Related Experiment Video
Updated: Jul 21, 2026

Isolation of Primary Mouse Hepatocytes for Nascent Protein Synthesis Analysis by Non-radioactive L-azidohomoalanine Labeling Method
Published on: October 23, 2018
Age effect on fibrinogen and albumin synthesis in humans
1Division of Endocrinology, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA.
Abstract:
A strong association has been reported between atherosclerotic diseases and fibrinogen levels, and a decreased whole body protein synthesis has also been reported with aging. We investigated the effect of age on fractional synthesis rates (FSR) of fibrinogen and albumin in 12 human subjects of young (20-30 yr), middle (45-60 yr), and old (65-79 yr) age by use of L-[1-13C]leucine and L-[15N]phenylalanine as tracers. An age-related decline in FSR of fibrinogen (P < 0.01) was observed with use of both tracers, with the maximal decrease (average 37% with alpha-[13C]ketoisocaproate as the precursor) occurring by middle age and with no further changes thereafter. In contrast, plasma concentrations of fibrinogen increased with age (P < 0.002). There was no age-related change in synthesis rate and concentrations of albumin. An age-related decline in fibrinogen FSR, but not FSR of albumin, indicates a differential effect of age on synthesis rate of these two liver proteins. This study also demonstrated that the increased circulating levels of fibrinogen represent a slower rate of disposal of fibrinogen rather than an increased production rate.
Related Concept Videos
Bone Disorders
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
Drug Distribution: Plasma Protein Binding
Factors Affecting Protein-Drug Binding: Protein-Related Factors
The physicochemical properties of a drug play a significant role in its ability to bind to proteins. Lipophilic drugs, which dissolve in fats, oils, and lipids, can be bound by...
Factors Affecting Protein-Drug Binding: Patient-Related Factors
Age stands as a key determinant in protein-drug binding. Neonates, characterized by low albumin content, experience heightened concentrations of unbound drugs such as phenytoin and...
Pharmacokinetics in Geriatric Patients: Effect of Age on Drug Distribution
Pharmacokinetics in Geriatric Patients: Effect of Age on Drug Excretion

