Chemistry
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| Felinine | MMB |
Cauxin is a carboxylesterase that is excreted in large amounts in cat urine. There is also evidence that it can serve as a peptide hydrolase in the production of cat pheromone precursors. [1] [2] Cauxin has a mass of 70 kilodaltons and is composed of 545 amino acids. [3] The protein can also exist as a multimeric protein complex connected by disulfide bonds with a mass of 300-350 kilodaltons. This is its primary form in non-reducing conditions. [2] [3] The proximal tubules of epithelial cells in the kidney express cauxin. This protein is secreted into the urine from the renal tubular cells. [4] The gene for the protein is also found in several other mammalian genomes in various organs. However, the only mammals that have cauxin present in urine are cats. It is also the first carboxylesterase to be found in urine. [3]
Cauxin has been shown to hydrolyze 3-methylbutanol-cysteinylglycine (3-MBCG) in the urine into felinine which then slowly degrades into the putative, sulfur-containing cat pheromone 3-mercapto-3-methylbutan-1-ol (MMB). [1] This pheromone is used to mark territory with urine. [1]
Neutered male cats have less cauxin in their urine than do intact males. [5] Intact males also have higher levels of cauxin than females and higher levels than kittens. This, in addition to cauxin's role in pheromone production, suggests that it is also involved in sexual signaling. [1]
Cauxin or its homologs are present in many cat species. These homologs are highly conserved and also exist as multimers. However, the cauxin concentrations in urine seems to vary depending on the species with larger species generally having lower concentrations in urine than smaller domestic cats. This is likely a result of decreased reliance on felinine, due to the existence of additional, more complex signaling molecules that are present in the urine of larger cats. [2]
Cauxin is also present in the seminal fluid of cats and several other mammals, including sheep, pigs, cattle, rams, boars, rats, and mice. [6] [7] The cauxin found in seminal fluid is produced by epidydimal cells. The concentration in seminal fluid is much lower than its concentration of urine. The role of cauxin as an esterase allows it to hydrolyze specific monoacylglycerols, suggesting that it is involved in lipid transfer and metabolism. It is also theorized to play a role in fertilization. [6]
Cauxin protein from feline urine was reported in 2008 to act as a nucleator for struvite crystals, in an in vivo system containing magnesium, ammonium, and phosphate ions. [8] Thus, this protein may act as one cause for feline urinary stones.
Decreased cauxin concentration of urine is also a marker of tubulointerstitial nephritis in cats, a common illness in older domestic cats. This is due to damage to the tubular cells where excreted cauxin is produced. [9]
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| Felinine | MMB |
The cat is a domestic species of small carnivorous mammal. It is the only domesticated species in the family Felidae and is commonly referred to as the domestic cat or house cat to distinguish it from the wild members of the family. Cats are commonly kept as house pets but can also be farm cats or feral cats; the feral cat ranges freely and avoids human contact. Domestic cats are valued by humans for companionship and their ability to kill vermin. About 60 cat breeds are recognized by various cat registries.
Kidney stone disease, also known as nephrolithiasis or urolithiasis, is a crystallopathy where a solid piece of material develops in the urinary tract. Kidney stones typically form in the kidney and leave the body in the urine stream. A small stone may pass without causing symptoms. If a stone grows to more than 5 millimeters, it can cause blockage of the ureter, resulting in sharp and severe pain in the lower back or abdomen. A stone may also result in blood in the urine, vomiting, or painful urination. About half of people who have had a kidney stone are likely to have another within ten years.
Proteinuria is the presence of excess proteins in the urine. In healthy persons, urine contains very little protein; an excess is suggestive of illness. Excess protein in the urine often causes the urine to become foamy. Severe proteinuria can cause nephrotic syndrome in which there is worsening swelling of the body.
A urine test is any medical test performed on a urine specimen. The analysis of urine is a valuable diagnostic tool because its composition reflects the functioning of many body systems, particularly the kidneys and urinary system, and specimens are easy to obtain. Common urine tests include the routine urinalysis, which examines the physical, chemical, and microscopic properties of the urine; urine drug screening; and urine pregnancy testing.
Struvite (magnesium ammonium phosphate) is a phosphate mineral with formula: NH4MgPO4·6H2O. Struvite crystallizes in the orthorhombic system as white to yellowish or brownish-white pyramidal crystals or in platy mica-like forms. It is a soft mineral with Mohs hardness of 1.5 to 2 and has a low specific gravity of 1.7. It is sparingly soluble in neutral and alkaline conditions, but readily soluble in acid.
Lysinuric protein intolerance (LPI) is an autosomal recessive metabolic disorder affecting amino acid transport.
Feline lower urinary tract disease (FLUTD) is a generic category term to describe any disorder affecting the bladder or urethra of cats.
A kairomone is a semiochemical, emitted by an organism, which mediates interspecific interactions in a way that benefits an individual of another species which receives it and harms the emitter. This "eavesdropping" is often disadvantageous to the producer. The kairomone improves the fitness of the recipient and in this respect differs from an allomone and a synomone. The term is mostly used in the field of entomology. Two main ecological cues are provided by kairomones; they generally either indicate a food source for the receiver, or the presence of a predator, the latter of which is less common or at least less studied.
Cats need to communicate with each other for bonding, and relating with each other; they need to collaborate, play, and share resources. When they communicate with people, they do so to get what they need or want, such as food, affection, or play.
Bladder stones or uroliths are a common occurrence in animals, especially in domestic animals such as dogs and cats. Occurrence in other species, including tortoises, has been reported as well. The stones form in the urinary bladder in varying size and numbers secondary to infection, dietary influences, and genetics. Stones can form in any part of the urinary tract in dogs and cats, but unlike in humans, stones of the kidney are less common and do not often cause significant disease, although they can contribute to pyelonephritis and chronic kidney disease. Types of stones include struvite, calcium oxalate, urate, cystine, calcium phosphate, and silicate. Struvite and calcium oxalate stones are by far the most common. Bladder stones are not the same as bladder crystals but if the crystals coalesce unchecked in the bladder they can become stones.
Cat behavior is a cat's behavior and responses to events and other stimuli. Cat behavior includes body language, elimination habits, aggression, play, communication, hunting, grooming, urine marking, and face rubbing. It varies among individuals, colonies, and breeds.
Protein C inhibitor is a serine protease inhibitor (serpin) that limits the activity of protein C.
A cat pheromone is a chemical molecule, or compound, that is used by cats and other felids for communication. These pheromones are produced and detected specifically by the body systems of cats and evoke certain behavioural responses.
Felinine, also known as (R)-2-amino-3-(4-hydroxy-2-methylbutan-2-ylthio)propanoic acid, is a chemical compound and amino acid found in cat urine and a precursor via microbial lyase of the putative cat pheromone and thiol called 3-mercapto-3-methylbutan-1-ol (MMB). Felinine is excreted by selected Felidae species including bobcats, Chinese desert cats, the kodkod, and domestic cats.
3-Mercapto-3-methylbutan-1-ol, also known as MMB, is a common odorant found in food and cat urine. The aromas ascribed to MMB include catty, roasty, broth-like, meaty, and savory, or similar to cooked leeks.
The enzyme carboxylesterase (or carboxylic-ester hydrolase, EC 3.1.1.1; systematic name carboxylic-ester hydrolase) catalyzes reactions of the following form:
Feline idiopathic cystitis (FIC) or feline interstitial cystitis or cystitis in cats, is one of the most frequently observed forms of feline lower urinary tract disease (FLUTD). Feline cystitis means "inflammation of the bladder in cats". The term idiopathic means unknown cause; however, certain behaviours have been known to aggravate the illness once it has been initiated. It can affect both males and females of any breed of cat. It is more commonly found in female cats; however, when males do exhibit cystitis, it is usually more dangerous.
Major urinary proteins (Mups), also known as α2u-globulins, are a subfamily of proteins found in abundance in the urine and other secretions of many animals. Mups provide a small range of identifying information about the donor animal, when detected by the vomeronasal organ of the receiving animal. They belong to a larger family of proteins known as lipocalins. Mups are encoded by a cluster of genes, located adjacent to each other on a single stretch of DNA, that varies greatly in number between species: from at least 21 functional genes in mice to none in humans. Mup proteins form a characteristic glove shape, encompassing a ligand-binding pocket that accommodates specific small organic chemicals.
Nepetalactol is an iridoid. It is produced from 8-oxogeranial by the enzyme iridoid synthase. Nepetalactol is a substrate for the enzyme iridoid oxidase (IO) which produces 7-deoxyloganetic acid. It has been identified in Actinidia polygama as a major cat attractant, and a mosquito repellent. The fact that mosquitos bite cats with nepetalactol on their fur less often may explain why cats are attracted to silver vine in the first place.
Feline morbillivirus comes from the genus Morbillivirus, specifically influencing wild and domestic cats. The first report of a Feline morbillivirus outbreak occurred in Hong Kong in 2012. Approximately 10% of stray cats in Hong Kong and mainland China were reported to possess the virus at the time with additional infections found in Japan as well. 40% of cats tested in Japan were Fmo-PV positive and exhibited early symptoms of kidney failure. While the first cases of Feline morbillivirus were found in China, Hong Kong and Japan, the virus can also be found in Italy, Germany, and the United States. Feline morbillivirus exhibits a substantial amount of genetic diversity, yet cases in Japan and Hong Kong proved to have identical nucleotide sequences. It is also hypothesized that the morbillivirus has high adaptability due to its presence in multiple species. It is often found in dogs, cats, cattle, whales, dolphins, porpoises, and even humans. It likely originated from an ancestral version and underwent viral evolution to adapt to transmission in different species. Other common morbilliviruses include measles, rinderpest virus, canine distemper virus and peste des petits ruminants virus.
