Morphological and cellular changes in secondary epidermal laminae of horses with insulin-induced laminitis

Ninja P. Karikoski Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, 00014 University of Helsinki, Finland.

Search for other papers by Ninja P. Karikoski in
Current site
Google Scholar
PubMed
Close
 DVM
,
Janet C. Patterson-Kane Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, Scotland.

Search for other papers by Janet C. Patterson-Kane in
Current site
Google Scholar
PubMed
Close
 PhD
,
Katie E. Asplin School of Veterinary Science, University of Queensland, Gatton, QLD 4343, Australia.

Search for other papers by Katie E. Asplin in
Current site
Google Scholar
PubMed
Close
 PhD
,
Thomas W. McGowan School of Veterinary Science, University of Queensland, Gatton, QLD 4343, Australia.

Search for other papers by Thomas W. McGowan in
Current site
Google Scholar
PubMed
Close
 PhD
,
Megan McNutt Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, Scotland.

Search for other papers by Megan McNutt in
Current site
Google Scholar
PubMed
Close
,
Ellen R. Singer Institute of Ageing and Chronic Disease, Faculty of Health and Life Sciences, University of Liverpool, Leahurst CH64 7TE, England

Search for other papers by Ellen R. Singer in
Current site
Google Scholar
PubMed
Close
 DVSc
, and
Catherine M. McGowan Acorn Veterinary Hospital, West Kirby CH48 4DD, England.

Search for other papers by Catherine M. McGowan in
Current site
Google Scholar
PubMed
Close
 PhD

Abstract

Objective—To determine cellular changes associated with secondary epidermal laminae (SEL) in forefeet and hind feet of ponies with insulin-induced laminitis.

Animals—8 ponies.

Procedures—Laminitis was induced in 4 ponies by IV administration of insulin and glucose; 4 control ponies received saline (0.9% NaCl) solution IV. Laminar tissue samples obtained from the dorsal aspects of the hooves were histologically evaluated. Primary epidermal lamina (PEL) length and width and SEL length, width, and angle were determined. Numbers of epidermal cell nuclei per micrometer and per total length of SEL and numbers of apoptotic and proliferative cells in axial, middle, and abaxial laminar regions were determined.

Results—SEL in treatment group ponies were significantly longer, were significantly narrower, and had a smaller angle relative to PEL in all laminar regions versus control ponies. In treatment group ponies, the number of epidermal cell nuclei per SEL was typically higher and the number of cells per micrometer of SEL was lower in laminar regions, apoptotic cell numbers were higher in abaxial and middle regions in forefeet and hind feet, and proliferating cell numbers were higher in axial laminar regions in forefeet and all laminar regions in hind feet, versus control ponies.

Conclusions and Clinical Relevance—Results indicated SEL elongation, narrowing, and alteration in orientation developed in all feet of ponies with insulin-induced laminitis. This was primarily attributable to cell stretching that developed at the same time as an accelerated cell death–proliferation cycle; differences in cell cycle responses among laminar regions between forefeet and hind feet may have been attributable to differences in load bearing.

Abstract

Objective—To determine cellular changes associated with secondary epidermal laminae (SEL) in forefeet and hind feet of ponies with insulin-induced laminitis.

Animals—8 ponies.

Procedures—Laminitis was induced in 4 ponies by IV administration of insulin and glucose; 4 control ponies received saline (0.9% NaCl) solution IV. Laminar tissue samples obtained from the dorsal aspects of the hooves were histologically evaluated. Primary epidermal lamina (PEL) length and width and SEL length, width, and angle were determined. Numbers of epidermal cell nuclei per micrometer and per total length of SEL and numbers of apoptotic and proliferative cells in axial, middle, and abaxial laminar regions were determined.

Results—SEL in treatment group ponies were significantly longer, were significantly narrower, and had a smaller angle relative to PEL in all laminar regions versus control ponies. In treatment group ponies, the number of epidermal cell nuclei per SEL was typically higher and the number of cells per micrometer of SEL was lower in laminar regions, apoptotic cell numbers were higher in abaxial and middle regions in forefeet and hind feet, and proliferating cell numbers were higher in axial laminar regions in forefeet and all laminar regions in hind feet, versus control ponies.

Conclusions and Clinical Relevance—Results indicated SEL elongation, narrowing, and alteration in orientation developed in all feet of ponies with insulin-induced laminitis. This was primarily attributable to cell stretching that developed at the same time as an accelerated cell death–proliferation cycle; differences in cell cycle responses among laminar regions between forefeet and hind feet may have been attributable to differences in load bearing.

All Time Past Year Past 30 Days
Abstract Views 87 0 0
Full Text Views 1889 1574 560
PDF Downloads 370 176 22
Advertisement