726. Histological changes in the mammary gland of guinea-pigs during lactation

1958 ◽  
Vol 25 (3) ◽  
pp. 392-396 ◽  
Author(s):  
M. Naito
Keyword(s):  
Mammary Gland ◽  
Dna Content ◽  
Guinea Pigs ◽  
Dry Weight ◽  
Histological Changes ◽  
Opposite Trend ◽  
Histological Factors ◽  
Porosity Index ◽  
Number Of Cells

Certain histological factors of the mammary gland and the DNA content unit per dry weight were studied at four stages of lactation in guinea-pigs.The porosity index, the number of alveoli per field, the number of cells per field and the DNA content, showed maximal values at parturition and minimal values at the peak of lactation, whereas the opposite trend was shown by the value for modal alveolar diameter and the number of cells per modal alveolus.The relationships between these results are discussed.

scholarly journals THE PATHOLOGIC EFFECTS OF STREPTOCOCCI FROM CASES OF POLIOMYELITIS AND OTHER SOURCES

1917 ◽  
Vol 25 (4) ◽  
pp. 557-580 ◽  
Author(s):  
Carroll G. Bull
Keyword(s):  
Spinal Cord ◽  
Guinea Pigs ◽  
The Other ◽  
Laboratory Animals ◽  
Histological Changes ◽  
Other Hand ◽  
Brain And Spinal Cord ◽  
The Brain

Streptococci cultivated from the tonsils of thirty-two cases of poliomyelitis were used to inoculate various laboratory animals. In no case was a condition induced resembling poliomyelitis clinically or pathologically in guinea pigs, dogs, cats, rabbits, or monkeys. On the other hand, a considerable percentage of the rabbits and a smaller percentage of some of the other animals developed lesions due to streptococci. These lesions consisted of meningitis, meningo-encephalitis, abscess of the brain, arthritis, tenosynovitis, myositis, abscess of the kidney, endocarditis, pericarditis, and neuritis. No distinction in the character or frequency of the lesions could be determined between the streptococci derived from poliomyelitic patients and from other sources. Streptococci isolated from the poliomyelitic brain and spinal cord of monkeys which succumbed to inoculation with the filtered virus failed to induce in monkeys any paralysis or the characteristic histological changes of poliomyelitis. These streptococci are regarded as secondary bacterial invaders of the nervous organs. Monkeys which have recovered from infection with streptococci derived from cases of poliomyelitis are not protected from infection with the filtered virus, and their blood does not neutralize the filtered virus in vitro. We have failed to detect any etiologic or pathologic relationship between streptococci and epidemic poliomyelitis in man or true experimental poliomyelitis in the monkey.

THE IN VITRO METABOLISM OF MAMMARY GLAND SLICES IN THE PRESENCE OF POSTERIOR PITUITARY LOBE EXTRACTS RICH IN MELANOPHORE-DISPERSING ACTIVITY

1957 ◽  
Vol 15 (4) ◽  
pp. 366-373 ◽  
Author(s):  
T. R. BRADLEY ◽  
G. M. MITCHELL
Keyword(s):  
Mammary Gland ◽  
Guinea Pigs ◽  
Incubation Medium ◽  
Mammary Glands ◽  
Gas Evolution ◽  
Early Lactation ◽  
Posterior Pituitary ◽  
Rats And Mice ◽  
Posterior Pituitary Lobe

SUMMARY Slices cut from mammary glands of rats and mice during gestation and lactation were incubated in vitro in the presence of pig posterior pituitary lobe extracts rich in melanophore-dispersing ('B') activity. Slices taken in early lactation but not during gestation or late lactation showed increased net gas evolution compared with control slices. Similar tissue from rabbits and guinea-pigs did not give rise to this effect, nor did slices of other tissues taken from lactating rats. The increased net gas evolution was not observed in the absence of glucose from the incubation medium. Treatment of the 'B' extract with NaOH or hypophysectomy of the rats prior to use decreased the response.

Growth hormone and mammary gland lobule-alveolar development

1961 ◽  
Vol 201 (2) ◽  
pp. 259-263 ◽  
Author(s):  
Richard C. Moon
Keyword(s):  
Growth Hormone ◽  
Mammary Gland ◽  
Dna Content ◽  
Deoxyribonucleic Acid ◽  
Cellular Proliferation ◽  
Estradiol Benzoate ◽  
The Mean ◽  
Alveolar Formation ◽  
Inguinal Glands ◽  
Range Of Values

The effect of growth hormone on mammary gland lobule-alveolar growth in the ovariectomized rat was studied using deoxyribonucleic acid (DNA) of the abdominal-inguinal glands as an index of the degree of cellular proliferation. The administration of 1 mg growth hormone in combination with 2 µg estradiol benzoate for 19 days resulted in alveolar formation and an increase in mammary DNA content above that resulting from injections of either hormone alone. The mean DNA concentration of glands of rats treated with 2 µg estradiol, 6 mg progesterone, 3 µg/100 g l-thyroxine, and 0.5, 1.0, 1.5, and 2.0 mg growth hormone was significantly greater than that of animals receiving only the estradiol, progesterone, and thyroxine. The increase in the mean DNA content was due to a shift in the range of values to a higher plane and did not result from an elevated DNA in only a few animals. It is suggested that the administration of growth hormone during the growth phase of the mammary gland may have a beneficial effect on the subsequent lactation.

Reduction of Carnitine Content by Inhibition of Its Biosynthesis Results in Protection of Isolated Guinea Pig Hearts against Hypoxic Damage

1996 ◽  
Vol 1 (3) ◽  
pp. 235-242 ◽  
Author(s):  
Pradip K. Dhar ◽  
Ingrid L. Grupp ◽  
Arnold Schwartz ◽  
Gunter Grupp ◽  
Mohammed A. Matlib
Keyword(s):  
Guinea Pigs ◽  
Initial Rate ◽  
Diastolic Pressure ◽  
Contractile Function ◽  
Dry Weight ◽  
Treated Group ◽  
Left Ventricular ◽  
Untreated Group ◽  
Free Carnitine ◽  
Isolated Hearts

Background 3-(2,2,2-trimethylhydrazinium) propionate (THP or mildronate) is an inhibitor of carnitine biosynthesis. This study was carried out to determine whether feeding of guinea pigs with THP results in decreased myocardial-free carnitine content and, as a result, attenuates hypoxic damage in isolated and paced work-performing hearts. Methods and Results Guinea pigs were administered either distilled water or 100 mg THP/kg/day orally for 10 days. The treatment resulted in about a 50% decline in myocardial-free carnitine content, from 11.1 ± 0.2 (n = 5) to 5.6 ± 0.2 (n = 5) μM/g dry weight of the heart. The left ventricular contractile function of the hearts was measured during normoxic perfusion (PO2 = 590 mmHg), hypoxic perfusion (PO2 = 149 mmHg), and reperfusion (PO2 = 590 mmHg). In both untreated and THP-treated groups, the rate of development of intraventricular pressure (+dP/dt) under normoxic perfusion was similar; however, +dP/dt declined to about 10% of the initial rate within 20 minutes of hypoxic perfusion. In the THP-treated group of hearts, the initial decline was slower than that of the untreated animal hearts. After 20 minutes of normoxic reperfusion following 60 minutes of hypoxic perfusion, the recovery of +dP/dt and -dP/dt was greater in the THP-treated group than in the untreated group. The elevation of end-diastolic pressure during hypoxia was completely reversed by normoxic reperfusion of the THP-treated group but not in the untreated group. Mitochondria isolated from hearts from the THP-treated group after normoxic reperfusion following hypoxic perfusion exhibited better respiratory function than those from untreated hearts. Conclusion The data suggest that feeding guinea pigs with THP results in reduced myocardial-free carnitine content and attenuation of hypoxic and reperfusion injury in isolated hearts.

Attenuation of hyperoxic lung injury by the 21-aminosteroid U-74389G

1995 ◽  
Vol 78 (5) ◽  
pp. 1635-1641 ◽  
Author(s):  
S. Tasaka ◽  
A. Ishizaka ◽  
T. Urano ◽  
K. Sayama ◽  
F. Sakamaki ◽  
...  
Keyword(s):  
Lung Injury ◽  
Lung Tissue ◽  
Guinea Pigs ◽  
Weight Ratio ◽  
Dry Weight ◽  
Endothelial Damage ◽  
Lung Water ◽  
Tissue Samples ◽  
Cell Accumulation ◽  
Hyperoxic Lung Injury

Hyperoxic lung injury is attributable to oxygen radicals produced under hyperoxic conditions. The 21-aminosteroid (AS), U-74389G, is a potent antioxidant. We examined the effect of U-74389G on lung injury in guinea pigs during exposure to 90% O2 for 48 h. We injected either vehicle or 10 mg/kg of U-74389G 30 min before the O2 exposure and injected the same dose 12, 24, and 36 h later. We performed two series of experiments after exposure. In the first series, we measured the clearance rate of 99mTc-labeled dialdehyde starch (DAS) from the lungs as an index of pulmonary epithelial damage in three experimental groups consisting of 1) control (n = 6) O2 alone (n = 6), and 3) O2 + AS (n = 6). In the second series, pulmonary endothelial injury was estimated by using 28 guinea pigs divided into four experimental groups consisting of 1) control (n = 8), 2) AS alone (n = 5), 3) O2 alone (n = 6), and 4) O2 + AS (n = 9). In the second series, we measured the wet-to-dry weight ratio (W/D) as an index of lung water and the concentration ratio of 125I-labeled albumin in lung tissue and bronchoalveolar lavage (BAL) fluid compared with plasma (T/P and BAL/P, respectively) as indexes of pulmonary endothelial damage. Cell accumulation in BAL fluid and lung tissue samples was also assessed in the second series.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

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