PROTEINS AND AMINO ACIDS Flashcards
Dimethyl sulfide - plants
-mustards (Brassica)
Dimethyl sulfide - MOA
- plant contains 5-methyl cysteine sulfide which is reduced by intestinal flora in monogastrics and rumen microflora to dimethyl sulfide
- lots of dimethyl sulfide = oxidation of RBCs –> HEINZ BODIES
Dimethyl sulfide CS
-signs of anemia (Depression, icterus, hemoglobinemia, hemoglobinuria, cyanosis, icterus)
Diterpene esters - plants
-Toxic spurges (Euphorbia): Candelabra cactus Christmas candle Pointsettia Croton Crown of thorns Physic nut Coral tree Cat tail Peregrina Cassava Sandbox tree Manchineel
Diterpene esters MOA
- direct irritation of skin and mm
- activate protein kinase C, resulting in cell damage and enzyme dysfunction
Diterpene esters CS
- irritation and blistering of skin and GIT mucosa –> salivation, vomiting, diarrhea
- signs are usually mild in small animals but may be severe in large animals, especially horses
Grayanotoxins - plants
-Heath family: common ornamental plants Rhododendron / Azalea Mountain laurel Japanese pieris Doghobble Maleberry
Grayanotoxins MOA
*All body/organ systems
-Bind to sodium channels in excitable cells (nerve, skeletal muscle,
cardiac muscle, CNS)
-Increase permeability of sodium ions and depolarization
-Irritation of the GI mucosa
Grayanotoxins CS
-GI signs including excessive salivation, vomiting or regurgitation,
colic, and diarrhea
-Other signs include depression, recumbency, tachycardia, tachypnea, seizures, and fever
-Death is usually due to aspiration pneumonia
Lectins: other names
phytotoxins
toxalbumins
Lectins: plants
- Castor bean (Ricinus communis; seeds look like ticks; used as laxative)
- Precatory bean (jumping bean, crab eye, devil’s eye)
- Coral Plant
- Sandbox tree
- Black locust
- Beans (soybeans, kidney, pinto, navy)
Lectins: MOA
- ricin and abrin are glycoproteins
- inhibit cellular protein synthesis –> cell death (GI mucosa, vascular endothelium, liver, cardiac, other tissue damage)
Lectins CS
-GIT signs; hemorrhagic gastroenteritis
Meliatoxins - plants
-Tetranortriterpenes (cytotoxic limonoid
concentrated in the fruit)
-Plant = Chinaberry (melia azedarach)
Meliatoxins MOA
enterotoxic, neurotoxic
Meliatoxins CS
- GI signs with or without blood
- CNS and peripheral neuronal signs generally similar to nicotine poisoning
- Death is from respiratory failure
Propyl disulfide - plants
onion, garlic, shallots, chives, leek
Amaryllis family
Propyl disulfide MOA
- disulfides produce oxygen free radicals, which cause damage of RBC membranes and HEMOLYSIS
- free radicals also cause denaturation of hemoglobin resulting in Heinz bodies
Propyl disulfide CS
-anorexia, ataxia, tachycardia, dyspnea, icterus, onion odor, abortion
Tetradymol plants
horsebrush
Tetradymol MOA
• Tetradymol from horsebrush causes liver damage that decreases elimination of phylloerythrin (a photodynamic metabolite of chlorophyll) –> damage in microcirculation areas exposed to ultraviolet light and photosensitization in white skin or lightly pigmented skin
*HEPATOGENIC PHOTOSENSITIZATION
Tetradymol CS
- Sheep are the most susceptible animals
- sudden onset of anorexia, depression, incoordination, dyspnea, and probably icterus and head pressing
- Skin swelling, erythema, necrosis,and sloughing
- Secondary bacterial infections
Thiaminase plants
horsetail
bracken fern
Thiaminase MOA
thiaminase destroys thiamine in diet and produces signs of thiamine (B1) deficiency in monogastric animals (neurotoxic)
Triterpenoid saponins plants
- alfalfa
- holly
- ginseng family (English/common ivy)
- pokeweed
Triterpenoid saponins MOA
direct irritation of GIT mucosa
Triterpenoid saponins CS
salivation, anorexia, vomiting, diarrhea, colic, hypothermia
