Digital Commons Network^™

The Federal Role In Regulating Alternative Livestock Operations, Jose R. Diez, Mike Gilsdorf, Robert Werge

Zoonotics and Wildlife Disease: Publications

This paper discusses one aspect of federal regulation for alternative livestock, namely that concerned with the health status of animal agriculture. Federal responsibility for animal health programs rests with Veterinary Services (VS), a unit of the Animal and Plant Health Inspection Service (APHIS), an agency of the United States Department of Agriculture (USDA). The objective of this paper is to briefly describe three aspects ofVS' policy that have a potential to impact alternative livestock as well as free ranging wildlife. These are (1) using cooperative state-federal programs to eliminate diseases in alternative livestock, (2) collaborating on health issues with a …

Preclinical Diagnosis Of Chronic Wasting Disease In Captive Mule Deer (Odocoileus Hemionus) And White-Tailed Deer (Odocoileus Virginianus) Using Tonsillar Biopsy, Margaret A. Wild, Terry R. Spraker, Christina J. Sigurdson, Katherine I. O'Rourke, Michael W. Miller

Zoonotics and Wildlife Disease: Publications

The usefulness of tonsillar biopsy on live deer for preclinical diagnosis of the transmissible spongiform encephalopathy chronic wasting disease (CWD) was evaluated. Disease was tracked in a CWD-endemic herd using serial tonsillar biopsies collected at 6 to 9 month intervals from 34 captive mule deer (Odocoileus hemionus) and five white-tailed deer (O. virginianus). Tonsillar biopsies were examined for accumulation of PrP^CWD, the protein marker for infection, using immunohistochemical (IHC) staining. 26/34 (76%) mule deer and 4/5 (80%) white-tailed deer had PrP^CWD accumulation in tonsillar biopsies; CWD was subsequently confirmed by post-mortem examination in …

Validation Of Monoclonal Antibody F99/97.6.1 For Immunohistochemical Staining Of Brain And Tonsil In Mule Deer (Odocoileus Hemionus) With Chronic Wasting Disease, T. R. Spraker, Katherine I. O'Rourke, A. Balachandran, R. R. Zink, B. A. Cummings, M. W. Miller, B. E. Powers

Zoonotics and Wildlife Disease: Publications

A new monoclonal antibody (MAb), F99/97.6.1, that has been used to demonstrate scrapieassociated prion protein PrP^Sc in brain and lymphoid tissues of domestic sheep with scrapie was used in an immunohistochemistry assay for diagnosis of chronic wasting disease (CWD) in mule deer (Odocoileus hemionus). The MAb F99/97.6.1 immunohistochemistry assay was evaluated in brain and tonsil tissue from 100 mule deer that had spongiform encephalopathy compatible with CWD and from 1,050 mule deer outside the CWD-endemic area. This MAb demonstrated abnormal protease-resistant prion protein (PrP^res) in brains of all of the 100 mule deer and in …

Pregnancy Status And Fetal Prion Genetics Determine PrpSc Accumulation In Placentomes Of Scrapieinfected Sheep, Wenbin Tuo, Katherine I. O'Rourke, Dongyue Zhuang, William P. Cheevers, Terry R. Spraker, Donald P. Knowles

Zoonotics and Wildlife Disease: Publications

Ovine scrapie is a fatal neurodegenerative disorder that may be transmitted through exposure to infected uterine and placental tissues. Susceptibility to scrapie is primarily controlled by polymorphisms in the prion protein (PrP) gene. Scrapie in the U.S. Suffolk breed and in many breeds in Europe occurs in sheep homozygous for glutamine (171QQ), but rarely in sheep heterozygous for glutamine and arginine (171QR) or homozygous for arginine (171RR) at codon 171 of the PrP gene. This study demonstrated that accumulation of PrP^Sc in uterine-placental epithelial cells in the placentome was determined by fetal PrP genotype and the pregnancy status of …

Active Surveillance For Scrapie By Third Eyelid Biopsy And Genetic Susceptibility Testing Of Flocks Of Sheep In Wyoming, Katherine I. O'Rourke, John V. Duncan, James R. Logan, Anne K. Anderson, Dianne K. Norden, Elizabeth S. Williams, Bret A. Combs, Robert H. Stobart, Gary E. Moss, Diane L. Sutton

Zoonotics and Wildlife Disease: Publications

Control of scrapie, an ovine transmissible spongiform encephalopathy or prion disorder, has been hampered by the lack of conventional antemortem diagnostic tests. Currently, scrapie is diagnosed by postmortem examination of the brain and lymphoid tissues for PrP^Sc, the protein marker for this group of disorders. For live, asymptomatic sheep, diagnosis using tonsil or third-eyelid lymphoid tissue biopsy and PrP^Sc assay has been described. To evaluate the feasibility and efficacy of third-eyelid testing for identification of infected flocks and individual infected sheep, 690 sheep from 22 flocks were sampled by third-eyelid lymphoid tissue biopsy and immunohistochemistry. Sheep were …

Comparison Of Histological Lesions And Immunohistochemical Staining Of Proteinase-Resistant Prion Protein In A Naturally Occurring Spongiform Encephalopathy Of Free-Ranging Mule Deer (Odocoileus Hemionus) With Those Of Chronic Wasting Disease Of Captive Mule Deer, T. R. Spraker, R. R. Zink, B. A. Cummings, M. A. Wild, M. W. Miller, Katherine I. O'Rourke

Zoonotics and Wildlife Disease: Publications

In this investigation, the nature and distribution of histologic lesions and immunohistochemical staining (IHC) of a proteinase-resistant prion protein were compared in free-ranging mule deer (Odocoileus hemionus) dying of a naturally occurring spongiform encephalopathy (SE) and captive mule deer dying of chronic wasting disease (CWD). Sixteen free-ranging deer with SE, 12 free-ranging deer without SE, and 10 captive deer with CWD were examined at necropsy. Tissue sections were stained with hematoxylin and eosin, and duplicate sections were stained with a monoclonal antibody (F89/160.1.5). Histological lesions in the freeranging deer with SE and captive deer with CWD were found …

Department Of Veterinary And Biomedical Sciences: 2002 Annual Report

School of Veterinary and Biomedical Sciences: Information and History

Foreword 2002
VBMS Faculty
VBMS Faculty and Staff, by Function and Unit
Honors. Awards and Recognitions. 2002
VBMS Committee Assignments. 2002
Faculty Profiles
VBMS Research Associates Profiles
VBMS Teaching Program
Great Plains Veterinary Educational Center (GPVEC)
VBMS Research Program
International Activities
Veterinary Extension Program
Nebraska Veterinary Diagnostic Laboratory Systems (NVDLS)
VBMS Grants and Contracts Program
Patents by VBMS Faculty in 2002
Publications by VBMS Faculty
Presentations by VBMS Faculty
Articles Regarding the Department
Selected Committees. Editorial and Other Appointments
Departmental Budget Summaries
Nebraska Agricultural Statistics

Mechanisms Counteracting Swelling In Brain Cells During Hyponatremia, Herminia Pasantes-Morales, Rodrigo Franco, Benito Ordaz, Lenin D. Ochoa

School of Veterinary and Biomedical Sciences: Faculty Publications

Water gain in the brain consequent to hyponatremia is counteracted by mechanisms that initially include a compensatory displacement of liquid from the interstitial space to cerebrospinal fluid and systemic circulation and subsequently an active reduction in cell water accomplished by extrusion of intracellular osmolytes to reach osmotic equilibrium. Potassium (K⁺), chloride (Cl^–), amino acids, polyalcohols, and methylamines all contribute to volume regulation, with a major contribution of ions at the early phase and of organic osmolytes at the late phase of the regulatory process. Experimental models in vitro show that osmolyte fluxes occur via leak pathways …

Mycobacterium Bovis–Infected White-Tailed Deer (Odocoileus Virginianus): Detection Of Immunoglobulin Specific To Crude Mycobacterial Antigens By Elisa, W. Ray Waters, Mitchell V. Palmer, Diana L. Whipple

Michigan Bovine Tuberculosis Bibliography and Database

White-tailed deer (Odocoileus virginianus) have recently emerged as a source of Mycobacterium bovis infection for cattle within North America. The objective of this study was to evaluate the antibody response of M. bovis–infected deer to crude mycobacterial antigens. Deer were experimentally inoculated with M. bovis strain 1315 either by intratonsilar instillation or by exposure to M. bovis–infected (i.e., in contact) deer. To determine the time course of the response, including the effects of antigen administration for comparative cervical skin testing, serum was collected periodically and evaluated by enzyme-linked immunosorbent assay (ELISA) for immunoglobulin (i.e., IgG heavy …

Nitric Oxide Production As An Indication Of Mycobacterium Bovis Infection In White-Tailed Deer (Odocoileus Virginianus), W. R. Waters, M. V. Palmer, R. E. Sacco, D. L. Whipple

Michigan Bovine Tuberculosis Bibliography and Database

White-tailed deer ( Odocoileus virginianus ) are reservoirs for Mycobacterium bovis in northeast Michigan, USA. Production of nitric oxide (NO) by activated macrophages is a potent mechanism of mycobacterial killing. The capacity of macrophages to produce NO, however, varies among mammalian species. The objective of this study was to determine if mononuclear cells from white-tailed deer produce nitrite as an indication of NO production and, if so, is NO produced in response to stimulation with M. bovis antigens. Supernatants were harvested from adherent peripheral blood mononuclear cell (PBMC) cultures that had been stimulated with either Mannheimia haemolytica lipopolysaccharide (LPS) or …

Influence Of Protein Tyrosine Kinases On Cell Volume Change-Induced Taurine Release, Herminia Pasantes-Morales, Rodrigo Franco

School of Veterinary and Biomedical Sciences: Faculty Publications

Taurine efflux occurs in association with cell swelling in both hyposmotic and isosmotic conditions and during cell shrinkage in apoptotic death. Release occurs through a leak pathway, is largely Ca²⁺-independent and is sensitive to Cl^– channel blockers. Taurine efflux elicited by hyposmolarity is reduced or suppressed by tyrosine kinase blockers and increased by tyrosine phosphatase inhibitors. The specific kinases involved are still unknown and may be different in the various cell types. Non-receptor and scr-related protein kinases have been identified in some cells as elements that directly phosphorylate the taurine efflux pathway. Possible tyrosine kinase targets are …

Methods And Compositions For Protection Against Bovine Viral Diseases, Subramaniam Srikumaran

School of Veterinary and Biomedical Sciences: Faculty Publications

The present invention relates to methods and compositions for eliciting an immune response against bovine viral epitopes. The methods comprise combining at least one heat shock protein with at least one bovine viral epitope to form a purified epitope/heat shock protein complex and administration of an immune system stimulating amount of the purified epitope/heat shock protein complex. The compositions comprise, a purified epitope/heat shock protein complex comprising at least one bovine viral epitope complexed with at least one heat shock protein, and a pharmaceutically acceptable carrier, diluent or excipient.

Antipredator Conditioning In Mississippi Sandhill Cranes (Grus Canadensis Pulla), Jennifer Jill Heatley

LSU Master's Theses

The Mississippi Sandhill Crane (Grus canadensis pulla), the most endangered North American crane, is considered critically endangered and is protected by Federal and State law. Substantial funding has established the Mississippi Sandhill Crane National Wildlife Refuge in Southern Mississippi and an artificial insemination / breeding facility at the Audubon Center for Research of Endangered Species in New Orleans, Louisiana to promote species recovery. In spite of extensive time, labor, and money invested in captive propagation, juvenile Mississippi Sandhill Cranes suffer substantial mortality due to predation by bobcats (Lynx rufus), coyotes (Canis latrans) and red tailed hawks (Buteo jamaicensis) upon reintroduction …

Evidence For Two Mechanisms Of Amino Acid Osmolyte Release From Hippocampal Slices, R. Franco, M. E. Torres-Marquez, H. Pasantes-Morales

School of Veterinary and Biomedical Sciences: Faculty Publications

A 30% decrease in osmolarity stimulated ³H-taurine, ³H-GABA and glutamate (followed as ³H-D-aspartate) efflux from rat hippocampal slices. ³H-taurine efflux was activated rapidly but inactivated slowly. It was decreased markedly by 100 μM 5-nitro-(3-phenylpropylamino) benzoic acid (NPPB) and 600 μM niflumic acid and inhibited strongly by tyrphostins AG18, AG879 and AG112 (25–100 μM), suggesting a tyrosine kinase-mediated mechanism. Hyposmolarity activated the mitogen-activated protein kinases (MAPK) extracellular-signal-related kinase-1/2 (ERK1/ERK2) and p38, but blockade of this reaction did not affect ³H-taurine efflux. Hyposmosis also activated phosphatidyl-inositide 3-kinase (PI3K) and its prevention by wortmannin (100 nM) essentially abolished …

Capitalism And The Value Of Life: Foot-And-Mouth And The Culling Of Herds, Ibpp Editor

International Bulletin of Political Psychology

This article describes some psychological implications of culling as an intervention to help combat the spread of foot-and-mouth disease.

Trends. The Psycho-Politics Of Foot In Mouth On Foot In Mouth: Pigs, Sheep, Cows, Politicians On The Animal Farm, Ibpp Editor

International Bulletin of Political Psychology

This article discusses agricultural policy in the United Kingdom regarding foot and mouth disease of cloven-hoofed animals.

Infections With Ehrlichia Chaffeensis And Ehrlichia Ewingii In Persons Coinfected With Human Immunodeficiency Virus, Christopher D. Paddock, Scott M. Folk, G. Merrill Shore, Linda J. Machado, Mark M. Huycke, Leonard N. Slater, Allison M. Liddell, Richard S. Buller, Gregory A. Storch, Thomas P. Monson, David Rimland, John W. Sumner, Joseph Singleton, Karen C. Bloch, Yi-Wei Tang, Steven M. Standaert, James E. Childs

Zoonotics and Wildlife Disease: Publications

The clinical course and laboratory valuation of 21 patients coinfected with human immunodeficiency virus (HIV) and Ehrlichia chaffeensis or Ehrlichia ewingii are reviewed and summarized, including 13 cases of ehrlichiosis caused by E. chaffeensis, 4 caused by E. ewingii, and 4 caused by either E. chaffeensis or E. ewingii. Twenty patients were male, and the median CD4⁺ T lymphocyte count was 137 cells/μL. Exposures to infecting ticks were linked to recreational pursuits, occupations, and peridomestic activities. For 8 patients, a diagnosis of ehrlichiosis was not considered until ≥4 days after presentation. Severe manifestations occurred more frequently …

Prospective Assesment Of The Etiology Of Acute Febrile Illness After A Tick Bite In Slovenia, Stanka Lotric-Furlan, Miroslav Petrovec, Tatjana Avsic-Zupanc, William L. Nicholson, John W. Sumner, James E. Childs, Franc Strle

Zoonotics and Wildlife Disease: Publications

A prospective study established the etiology of febrile illnesses in residents of Slovenia that occurred within 6 weeks after a tick bite. A combination of laboratory and clinical criteria identified 64 (49.2%) of 130 patients as having confirmed, probable, or possible cases of tickborne disease during 1995 and 1996. Of the 130 patients, 36 (27.7%) had laboratory evidence of tickborne encephalitis, all of whom had clinically confirmed disease. Evidence of infection with Borreliab urgdorfersie sensu lato was identified in 26 patients; 10 (7.7%) had confirmed Lyme borreliosis. Of 22 patients with evidence of Ehrlichiap hagocytophila infection, 4 (3.1%) had confirmed …

Analysis Of Risk Factors For Fatal Rocky Mountain Spotted Fever: Evidence For Superiority Of Tetracyclines For Therapy, Robert C. Holman, Christopher D. Paddock, Aaron T. Curns, John W. Krebs, Jennifer H. Mcquiston, James E. Childs

Zoonotics and Wildlife Disease: Publications

Epidemiologic and clinical characteristics of fatal and nonfatal cases of Rocky Mountain spotted fever (RMSF) were compared to identify risk factors for death caused by this disease. Confirmed and probable RMSF cases reported through US national surveillance for 1981- 1998 were analyzed. Among 6388 RMSF patients, 213 died (annual case-fatality rate, 3M; range, 4.9 % in 1982 to 1.1 % in 1996). Use of tetracycline-class antibiotics for treatment of RMSF increased significantly in the 1990s, compared with use in the 1980s. Older patients, patients treated with chloramphenicol only, patients for whom tetracycline antibiotics were not the primary therapy, and patients …

Prp-C And Prp-Sc At The Fetal-Maternal Interface, Wenbin Tuo, Dongyue Zhuang, Donald P. Knowles, William P. Cheevers, Man-Sun Sy, Katherine I. O'Rourke

Zoonotics and Wildlife Disease: Publications

Scrapie is a naturally occurring prion (PrP) disease causing a fatal neurodegenerative disorder in sheep and goats. Previous studies suggest that scrapie is transmitted naturally through exposure to the scrapie agent in wasted placentas of infected ewes. This study determined the distribution and biochemical properties of PrP cellular (PrP-C) and the distribution of PrP scrapie (PrP-Sc) in reproductive, placental, and selected fetal tissues and fetal fluids in sheep. Glycosylated, N-terminally truncated, proteinase K-sensitive PrP-C with apparent molecular masses of 23–37 kDa was present in reproductive, placental, and fetal tissues and fetal fluids. PrP-C was low or undetectable in intercotyledonary chorioallantois, …

Immunohistochemical Detection Of Scrapie Prion Proteins In Clinically Normal Sheep In Pennsylvania, Hyun Kim, Katherine I. O'Rourke, Mark Walter, H. Graham Purchase, John Enck, Tae Kyun Shin

Zoonotics and Wildlife Disease: Publications

Following diagnosis of scrapie in a clinically suspect Suffolk sheep, 7 clinically normal flockmates were purchased by the Pennsylvania Department of Agriculture to determine their scrapie status using an immunohistochemical procedure. Two of the 7 euthanized healthy sheep had positive immunohistochemical staining of the prion protein of scrapie (PrP-Sc) in their brains, nictitating membranes, and tonsils. The PrP-Sc was localized in the areas of the brain where, histopathologically, there was neurodegeneration and astrocytosis. The PrP-Sc occurred within germinal centers of the affected nictitating membranes and tonsils and was located in the cytoplasm of the dendrite-like cells, lymphoid cells, and macrophages. …

Preliminary Findings On The Experimental Transmission Of Chronic Wasting Disease Agent Of Mule Deer To Cattle, Amir N. Hamir, Randall C. Cutlip, Janice M. Miller, Elizabeth S. Williams, Mick J. Stack, Michael W. Miller, Katherine I. O'Rourke, Melanie J. Chaplin

Zoonotics and Wildlife Disease: Publications

To determine the transmissibility of chronic wasting disease (CWD) to cattle and to provide information about clinical course, lesions, and suitability of currently used diagnostic procedures for detection of CWD in cattle, 13 calves were inoculated intracerebrally with brain suspension from mule deer naturally affected with CWD. Between 24 and 27 months postinoculation, 3 animals became recumbent and were euthanized. Gross necropsies revealed emaciation in 2 animals and a large pulmonary abscess in the third. Brains were examined for protease-resistant prion protein (PrP^res) by immunohistochemistry and Western blotting and for scrapie-associated fibrils (SAFs) by negative-stain electron microscopy. Microscopic …

Arbovirus Infection Increases With Group Size, Charles R. Brown, Nicholas Komar, Sunita B. Quick, Rajni A. Sethi, Nicholas A. Panella, Mary Bromberger Brown, Martin Pfeffer

Zoonotics and Wildlife Disease: Publications

Buggy Creek (BCR) virus is an arthropod-borne alphavirus that is naturally transmitted to its vertebrate host the cliff swallow (Petrochelidon pyrrhonota) by an invertebrate vector, namely the cimicid swallow bug (Oeciacus vicarius). We examined how the prevalence of the virus varied with the group size of both its vector and host. The study was conducted in southwestern Nebraska where cliff swallows breed in colonies ranging from one to 3700 nests and the bug populations at a site vary directly with the cliff swallow colony size. The percentage of cliff swallow nests containing bugs infected with BCR …

Department Of Veterinary And Biomedical Sciences: 2001 Annual Report, John A. Schmitz

School of Veterinary and Biomedical Sciences: Information and History

Twenty Departmental students completed their Bachelor of Science in Agricultural Science degrees in 2001, nineteen in the Veterinary Science Major and one in the Veterinary Technologist Major. Twenty-five Nebraska residents were admitted into the College of Veterinary Medicine at Kansas State University, twelve of them having completed all or part of their pre-veterinary studies at UNL. Seven students completed their Master of Science degree in Veterinary Science. Enrollment in the Distance Education MS in Veterinary Science Master of Science, Distance Education Program increased to seven students, with several applications still being processed or expected. Three new Distance Education courses were …

Re-Thinking The Summer Drenching Program, Brown Besier

Journal of the Department of Agriculture, Western Australia, Series 4

The summer drenching program has provided highly effective sheep worm control in Western Australia for many years - but recent research challenges its long term sustainability.

Trial results suggest that in large parts of the State, summer drenching is the main factor leading to the development of drench resistant worms. Alternative programs less likely to lead to drench resistance will require greater monitoring of worm burdens and panning pasture moves.

Legionella Pneumophila Entry Gene Rtxa Is Involved In Virulence, Suat L. G. Cirillo, Luis E. Bermudez, Sahar H. El-Etr, Gerald Duhamel, Jeffrey D. Cirillo

School of Veterinary and Biomedical Sciences: Faculty Publications

Successful parasitism of host cells by intracellular pathogens involves adherence, entry, survival, intracellular replication, and cell-to-cell spread. Our laboratory has been examining the role of early events, adherence and entry, in the pathogenesis of the facultative intracellular pathogen Legionella pneumophila. Currently, the mechanisms used by L. pneumophila to gain access to the intracellular environment are not well understood. We have recently isolated three loci, designated enh1, enh2, and enh3, that are involved in the ability of L. pneumophila to enter host cells. One of the genes present in the enh1 locus, rtxA, is homologous to repeats …

Blood Serum Concentrations Of Selenium And Glutathione Peroxidase Activity In Akkaraman Sheep, Taner Pamukçu, Tevhi̇de Sel, Gül Yarim

Turkish Journal of Veterinary & Animal Sciences

Selenium and other essential elements play an important role in animal husbandry. These elements help to minimize infectious diseases, reduce concomitant stresses and bring about optimal productive and reproductive performance. The mean serum selenium concentration of the sheep sampled in this study was 303.65 ng/ml. Such values are considered to be indicative of adequate dietary supplementation. Serum glutathione peroxidase activity in the sheep sampled in this study was also analysed, and the mean glutathione peroxidase activity was 3.65 nmolNADPH+H+/min/mg protein. It is recommended that producers monitor the selenium in serum in order to maintain adequate nutrition and performance in sheep.

Quarantine And Health Screening Protocols For Wildlife Prior To Translocation And Release Into The Wild, Michael H. Woodford

Zoonotics and Wildlife Disease: Publications

In recent years the translocation and release into the wild of wild-caught and captive-bred wild animals (mammals, birds, reptiles, amphibians and fish) has become a common practice, ostensibly for rehabilitation or conservation purposes. These wild animals comprise many varied taxa and the objectives of translocation and release may include:
(1) reintroducing a species that has become extinct in its natural range;
(2) restocking or reinforcing a population which has become depleted; and
(3) rehabilitating wild animals and birds which have been illegally captured and subsequently confiscated by Customs or national wildlife authorities. Welfare organizations also receive sick and injured wild …

Predicting The Local Dynamics Of Epizootic Rabies Among Raccoons In The United States, James E. Childs, Aaron T. Curns, Meghan E. Dey, Leslie A. Real, Lisa Feinstein, Ottar N. Bjørnstad, John W. Krebs

Zoonotics and Wildlife Disease: Publications

Mathematical models have been developed to explore the population dynamics of viral diseases among wildlife. However, assessing the predictions stemming from these models with wildlife databases adequate in size and temporal duration is uncommon. An epizootic of raccoon rabies that began in the mid-Atlantic region of the United States in the late 1970s has developed into one of the largest and most extensive in the history of wildlife rabies. We analyzed the dynamics of local epizootics at the county level by examining a database spanning more than 20 years and including 35,387 rabid raccoons. The size, number, and periodicity of …

Amino Acid Osmolytes In Regulatory Volume Decrease And Isovolumetric Regulation In Brain Cells: Contribution And Mechanisms, Herminia Pasantes-Morales, Rodrigo Franco, M. Eugenia Torres-Marquez, Karla Hernandez-Fonseca, Arturo Ortega

School of Veterinary and Biomedical Sciences: Faculty Publications

Brain adaptation to hyposmolarity is accomplished by loss of both electrolytes and organic osmolytes, including amino acids, polyalcohols and methylamines. In brain in vivo, the organic osmolytes account for about 35% of the total solute loss. This review focus on the role of amino acids in cell volume regulation, in conditions of sudden hyposmosis, when cells respond by active regulatory volume decrease (RVD) or after gradual exposure to hyposmotic solutions, a condition where cell volume remains unchanged, named isovolumetric regulation (IVR). The amino acid efflux pathway during RVD is passive and is similar in many respects to the volume-activated anion …