摘要:

Plasma levels of thyroxine (T4), triiodothyronine (T3) and growth hormone (GH) as well as the free T4 and free T3 index (FT4I, FT3I) in 20-month-old female Syrian hamsters kept under long daily photoperiod [light:dark (LD) cycles of 14:10] were significantly depressed compared to the values of 2-month-old animals kept under the same photoperiodic conditions. Cholesterol levels in old females were significantly elevated compared to those in young animals. In a subsequent experiment, young (4 month) and old (15 month) female hamsters were either placed in a short photoperiod (10:14 LD) or a 14:10 LD cycle and given daily afternoon injection of either diluent or 25 μg melatonin. After 8 weeks, the old females, regardless of treatment or photoperiod, had significantly lower T4 levels and higher cholesterol and triglyceride levels than did young animals. In 14:10 LD, FT4I and FT3I did not differ between young and old animals, possibly because of the reduced age gap in this experiment. Although the FT4I and FT3I in young females after 8 weeks of treatment with 10:14 LD or melatonin were not significant, the old females did demonstrate a significant suppression of their FT4I and FT3I values

ISSN:0304-324X    

DOI:10.1159/000212555

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Morphological changes in rat heart mitochondria following mobilization of the adenine nucleotide binding sites from the matrix to the cytosolic face of the inner membrane have been documented in this paper by means of electron microscopy. Significant differences in the shape of cristae membranes could be established when rat heart mitochondria from 3-and 30-month-old animals were compared. Changes in structural organization of the inner membrane – an event associated with the function of the adenine nucleotide carrier – were found to be distinctly less marked in mitochondria from the aged group. Kinetic analysis of this process revealed that both the velocity and the extent of conformational membrane changes were reduced as the animal ages. These observations are discussed in relation to the finding, also described in this paper, that aging is linked to a drastic decrease in the activity of adenosine diphosphate/adenosine triphosphate excha

ISSN:0304-324X    

DOI:10.1159/000212556

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

We have studied the age-related modifications of endogenous phosphorylations and protein kinases in seven different strains of cultured human cells (two fibroblastic and five human liver-derived strains). Endogenous phosphorylation of phosphopeptides by cells incubated in the presence of [32P]orthophosphate constantly changed with aging; these modifications could not be explained only by loss of replicative capacity of these cells. Total casein and phosvitin kinase activity did not change in the course of in vitro cell aging. Gel filtration chromatography and autophosphorylation of partially purified kinase preparations, however, seemed to indicate some age-related modifications of protein kinases. Electrophoresis of active enzymes demonstrated that some histone/protamine kinases decreased with aging while a new 3′:5′-cyclic AMP-independent histone kinase band appeared progressively. It is proposed that new protein kinase isozymes could correspond to new genes progressively activated during cell aging and could be closely related to cell senescence and de

ISSN:0304-324X    

DOI:10.1159/000212557

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

The specific [3H]-dexamethasone binding ability of the cytosols of divergent tissues such as kidney, testis and heart were examined in adult (2- to 3-month-old) as well as in senescent (20- to 24-month-old) male adrenalectomized Sprague-Dawley rats. Scatchard analysis showed the presence of a single class of high affinity binding sites in all these tissues from both adult and aged animals. No significant age-related changes in receptor binding site concentration, affinity or steroid specifities were apparent in either kidney, testis or heart. In addition, no age-related changes were observed in in vivo or in vitro nuclear binding of the [3H]-dexamethasone-receptor complexes in all the tissues examined. It was concluded that aging does not alter glucocorticoid receptor concentration, affinity or its ability to bind to nuclei in these diverse tissues examined.

ISSN:0304-324X    

DOI:10.1159/000212558

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Cerebrospinal fluid (CSF) lactate and age were examined in a group of 64 volunteers (44 normals and 20 depressives). Correlations between CSF lactate and age were significant for both separate and combined groups. Increased CSF lactate with age may reflect an impairment of central nervous system glucose metabolism. The authors suggest additional biogenic amine parameters which might be examined in order to differentiate metabolic changes related to aging and dementia from those which may be specific to depressive disorders.

ISSN:0304-324X    

DOI:10.1159/000212559

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

Serum Lp(a) levels have been measured in a family kindred of three generations by Laurell electrophoresis. It was found that individuals with Lp(a) levels exceeding 30 mg/dl exhibited an extra pre-beta-band in agarose gel electrophoresis (sinking pre-beta positive), and a significant positive correlation existed between serum Lp(a) levels and age. A positive correlation between Lp(a) and total serum cholesterol was observed only in sinking pre-beta-positive individuals, but not in sinking pre-β-negative individuals with Lp(a) levels of less than 30 mg/dl. These findings are not contradictory to the assumption that Lp(a) might be an independent rise factor for atherosclerosis

ISSN:0304-324X    

DOI:10.1159/000212560

出版商:S. Karger AG    

年代:1982

数据来源: Karger

摘要:

In a cross-sectional study, the amylase to creatinine clearance ratio (ACCR) was determined in 180 patients, age range 18–93 years. An inverse correlation was found between ACCR and creatinine clearance (r = ––0.40, p < 0.001) in keeping with the known inverse relationship between the sieving fraction of macromolecules and the glomerular filtration rate. The fractional clearance of amylase was not significantly affected by amylasemia nor by age when the creatinine clearance was also considered in a multiple regression analysis. No increase in ACCR was observed in patients with low molecular weight proteinuria or with induced urine dilution. The authors assume that the tubular reabsorption of amylase is minimal and that the enhancement of ACCR in the elderly mainly reflects modifications in the glomerular filtration dyn

ISSN:0304-324X    

DOI:10.1159/000212561

出版商:S. Karger AG    

年代:1982

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000212562

出版商:S. Karger AG    

年代:1982

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000212563

出版商:S. Karger AG    

年代:1982

数据来源: Karger

ISSN:0304-324X    

DOI:10.1159/000212564

出版商:S. Karger AG    

年代:1982

数据来源: Karger