Treatment of growth hormone excess in dogs with the progesterone receptor antagonist aglépristone.
Acromegaly or hypersomatotropism in dogs is almost always due to progestin-induced hypersecretion of GH originating from the mammary gland. The aim of this study was to investigate whether aglépristone, a progesterone receptor antagonist, can be used to treat this form of canine acromegaly. In five Beagle bitches hypersomatotropism was induced by administration of MPA for over 1 year. Subsequently, aglépristone was administered. Blood samples were collected before MPA administration, immediately before, during, and 3.5 and 5.5 weeks after the last administration of aglépristone for determination of the plasma concentrations of GH and IGF-I. In addition, blood samples for the determination of the 6-h plasma profile of GH were collected before MPA administration, before aglépristone administration, and 1 week after the last aglépristone treatment. MPA administration resulted in a significant increase of the mean plasma IGF-I concentration, whereas analysis of the pulsatile plasma profile demonstrated a trend (P=0.06) for a higher mean basal plasma GH concentration and a higher mean AUC(0) for GH. Treatment with aglépristone resulted in a significant decrease of the mean plasma GH and IGF-I concentrations. Analysis of the pulsatile plasma profile showed a trend (P=0.06) for a lower mean basal plasma GH concentration and a lower mean AUC(0) for GH 1 week after the last aglépristone treatment compared with these values before aglépristone administration. Three and a half and 5.5 weeks after the last aglépristone administration the mean plasma IGF-I concentration increased again. In conclusion, aglépristone can be used successfully to treat dogs with progestin-induced hypersomatotropism.
Department of Small Animal Medicine and Clinical Biology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium. Sofie.Bhatti@UGent.be
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Bhatti
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Duchateau
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Okkens
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Van Ham
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Mol
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Kooistra
D000172:Acromegaly / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism / Q000662:veterinary; D000818:Animals; D002940:Circadian Rhythm / Q000502:physiology; D004283:Dog Diseases / Q000139:chemically induced / Q000188:drug therapy* / Q000378:metabolism; D004285:Dogs; D004963:Estrenes / Q000627:therapeutic use*; D005260:Female; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism*; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D017258:Medroxyprogesterone Acetate / Q000008:administration & dosage / Q000009:adverse effects; D011673:Pulsatile Flow / Q000187:drug effects; D011980:Receptors, Progesterone / Q000037:antagonists & inhibitors*; D013997:Time Factors
D004963:Estrenes; D011980:Receptors, Progesterone; C419063:aglepristone; D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone; D017258:Medroxyprogesterone Acetate