Urinary felinine excretion in intact male cats is increased by dietary cystine

Felinine is a branched-chain sulfur amino acid present in the urine of certain Felidae, including domestic cats. The objective of the present study was to determine if additional cystine and/or dietary N would increase felinine and N-acetylfelinine excretion by intact male cats fed a low-protein (LP) diet. Feeding five adult intact male cats an LP diet (18·8% of metabolisable energy (ME) as protein) v. a high-protein diet (38·6% of ME as protein) resulted in a trend (P¼0·08) for decreased urinary felinine and no change in N-acetylfelinine excretion. In a 23 d study, when the LP diet was supplemented with L-cystine at 9·3 g/kg DM, urinary felinine:creatinine ratio showed a linear two-fold (121 %) increase (P,0·01) from 0·24 (SEM 0·05) to 0·53 (SEM 0·13) after 10 d. Subsequent feeding of the LP diet resulted in a decrease in felinine excretion to base levels. Plasma gglutamylfelinylglycine concentrations were consistent with the excretion of felinine. Supplementation of the LP diet with L-cystine (9·3 g/kg DM), dispensable amino acids and arginine to a second group (n 5) also resulted in a significant (P,0·01) but smaller (þ72 %) increase in the daily felinine:creatinine ratio (0·25 (SEM 0·04) to 0·43 (SEM 0·05)). The degree of felinine N-acetylation within groups was unaffected by dietary addition and withdrawal of amino acids. The results indicate that felinine synthesis is regulated by cystine availability, and that arginine may be physiologically important in decreasing felinine biosynthesis in intact male cats

Comparison of Three Salivary Collection methods to Assess Physiological Markers.

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Bioactive Peptides from Muscle Sources: Meat and Fish

Bioactive peptides have been identified in a range of foods, including plant, milk and muscle, e.g., beef, chicken, pork and fish muscle proteins. Bioactive peptides from food proteins offer major potential for incorporation into functional foods and nutraceuticals. The aim of this paper is to present an outline of the bioactive peptides identified in the muscle protein of meat to date, with a focus on muscle protein from domestic animals and fish. The majority of research on bioactives from meat sources has focused on angiotensin-1-converting enzyme (ACE) inhibitory and antioxidant peptides

Caffeine use in the 21st Century: Considerations for public health

Caffeine has been consumed for thousands of years, with the primary sources originally being tea leaves and coffee beans. However, over the past 120 years new caffeinated foods and beverages have been developed and marketed worldwide, which has led to an increase in caffeine consumption in both children and adults. Concomitant with the rise in caffeine consumption has been a rise in the number of caffeine-induced incidents leading to emergency room visits or calls to poison centres. The reasons for the increases in caffeine consumption and related health concerns are likely to be multi-factorial and include aspects such as the wide range of caffeine sources available, the variability in caffeine content between and within products, lack of knowledge by the consumer, compounded by the wide variety of reasons for its consumption. In addition, with the advent of caffeinated products such as energy drinks and ready-to-drink beverages which frequently contain high levels of sugar, alcohol or other stimulatory compounds, adjuvant effects are possible. Life in the 21st century is faster and more competitive than it has ever been, and lifestyles are constantly changing to reflect that. Although consumption of increasingly accessible caffeinated beverages may aid in achieving life’s goals, the question remains as to how this increased consumption may impact on health, particularly in the long term. The aim of this review is to explore the above issues in an effort to raise awareness and stimulate discussion as to future public health concerns.fals

the potential for enhancement of immunity in cats by dietary supplementation

This study was conducted to examine the potential benefits of dietary supplementation on the feline immune system. Forty three cats (8 or 9 per group) were fed a low protein control diet (22.7% DM basis), the same diet supplemented with yeast-derived nucleotides, salmon oil or l-arginine or a commercial moist high protein diet (53.0% DM basis) for a period of five weeks. The low protein diets were formulated using a commercial moist diet base with added fat and starch and fed ad libitum, along with water. Specific immune assays showed that supplementation with arginine caused a significant enhancement of lymphocyte proliferative responses to the T-cell mitogen PHA after 35 days (P = 0.018), while supplementation with either nucleotides or salmon oil resulted in significant enhancement after both 14 (P = 0.0048, P <0.0001 respectively) and 35 days (both P <0.0001). Dietary supplementation with arginine, nucleotides or salmon oil each led to significant increases in blood leucocyte phagocytic activity after both 14 (P = 0.0003, P = 0.0077, P <0.0001 respectively) and 35 days (P <0.0001). This indicates that a number of dietary ingredients have the ability to modulate the immune system of healthy cats possibly resulting in a greater ability to fight infection and diseas

The Role of Genetics in Moderating the Inter-Individual Differences in the Ergogenicity of Caffeine

Caffeine use is widespread among athletes following its removal from the World Anti-Doping Agency banned list, with approximately 75% of competitive athletes using caffeine. While literature supports that caffeine has a small positive ergogenic effect for most forms of sports and exercise, there exists a significant amount of inter-individual difference in the response to caffeine ingestion and the subsequent effect on exercise performance. In this narrative review, we discuss some of the potential mechanisms and focus on the role that genetics has in these differences. CYP1A2 and ADORA2A are two of the genes which are thought to have the largest impact on the ergogenicity of caffeine. CYP1A2 is responsible for the majority of the metabolism of caffeine, and ADORA2A has been linked to caffeine-induced anxiety. The effects of CYP1A2 and ADORA2A genes on responses to caffeine will be discussed in detail and an overview of the current literature will be presented. The role of these two genes may explain a large portion of the inter-individual variance reported by studies following caffeine ingestion. Elucidating the extent to which these genes moderate responses to caffeine during exercise will ensure caffeine supplementation programs can be tailored to individual athletes in order to maximize the potential ergogenic effect