher in the supernatant than in the corresponding particulate fraction. The ratio between supernatant PB131I and pellet PB131I was lower in experiments up to 3 minutes and from 2 to 5 days than in experiments of 6 minutes to 20 hours. Hydrolysis of PB131I yielded, even in the shortest experiments, both MIT and DIT. The DIT/MIT ratio was lower in the experiments up to 2 hours than in those of 3 hours and over.

Method for recording ECG's in unanesthetized guinea pigs

1965 ◽  
Vol 20 (5) ◽  
pp. 1091-1093 ◽  
Author(s):  
Alfred Richtarik ◽  
Thomas A. Woolsey ◽  
Enrique Valdivia
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Standing Posture ◽  
Factors Affecting ◽  
Rapid Succession ◽  
Unanesthetized Animals ◽  
Animal Size ◽  
Four Electrodes

A device for use in recording ECG's from guinea pigs is described. It is constructed of Plexiglas and consists of a base with four electrodes (separated by plastic ridges) on which the animal stands. The animal's activity is restricted by a removable box, the ends and top of which are adjustable to compensate for variations in animal size. The device permits recording of ECG's in rapid succession from quiet, unanesthetized animals in normal standing posture. Results obtained with the method are reported. apparatus for guinea pig ECG; time relations guinea pig ECG; normal ECG, guinea pig; factors affecting quality of ECG recordings from guinea pigs Submitted on October 21, 1964

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