Orally administered clonidine as a secretagogue of growth hormone and as a thymotrophic agent in dogs of various ages

Wallace B. Morrison From the Departments of Veterinary Clinical Sciences (Morrison), Veterinary Microbiology and Preventive Medicine (Roth, Goff, Stewart-Brown), and Veterinary Pathology (Arp), College of Veterinary Medicine, Iowa State University, Ames, IA 50011, and Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (Incefy).

Search for other papers by Wallace B. Morrison in
Current site
Google Scholar
PubMed
Close
 DVM, MS
,
Belinda Lawler Goff From the Departments of Veterinary Clinical Sciences (Morrison), Veterinary Microbiology and Preventive Medicine (Roth, Goff, Stewart-Brown), and Veterinary Pathology (Arp), College of Veterinary Medicine, Iowa State University, Ames, IA 50011, and Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (Incefy).

Search for other papers by Belinda Lawler Goff in
Current site
Google Scholar
PubMed
Close
 PhD
,
Barbara Stewart-Brown From the Departments of Veterinary Clinical Sciences (Morrison), Veterinary Microbiology and Preventive Medicine (Roth, Goff, Stewart-Brown), and Veterinary Pathology (Arp), College of Veterinary Medicine, Iowa State University, Ames, IA 50011, and Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (Incefy).

Search for other papers by Barbara Stewart-Brown in
Current site
Google Scholar
PubMed
Close
 DVM
,
Genevieve S. Incefy From the Departments of Veterinary Clinical Sciences (Morrison), Veterinary Microbiology and Preventive Medicine (Roth, Goff, Stewart-Brown), and Veterinary Pathology (Arp), College of Veterinary Medicine, Iowa State University, Ames, IA 50011, and Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (Incefy).

Search for other papers by Genevieve S. Incefy in
Current site
Google Scholar
PubMed
Close
 PhD
,
Lawrence H. Arp From the Departments of Veterinary Clinical Sciences (Morrison), Veterinary Microbiology and Preventive Medicine (Roth, Goff, Stewart-Brown), and Veterinary Pathology (Arp), College of Veterinary Medicine, Iowa State University, Ames, IA 50011, and Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (Incefy).

Search for other papers by Lawrence H. Arp in
Current site
Google Scholar
PubMed
Close
 DVM, PhD
, and
James A. Roth From the Departments of Veterinary Clinical Sciences (Morrison), Veterinary Microbiology and Preventive Medicine (Roth, Goff, Stewart-Brown), and Veterinary Pathology (Arp), College of Veterinary Medicine, Iowa State University, Ames, IA 50011, and Memorial Sloan-Kettering Cancer Center, New York, NY 10021 (Incefy).

Search for other papers by James A. Roth in
Current site
Google Scholar
PubMed
Close
 DVM, PhD

Click on author name to view affiliation information

SUMMARY

The growth hormone (gh) secretagogue activity of variable dosages of clonidine (16.5, 50, 150, and 450 μg/kg of body weight), given orally mixed with the daily food ration, was evaluated in young and old dogs. Significant (P < 0.05) increase in plasma gh concentration was detected at all dosages tested in young dogs and in response to all but the lowest dose tested in the old dogs fed the clonidine-containing diet. Old dogs had plasma gh concentration that exceeded that of young dogs when higher doses of clonidine were used.

A clonidine (100 μg/kg)-supplemented diet was fed to middle-aged dogs twice daily for 30 days. Significant (P < 0.01) increase of plasma gh concentration was observed on the first day of the feeding trial, but was undetectable by day 30. After feeding the clonidine-enhanced diet for 30 days, the effects on thymic morphology were variable, and there was no effect on plasma thymulin titer. Clonidine-fed dogs had significantly increased lymphocyte blastogenic responsiveness to mitogens, compared with that of control dogs, when evaluated as stimulation index.

SUMMARY

The growth hormone (gh) secretagogue activity of variable dosages of clonidine (16.5, 50, 150, and 450 μg/kg of body weight), given orally mixed with the daily food ration, was evaluated in young and old dogs. Significant (P < 0.05) increase in plasma gh concentration was detected at all dosages tested in young dogs and in response to all but the lowest dose tested in the old dogs fed the clonidine-containing diet. Old dogs had plasma gh concentration that exceeded that of young dogs when higher doses of clonidine were used.

A clonidine (100 μg/kg)-supplemented diet was fed to middle-aged dogs twice daily for 30 days. Significant (P < 0.01) increase of plasma gh concentration was observed on the first day of the feeding trial, but was undetectable by day 30. After feeding the clonidine-enhanced diet for 30 days, the effects on thymic morphology were variable, and there was no effect on plasma thymulin titer. Clonidine-fed dogs had significantly increased lymphocyte blastogenic responsiveness to mitogens, compared with that of control dogs, when evaluated as stimulation index.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 34 34 7
PDF Downloads 21 21 1
Advertisement