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Full-Text Articles in Veterinary Toxicology and Pharmacology

Embryotoxic Effects Of Three Natural Occurring Veratrum Alkaloids And One Synthetic Analog Using In Vitro Produced Bovine Embryos, Kevin D. Welch, Shiquan Wang, Stephen T. Lee, Dale R. Gardner, Kip E. Panter Dec 2023

Embryotoxic Effects Of Three Natural Occurring Veratrum Alkaloids And One Synthetic Analog Using In Vitro Produced Bovine Embryos, Kevin D. Welch, Shiquan Wang, Stephen T. Lee, Dale R. Gardner, Kip E. Panter

Poisonous Plant Research (PPR)

Three natural occurring plant toxins from Veratrum californicum and one related synthetic analog were screened for embryotoxicity using in vitro bovine embryo production techniques. Bovine oocytes were aspirated from ovaries collected from a local abattoir and embryos were generated through in vitro maturation (IVM) and in vitro culture (IVC) procedures. The three natural steroidal alkaloids, cyclopamine, jervine and veratramine and the synthetic steroidal derivative of cyclopamine, cyclopamine-4-en-3-one, were added to IVM and IVC media at 12 μM. Oocytes were exposed to the toxins during maturation (IVM) and pre-implantation embryo during culture (IVC). Cleavage rates and embryo growth (morula and blastocyst …


The Comparative Cytotoxicity Of Riddelliine In Primary Mouse, Rat And Chick Hepatocytes, Bryan L. Stegelmeier, William S. Resager, Steven M. Colegate May 2020

The Comparative Cytotoxicity Of Riddelliine In Primary Mouse, Rat And Chick Hepatocytes, Bryan L. Stegelmeier, William S. Resager, Steven M. Colegate

Poisonous Plant Research (PPR)

Dehydropyrrolizidine alkaloid (DHPA) producing plants commonly poison livestock, wildlife and humans. Poisoning occurs when DHPAs are ingested as feed or food, or when they contaminate medicinal or herbal products. Direct toxicologic comparison of individual DHPAs is essential to estimate their actual health risks. This has been problematic due to varying models and difficulties in DHPA isolation or synthesis. In contrast, the macrocyclic DHPA riddelliine is readily isolated and it has been used as a benchmark to characterize different models of toxicity and carcinogenicity. Following earlier work with immortalized cell lines, the objective of this study was to characterize the effect …


Dynamics Of Larkspur (Delphinium Barbeyi) Pellet Consumption And Tolerance Of The Inhibitory Effects Of Larkspur Alkaloids On Muscle Function In Cattle., Benedict T. Green, Jim Pfister, Dale Gardner, Kevin Welch, Daniel Cook Apr 2020

Dynamics Of Larkspur (Delphinium Barbeyi) Pellet Consumption And Tolerance Of The Inhibitory Effects Of Larkspur Alkaloids On Muscle Function In Cattle., Benedict T. Green, Jim Pfister, Dale Gardner, Kevin Welch, Daniel Cook

Poisonous Plant Research (PPR)

Larkspurs (Delphinium spp.) are toxic native plants on foothill and mountain rangelands in western North America, which poison cattle grazing on those rangelands. The purpose of this study was to examine in a laboratory setting, the subclinical effects of larkspur intake and toxicosis, by allowing larkspur susceptible and resistant cattle to self-select the amount of larkspur consumed in pellet form. We hypothesized that there would be differences in short term (9 – 11 day) pellet consumption between susceptible and resistant animals. Two trials were completed, each with larkspur resistant and susceptible Angus steers, and larkspur-alfalfa pellets at a 12% …


North American Hard Yellow Liver Disease: An Old Problem Readdressed, Bryan L. Stegelmeier, Meredyth Jones, Christopher P. Womack, T Zane Davis, Dale R. Gardner Oct 2019

North American Hard Yellow Liver Disease: An Old Problem Readdressed, Bryan L. Stegelmeier, Meredyth Jones, Christopher P. Womack, T Zane Davis, Dale R. Gardner

Poisonous Plant Research (PPR)

Hard yellow liver disease or fatty cirrhosis periodically affects cattle, sheep, goats, pronghorn antelope (Antilocapra americana) and whitetail deer (Odocoileus virginianus texanus) within several Texas counties in the United States. Clinically it presents as chronic liver disease with progressive hepatic necrosis and fibrosis, icterus and liver failure. The damaged livers are yellow and many have multiple firm, often gritty foci that are scattered throughout all lobes. Early investigations included feeding studies using potential toxic plants, climate and forage studies, infectious disease surveys and various mycotoxin studies and analyses. None have definitively reproduced the disease or identified the inciting …