摘要:

Electron-microscopic examination of aortas of rat treated orally and chronically with β-aminopropionitrile (BAPN) has shown progressive lesions in the elastic framework. This is associated with modifications of cells in the media which dedifferentiate into histiocytes and fibrocytes and also multiply. These changes begin in the 5th week of treatment, and are responsible for the hyperplasia of the intima as well as its thickening and collagenization. They support observations made in man during aortic aging, namely with regard to the intima and the intima-media junction. A high lipid diet given at various times during intoxication causes lipid deposition in the intima and a substantial penetration into the media when the lesions are developing. This also corroborates some hypotheses on the development of human atheroma. The addition of pyridinol carbamate (PDC) to BAPN prevents the formation of elastic tissue lesions. When given after the cessation of lathyrism treatment, PDC arrests and causes regression of lesions in the aortic media. It has no effects on lipid deposits, but the deposits are confined to the intima only

ISSN:0304-324X    

DOI:10.1159/000212016

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

The chemical composition has been determined in inner, middle and peripheral zones of 50 human knee joint menisci of ages 0–86 years. Of these, 12 showed areas of degeneration which were analysed separately. On a dry weight basis, normal adult tissues contained 77.9 ± 0.4% collagen, 8.1 ± 0.8% non-collagenous proteins (NCP) and 1.0 ± 0.1 % hexosamine. With aging, the level of collagen increases and NCP declines. In degenerate areas, a statistically significant loss in collagen, and rise in NCP and hexosamines was observed, relative to normal menisci of the same

ISSN:0304-324X    

DOI:10.1159/000212017

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

Plasma corticosterone levels were measured fluorometrically in male DBA/2J and C57BL/6J mice at various ages, under control conditions and after exposure to an open-field activity situation. Additionally, mice of the two strains were injected with varying doses of ACTH in order to observe the responsiveness of the aging adrenal. Results indicate a progressive and declining adrenal response to ACTH which is significantly more pronounced in DBA/2J than C57BL/6J mice. Exposure to the open-field situation revealed significantly higher reactivity of C57BL/6J than DBA/2J mice when compared to basal conditions. A number of hypotheses are offered for explaining the differences with advancing age in the two strains.

ISSN:0304-324X    

DOI:10.1159/000212018

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

Determinations were made of testes and seminal vesicle weights as well as plasma testosterone levels in aging male mice of inbred strains DBA/2J and C57BL/6J. Results indicate that plasma testosterone levels are significantly higher in C57BL/6J mice than in DBA/2J, although at 2 months of age the latter strain exhibited significantly higher levels than the former. Of significant interest is the finding that both strains did not exhibit any significant alteration in testosterone levels during their adult life except at 2 months of age. Seminal vesicle weights differed significantly between the two strains only at 20 and 28 months. Suggestion is further made that body weight correction for weight of organs, such as testes and seminal vesicles, may be inappropriate; rather, the most appropriate adjustment of these organ weights to correct for correlations with body weight may be covariance analysis.

ISSN:0304-324X    

DOI:10.1159/000212019

出版商:S. Karger AG    

年代:1974

数据来源: Karger

摘要:

In senile (28- to 36-month-old) rats prolongation of latency period, contraction and relaxation time in fast muscle is confirmed; however, there is a shortening of these time parameters in the slow soleus muscle. Ca2+-activated myosin ATPase activity decreases in fast but increases in the slow senile soleus muscle. A trend of levelling out of the differences between fast and slow muscles is thus observed in respect to speed of contraction and myosin ATPase activity.

ISSN:0304-324X    

DOI:10.1159/000212020

出版商:S. Karger AG    

年代:1974

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000212021

出版商:S. Karger AG    

年代:1974

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000212022

出版商:S. Karger AG    

年代:1974

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000212023

出版商:S. Karger AG    

年代:1974

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000212024

出版商:S. Karger AG    

年代:1974

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000212015

出版商:S. Karger AG    

年代:1974

数据来源: Karger